Week 34 – PLATO

“Ticagrelor versus Clopidogrel in Patients with Acute Coronary Syndromes”

by The Study of Platelet Inhibition and Patient Outcomes (PLATO) investigators

N Engl J Med. 2009 Sep 10;361(11):1045-57. [free full text]

In patients with acute coronary syndrome (ACS), with or without ST-segment elevation, clinical practice guidelines recommend dual antiplatelet therapy with aspirin plus one of either clopidogrel, prasugrel, or ticagrelor to reduce risk of thrombosis. The 2009 PLATO trial was designed to determine whether ticagrelor was superior to clopidogrel for the prevention of vascular events and death in patients presenting with ACS as well as whether this potential benefit came with an increased risk of major bleeding events.

Population:
Patients hospitalized for ACS with or without ST-elevations with symptom onset during the previous 24 hours.

If there were no ST-elevations, patients were required to have at least 2 of 3 of the following: ST change reflecting ischemia, elevated cardiac biomarkers (i.e. troponin), or one of several risk factors (age ≥ 60, prior MI/CABG, CAD w/ ≥ 50% stenosis in ≥ 2 vessels, prior ischemic stroke/TIA/carotid stenosis ≥ 50%, DM, PAD, CrCl < 60)

Intervention: ticagrelor 180mg loading dose followed by 90mg BID + aspirin

Comparison: clopidogrel 300mg loading dose followed by 75mg daily + aspirin

Outcomes:
Primary: composite of death from vascular causes, MI, or CVA

Secondary

  • major bleeding (fatal bleeding, intracranial bleeding, intrapericardial bleeding w/ tamponade, hemorrhagic shock, decline of Hgb < 5.0, or requiring transfusion of 4 units pRBC)
  • all-cause mortality, MI, or stroke
  • composite of death from vascular mortality, MI, stroke, recurrent severe ischemia, recurrent ischemia, TIA, or other arterial thrombotic event
  • stent thrombosis

 

Results:
18,624 patients from 862 centers in 43 countries were recruited and enrolled in the study. 9,333 were randomized to the ticagrelor group, and 9291 were randomized to the clopidogrel group. Patients were followed for up to 12 months.

The two treatment groups did not statistically differ in baseline characteristics, non-study medications following randomization, or procedures following randomization. Both groups started the study drug at a median of 11.3 hours after the onset of chest pain.

The primary end point (death from vascular causes, MI, or CVA) occurred less often in the ticagrelor group than in the clopidogrel group – 9.8% vs 11.7% (HR 0.77 – 0.92; p < 0.001; NNT = 52.6).

The groups did not significantly differ in terms of major bleeding – 11.6% vs. 11.2% (HR 1.04; 95% CI 0.95 – 1.13; p = 0.43).

Patients who received ticagrelor trended toward an increased rate of intracranial bleeding (26 [0.3%] vs. 14 [0.2%], p = 0.06), including a statistically significant increase in fatal intracranial bleeding (11 [0.1%] vs. 1 [0.01%], p = 0.02) as well as non-CABG bleeding (4.5% vs. 3.8%, p = 0.03). However, there were fewer episodes of other types of fatal bleeding in the ticagrelor group.

Regarding other secondary outcomes, ticagrelor performed better in:

  • composite of all-cause, MI, or stroke – 10.2% vs. 12.3% (HR 0.84; 95% CI 0.77 – 0.92; p < 0.001; NNT 47.6)
  • composite of death from vascular causes, MI, stroke, severe recurrent ischemia, recurrent ischemia, TIA, or other arterial thrombotic event – 14.6% vs. 16.7% (HR 0.88; 95% CI 0.81 – 0.95; p < 0.001; NNT 47.6)
  • stent thrombosis – 1.3% vs. 1.9% (HR 0.67; 95% CI 0.50-0.91; p = 0.009, NNT = 167).

Dyspnea was more common in the ticagrelor group than in the clopidogrel group (13.8% vs 7.8%, p < 0.001). There was a higher incidence of ventricular pauses in the first week in the ticagrelor group relative to the clopidogrel group; however, the two groups did not differ in incidence of syncope or pacemaker implantation. Discontinuation of study drug due to adverse event was more common in the ticagrelor group (7.4% vs. 6.0%). Ticagrelor was also associated with elevations in uric acid and creatinine.

Implication/Discussion:
PLATO demonstrated that treatment of ACS with ticagrelor (vs. clopidogrel) significantly reduced the rate of death from vascular causes, MI, or stroke, without increasing the risk of major bleeding.

 Although ticagrelor patients did demonstrate higher rates of intracranial and non-CABG bleeding, this bleeding did not qualify as “major bleeding.” They also complained more frequently of dyspnea (a known adverse effect of the drug). Discontinuation of ticagrelor due to dyspnea occurred in 0.9% of patients. Due to this risk of dyspnea, as well as the risk of elevated serum uric acid and creatinine, caution should be used in those with a history of COPD, asthma, CHF, gout, and CKD who are considering using ticagrelor.

Strengths of this study include that it was a double-blind, randomized controlled trial with a large patient population. Weaknesses include that the study was funded by AstraZeneca, manufacturers of Brilinta (the brand name of ticagrelor). Also, the study drug did not perform as well in North American sites or underweight patients, yet the authors do not offer clear explanations as to why.

Bottom line:
Patients with a high risk of thrombosis and a low risk of bleeding may benefit most from ticagrelor. Ticagrelor has a mortality benefit when compared to clopidogrel. But ticagrelor should be used with caution in those with pulmonary disease (e.g. COPD or asthma), CKD, and heart block (due to association with ventricular pauses).

Drug cost: At time of study. Ticagrelor: $108/month; Clopidogrel: $26/month


Further Reading/References
:
1. Wiki Journal Club
2. 2 Minute Medicine
3. UpToDate, “Long-term antiplatelet therapy after coronary artery stenting in stable patients”
4. 2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients with Coronary Artery Disease

Summary by Patrick Miller, MD

Week 33 – CHOIR

“Correction of Anemia with Epoetin Alfa in Chronic Kidney Disease”

by the Investigators in the Correction of Hemoglobin and Outcomes in Renal Insufficiency (CHOIR)

N Engl J Med. 2006 Nov 16;355(20):2085-98. [free full text]

Anemia is a highly prevalent condition in CKD and ESRD. The anemia is largely attributable to the loss of erythropoietin production due to the destruction of kidney parenchyma. Thus erythropoiesis-stimulating agents (ESAs) were introduced to improve this condition. Retrospective data and small interventional trials suggested that treatment to higher hemoglobin goals (such as > 12g/dL) was associated with improved cardiovascular outcomes. However, a prospective trial in ESRD patients on HD with a hemocrit treatment target of 42% vs. 30% demonstrated a trend toward increased rates of non-fatal MI and death in the higher-target group. In an effort to clarify the hemoglobin goal in CKD patients, the 2006 CHOIR trial was designed. It was hypothesized that treatment of anemia in CKD to a target of 13.5g/dL would lead to fewer cardiac events and reduced mortality when compared to a target of 11.3g/dL.

Population: adults with CKD (eGFR 15-50ml/min) and Hgb < 11.0 g/dL

Notable exclusion criteria: active cancer, prior therapy with epo.

Patients who developed a requirement for dialysis were terminated from the study.

Intervention: target hemoglobin 13.5 g/dL with a regimen of epo support

Comparison: target hemoglobin 11.3 g/dL with a regimen of epo support

Outcome:

Primary – composite of death, MI, hospitalization for CHF, or stroke

Secondary:

  • each of the four components of the composite primary endpoint
  • need for renal replacement therapy
  • hospitalization for any cause
  • quality of life as measured by the Linear Analogue Self-Assessment (LASA), Kidney Disease Questionnaire (KDQ), and Medical Outcomes Study 36-item Short-Form Health Survey (SF-36)

 

Results:
This study was terminated early due to an interim analysis revealing a < 5% chance that there would be a demonstrated benefit for the high-hemoglobin group by the scheduled end of the study.

Results from 715 high-hemoglobin and 717 low-hemoglobin patients were analyzed.

Baseline characteristics were similar among the two groups aside from for higher rates of HTN (p=0.03) and CABG (p=0.05) in the high-hemoglobin group. Rates of iron supplementation during the study were similar among the two groups (~50%).

The mean change in hemoglobin was +2.5 g/dL in the high-hemoglobin group versus +1.2g/dL in the low-hemoglobin group (p<0.001).

The primary endpoint occurred in 125 of the high-hemoglobin patients (17.5%) versus 97 of the low-hemoglobin patients (13.5%) [HR 1.34, 95% CI 1.03-1.74, p=0.03; number needed to harm = 25].

There were no significant group differences among the four components of the primary endpoint when analyzed as individual secondary outcomes. Rates of renal replacement therapy (thus requiring termination from the study protocol) were 21.7% in the high-hemoglobin group versus 18.7% in the low-hemoglobin group (p=0.15). Any-cause hospitalization rates were 51.6% in the high-hemoglobin group versus 46.6% in the low-hemoglobin group (p=0.03).

Quality-of-life scores were assessed by the LASA, KDQ, and SF-36. Both groups demonstrated similar, statistically significant improvements from their respective baseline values, with the exception of a higher improvement in the emotional subset of SF-36 within the low-hemoglobin group.

The mean weekly dose of epoetin alfa required to maintain the target hemoglobin was 11,215 units/week in the high-hemoglobin group versus 6.276 units/week in the low-hemoglobin group.


Implication/Discussion
:
In patients with anemia and CKD, treatment to a higher hemoglobin goal of 13.5g/dL was associated with an increased incidence of a composite endpoint of death, MI, hospitalization for CHF, or stroke relative to a treatment goal of 11.3g/dL. The higher treatment goal also led to higher utilization of epoetin alfa. There were no differences between the two groups in hospitalization rates or progression to renal replacement therapy, and the improvement in quality of life was similar among the two treatment groups.

Thus this study demonstrated no additional benefit and some harm with the higher treatment goal.

The authors note that “this study did not provide a mechanistic explanation for the poorer outcome with the use of a high target hemoglobin level.”

Limitations of this trial included its non-blinded nature and relatively high patient withdrawal rates.

Following this trial, the KDOQI guidelines for the management of anemia in CKD were changed to state that “in dialysis and nondialysis patients with CKD receiving ESA therapy, the selected Hb target should generally be in the range of 11.0 to 12.0 g/dL.”

Expert opinion at UpToDate recommends administration of ESAs in iron-replete CKD and ESRD patients with Hgb < 10 g/dL with the goal of maintaining Hgb between 10 and 11.5 g/dL. Treatment should be individualized in patients with concurrent malignancy.


Further Reading/References
:
1. Wiki Journal Club
2. 2 Minute Medicine
3. KDOQI Clinical Practice Guideline and Clinical Practice Recommendations for Anemia in Chronic Kidney Disease: 2007 Update of Hemoglobin Target
4. Pfeffer et al. “A trial of darbepoetin alfa in type 2 diabetes and chronic kidney disease.” N Engl J Med. 2009;361(21):2019.
5. UpToDate, “Treatment of anemia in nondialysis chronic kidney disease”
6. UpToDate, “Treatment of anemia in hemodialysis patients”

Summary by Duncan F. Moore, MD

Week 32 – Rifaximin Treatment in Hepatic Encephalopathy

“Rifaximin Treatment in Hepatic Encephalopathy”

N Engl J Med. 2010 Mar25;362(12):1071-81. [free full text]

As we are well aware at Georgetown, hepatic encephalopathy (HE) is highly prevalent among patients with cirrhosis, and admissions for recurrent HE place a significant burden on the medical system. The authors of this study note that HE is thought to result from “the systemic accumulation of gut-derived neurotoxins, especially ammonia, in patients with impaired liver function and portosystemic shunting.” Lactulose is considered the standard of care for the prevention of HE. It is thought to decrease the absorption of ammonia in the gut lumen through its cathartic effects and by alteration of colonic pH. The minimally absorbable oral antibiotic rifaximin is thought to further reduce ammonia production through direct antibacterial effects within the gut lumen. Thus the authors of this pivotal 2010 study sought to determine the additive effect of daily rifaximin prophylaxis in the prevention of HE.

Population: adults with cirrhosis and 2+ episodes of overt HE during the past 6 months

Notable exclusion criteria: West Haven Criteria score of 2+ at enrollment, MELD score > 25, baseline Cr > 2.0, or if prior qualifying HE episodes were 2/2 GIB, medication effect, or renal failure

Intervention: rifaximin 550mg PO BID x6 months

Comparison: placebo 550mg PO BID x6 months

Outcomes:

Primary: time to first breakthrough episode of HE (West Haven Score of 2+ or West Haven Score 0 –> 1 with worsening asterixis)
Secondary

  • time to first hospitalization involving HE
  • adverse events, including those “possibly related to infection”

Results:
299 patients were randomized. 140 and 159 patients were assigned to rifaximin and placebo, respectively. Baseline characteristics were similar among the two groups. Lactulose use prior to and during the study was similar in both groups at approximately 91%.

Breakthrough HE occurred in 31 (22.1%) of the rifaximin patients and 73 (45.9%) of the placebo patients [HR 0.42, 95% CI 0.28-0.64, p<0.001, absolute risk reduction 23.7%, NNT = 4.2]. This result was consistent within all tested subgroups, except patients with MELD score 19-24 and patients who were not using lactulose at baseline (see Figure 3).

Hospitalization involving HE occurred in 19 (13.6%) of the rifaximin patients and 36 (22.6%) of the placebo patients [HR 0.50, 95% CI 0.29-0.87, p = 0.01, absolute risk reduction 9.1%, NNT = 11.0].

There were no differences in adverse events among the two treatment groups.

Implication/Discussion:
Prophylactic rifaximin reduced the incidence of recurrent hepatic encephalopathy and its resultant hospitalizations.

This landmark trial showed a clear treatment benefit with implied savings in healthcare utilization costs associated with HE recurrences and hospitalizations. This marked effect was demonstrated even in the setting of relatively good (91%) lactulose adherence in both treatment arms prior to and throughout the trial.

On the day this trial was published in 2010, the FDA approved rifaximin for “reduction in risk of overt hepatic encephalopathy recurrence” in adults.

Because rifaximin is not generic and remains quite expensive, its financial utility is limited from an insurance company’s perspective. There is no other comparable nonabsorbable antibiotic for this indication.

UpToDate suggests starting with lactulose therapy and then adding a nonabsorbable antibiotic, such as rifaximin, both for the treatment of overt hepatic encephalopathy and for the prevention of recurrent hepatic encephalopathy. In practice, most insurance companies will require a prior authorization for outpatient rifaximin treatment, but in my recent experience this process has been perfunctory and easy.

Further Reading/References:
1. ClinicalTrials.gov, NCT00298038
2. FDA, NDA approval letter for Xifaxan (rifaximin)

Summary by Duncan F. Moore, MD

Week 31 – Symptom-Triggered Benzodiazepines in Alcohol Withdrawal

“Symptom-Triggered vs Fixed-Schedule Doses of Benzodiazepine for Alcohol Withdrawal”

Arch Intern Med. 2002 May 27;162(10):1117-21. [free full text]

Treatment of alcohol withdrawal with benzodiazepines has been the standard of care for decades. However, in the 1990s, benzodiazepine therapy for alcohol withdrawal was generally given via fixed doses. In 1994, a double-blind RCT by Saitz et al. demonstrated that symptom-triggered therapy based on responses to the CIWA-Ar scale reduced treatment duration and the amount of benzodiazepine used relative to a fixed-schedule regimen. This trial had little immediate impact in the treatment of alcohol withdrawal. The authors of this 2002 double-blind RCT sought to confirm the findings from 1994 in a larger population that did not exclude patients with a history of seizures or severe alcohol withdrawal.

Population: consecutive patients admitted to the inpatient alcohol treatment units at two European universities

Notable exclusion criteria: “major cognitive, psychiatric, or medical comorbidity”

Intervention: placebo (30mg q6hrs x4, followed by 15mg q6hrs x8), with additional oxazepam 15mg for CIWA score 8-15 and 30mg for CIWA score > 15

Comparison: scheduled oxazepam (30mg q6hrs x4, followed by 15mg q6hrs x8), with additional oxazepam 15mg for CIWA score 8-15 and 30mg for CIWA score > 15

Outcomes:

Primary

  • cumulative oxazepam dose at 72hrs
  • oxazepam treatment duration

Secondary

  • incidence of seizures, hallucinations, and delirium tremens at 72hrs
  • subjective scales of “health concerns,” anxiety, depression, energy level, physical functioning, and vitality over the preceding 3 days, assessed at 72hrs

Subgroup analysis: exclusion of symptomatic patients who did not require any oxazepam

Results:
117 patients completed the trial. 56 had been randomized to the symptom-triggered group, and 61 had been randomized to the fixed-schedule group. The groups were similar in all baseline characteristics except that the fixed-schedule group had on average a 5-hour longer interval since last drink prior to admission. Only 39% of the symptom-triggered group actually received oxazepam, while 100% of the fixed-schedule group did (p < 0.001).

Patients in the symptom-triggered group received a mean cumulative dose of 37.5mg versus 231.4mg in the fixed-schedule group (p < 0.001). The mean duration of oxazepam treatment was 20.0 hours in the symptom-triggered group versus 62.7 hours in the fixed-schedule group.

The group difference in total oxazepam dose persisted even when patients who did not receive any oxazepam were excluded. Among patients who did receive oxazepam, patients in the symptom-triggered group received 95.4 ± 107.7mg versus 231.4 ± 29.4mg in the fixed-dose group (p < 0.001).

Only one patient in the symptom-triggered group sustained a seizure. There were no seizures, hallucinations, or episodes of delirium tremens in any of the other 116 patients. The two treatment groups had similar quality-of-life and symptom scores aside from slightly higher physical functioning in the symptom-triggered group (p < 0.01). See Table 2.


Implication/Discussion
:
Symptom-triggered administration of benzodiazepines in alcohol withdrawal led to a six-fold reduction in cumulative benzodiazepine use and a much shorter duration of pharmacotherapy than fixed-schedule administration. This more restrictive and responsive strategy did not increase the risk of major adverse outcomes such as seizure or DTs, and also did not result in increased patient discomfort.

Overall, this study confirmed the findings of the landmark study by Saitz et al. from eight years prior. Additionally, this trial was larger and did not exclude patients with a prior history of withdrawal seizures or severe withdrawal. The fact that both studies took place in inpatient specialty psychiatry units limits their generalizability to our inpatient general medicine populations.

Why the initial 1994 study did not gain clinical traction remains unclear. Both studies have been well-cited over the ensuing decades, and the paradigm has shifted firmly toward symptom-triggered benzodiazepine regimens using the CIWA scale. A 2010 Cochrane review cites the 1994 study only, while Wiki Journal Club and 2 Minute Medicine have entries on this 2002 study but not on the equally impressive 1994 study.

Further Reading/References:
1. “Individualized treatment for alcohol withdrawal. A randomized double-blind controlled trial.” JAMA. 1994.
2. Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar)
3. Wiki Journal Club
4. 2 Minute Medicine
5. “Benzodiazepines for alcohol withdrawal.” Cochrane Database Syst Rev. 2010.

Summary by Duncan F. Moore, MD

Week 30 – Omeprazole for Bleeding Peptic Ulcers

“Effect of Intravenous Omeprazole on Recurrent Bleeding After Endoscopic Treatment of Bleeding Peptic Ulcers”

N Engl J Med. 2000 Aug 3;343(5):310-6. [free full text]

Intravenous proton-pump inhibitor (PPI) therapy is a cornerstone of modern therapy for bleeding peptic ulcers. However, prior to this 2000 study by Lau et al., the role of PPIs in the prevention of recurrent bleeding after endoscopic treatment was unclear. At the time, re-bleeding rates after endoscopic treatment were noted to be approximately 15-20%. Although other studies had approached this question, no high-quality, large, blinded RCT had examined adjuvant PPI use immediately following endoscopic treatment.

Population: patients with bleeding gastroduodenal ulcer visualized on endoscopy in whom hemostasis was achieved following epinephrine injection and thermocoagulation (consecutive patients, single center in Hong Kong)

Intervention: omeprazole 80mg IV bolus followed by 8mg/hr infusion x72 hrs, followed by omeprazole 20mg PO x8 wks

Comparison: placebo bolus + drip x72 hrs, followed by omeprazole 20mg PO x8 wks

Outcome:
Primary – Recurrent bleeding within 30 days

Secondary

  1. Recurrent bleeding within 72 hrs
  2. Mean number of units of blood transfused within 30 days
  3. Duration of hospitalization
  4. All-cause mortality at 30 days


Results
:
120 patients were randomized to each arm. The two groups had similar baseline characteristics, including ulcer-specific characteristics. The trial was terminated early due to the finding on interim analysis of a significantly lower recurrent bleeding rate in the omeprazole arm.

Bleeding re-occurred within 30 days in 8 (6.7%) omeprazole patients versus 27 (22.5%) placebo patients (HR 3.9, 95% CI 1.7-9.0; NNT 6.3). A Cox proportional-hazards model, when adjusted for size and location of ulcers, presence/absence of coexisting illness, and history of ulcer disease, revealed a similar hazard ratio (HR 3.9, 95% CI 1.7-9.1).

Recurrent bleeding was most common during the first 72 hrs (4.2% of the omeprazole group versus 20% of the placebo group, RR 4.80, 95% CI 1.89-12.2, p<0.001). For a nice visualization of the early separation of re-bleeding rates, see the Kaplan-Meier curve in Figure 1.

The mean number of units of blood transfused within 30 days was 2.7 ± 2.5 in the omeprazole group versus 3.5 ± 3.8 in the placebo group (p = 0.04). The number of units transfused after the initial endoscopic treatment was 1.7 ± 1.9 in the omeprazole group versus 2.4 ± 3.2 in the placebo group (p = 0.03).

Regarding duration of hospitalization, 46.7% of omeprazole patients were admitted for < 5 days versus 31.7% of placebo patients (p = 0.02). Median stay was 4 days in the omeprazole group versus 5 days in the placebo group (p = 0.006).

4.2% of the omeprazole patients died within 30 days, whereas 10% of the placebo patients died (p = 0.13).

Implication/Discussion:
Treatment with intravenous omeprazole immediately following endoscopic intervention for bleeding peptic ulcer significantly reduced the rate of recurrent bleeding. This effect was most prominent within the first 3 days of therapy. This intervention also reduced blood transfusion requirements and shortened hospital stays.

The presumed mechanism of action is increased gastric pH facilitating platelet aggregation.

In 2018, the benefit of this intervention seems so obvious based on its description alone, that one would imagine that such a trial would not be funded or published in such a high-profile journal. However, the annals of medicine are littered with now-discarded interventions that made sense from a theoretical or mechanistic perspective but were demonstrated to be ineffective or even harmful (e.g. pharmacologic suppression of ventricular arrhythmias post-MI or renal denervation for refractory HTN).

Today, bleeding peptic ulcers are treated with an IV PPI twice daily. Per UpToDate, meta-analyses have not shown a benefit of continuous PPI infusion over this IV BID dosing. However, per 2012 guidelines in the American Journal of Gastroenterology, patients with active bleeding or non-bleeding visible vessels should receive both endoscopic intervention and IV PPI bolus followed by infusion.


Further Reading/References
:
1. Wiki Journal Club
2. 2 Minute Medicine
3. UpToDate, “Overview of the Treatment of Bleeding Peptic Ulcers”
4. Laine L, Jensen DM. “Management of patients with ulcer bleeding.” Am J Gastroenterol. 2012.

Summary by Duncan F. Moore, MD

Week 29 – ALLHAT

“Major Outcomes in High-Risk Hypertensive Patients Randomized to Angiotensin-Converting Enzyme Inhibitor or Calcium Channel Blocker vs. Diuretic”

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

JAMA. 2002 Dec 18;288(23):2981-97. [free full text]

Hypertension is a ubiquitous disease, and the cardiovascular and mortality benefits of BP control have been well described. However, as the number of available antihypertensive classes proliferated in the past several decades, a head-to-head comparison of different antihypertensive regimens was necessary to determine the optimal first-step therapy. The 2002 ALLHAT trial was a landmark trial in this effort.

Population:
33,357 patients aged 55 years or older with hypertension and at least one other coronary heart disease (CHD) risk factor (previous MI or stroke, LVH by ECG or echo, T2DM, current cigarette smoking, HDL < 35 mg/dL, or documentation of other atherosclerotic cardiovascular disease (CVD)). Notable exclusion criteria: history of hospitalization for CHF, history of treated symptomatic CHF, or known LVEF < 35%.

Intervention:
Prior antihypertensives were discontinued upon initiation of the study drug. Patients were randomized to one of three study drugs in a double-blind fashion. Study drugs and additional drugs were added in a step-wise fashion to achieve a goal BP <140/90 mmHg.

Step 1: titrate assigned study drug

  • chlorthalidone: 12.5 –> (sham titration) –> 25 mg/day
  • amlodipine: 2.5 –> 5 –> 10 mg/day
  • lisinopril: 10 –> 20 –> 40 mg/day

Step 2: add open-label agents at treating physician’s discretion (atenolol, clonidine, or reserpine)

  • atenolol: 25 to 100 mg/day
  • reserpine: 0.05 to 0.2 mg/day
  • clonidine: 0.1 to 0.3 mg BID

Step 3: add hydralazine 25 to 100 mg BID

Comparison:
Pairwise comparisons with respect to outcomes of chlorthalidone vs. either amlodipine or lisinopril. A doxazosin arm existed initially, but it was terminated early due to an excess of CV events, primarily driven by CHF.


Outcomes
:

Primary –  combined fatal CAD or nonfatal MI

Secondary

  • all-cause mortality
  • fatal and nonfatal stroke
  • combined CHD (primary outcome, PCI, or hospitalized angina)
  • combined CVD (CHD, stroke, non-hospitalized treated angina, CHF [fatal, hospitalized, or treated non-hospitalized], and PAD)

Results:
Over a mean follow-up period of 4.9 years, there was no difference between the groups in either the primary outcome or all-cause mortality.

When compared with chlorthalidone at 5 years, the amlodipine and lisinopril groups had significantly higher systolic blood pressures (by 0.8 mmHg and 2 mmHg, respectively). The amlodipine group had a lower diastolic blood pressure when compared to the chlorthalidone group (0.8 mmHg).

When comparing amlodipine to chlorthalidone for the pre-specified secondary outcomes, amlodipine was associated with an increased risk of heart failure (RR 1.38; 95% CI 1.25-1.52).

When comparing lisinopril to chlorthalidone for the pre-specified secondary outcomes, lisinopril was associated with an increased risk of stroke (RR 1.15; 95% CI 1.02-1.30), combined CVD (RR 1.10; 95% CI 1.05-1.16), and heart failure (RR 1.20; 95% CI 1.09-1.34). The increased risk of stroke was mostly driven by 3 subgroups: women (RR 1.22; 95% CI 1.01-1.46), blacks (RR 1.40; 95% CI 1.17-1.68), and non-diabetics (RR 1.23; 95% CI 1.05-1.44). The increased risk of CVD was statistically significant in all subgroups except in patients aged less than 65. The increased risk of heart failure was statistically significant in all subgroups.


Discussion
:
In patients with hypertension and one risk factor for CAD, chlorthalidone, lisinopril, and amlodipine performed similarly in reducing the risks of fatal CAD and nonfatal MI.

The study has several strengths: a large and diverse study population, a randomized, double-blind structure, and the rigorous evaluation of three of the most commonly prescribed “newer” classes of antihypertensives. Unfortunately, neither an ARB nor an aldosterone antagonist was included in the study. Additionally, the step-up therapies were not reflective of contemporary practice. (Instead, patients would likely be prescribed one or more of the primary study drugs.)

The ALLHAT study is one of the hallmark studies of hypertension and has played an important role in hypertension guidelines since it was published. Following the publication of ALLHAT, thiazide diuretics became widely used as first line drugs in the treatment of hypertension. The low cost of thiazides and their limited side-effect profile are particularly attractive class features. While ALLHAT looked specifically at chlorthalidone, in practice the positive findings were attributed to HCTZ, which has been more often prescribed. The authors of ALLHAT argued that the superiority of thiazides was likely a class effect, but according to the analysis at Wiki Journal Club, “there is little direct evidence that HCTZ specifically reduces the incidence of CVD among hypertensive individuals.” Furthermore, a 2006 study noted that that HCTZ has worse 24-hour BP control than chlorthalidone due to a shorter half-life. The ALLHAT authors note that “since a large proportion of participants required more than 1 drug to control their BP, it is reasonable to infer that a diuretic be included in all multi-drug regimens, if possible.” The 2017 ACC/AHA High Blood Pressure Guidelines state that, of the four thiazide diuretics on the market, chlorthalidone is preferred because of a prolonged half-life and trial-proven reduction of CVD (via the ALLHAT study).

Further Reading / References:
1. 2017 ACC Hypertension Guidelines
2. Wiki Journal Club
3. 2 Minute Medicine
4. Ernst et al, “Comparative antihypertensive effects of hydrochlorothiazide and chlorthalidone on ambulatory and office blood pressure.” (2006)
5. Gillis Pharmaceuticals: https://www.youtube.com/watch?v=HOxuAtehumc
6. Concepts in Hypertension, Volume 2 Issue 6

Summary by Ryan Commins, MD

Week 28 – SOLVD

“Effect of Enalapril on Survival in Patients with Reduced Left Ventricular Ejection Fractions and Congestive Heart Failure”

by the Studies of Left Ventricular Dysfunction (SOLVD) Investigators

N Engl J Med. 1991 Aug 1;325(5):293-302. [free full text]

Heart failure with reduced ejection fraction (HFrEF) is a very common and highly morbid condition. We now know that blockade of the renin-angiotensin-aldosterone system (RAAS) with an ACEi or ARB is a cornerstone of modern HFrEF treatment. The 1991 SOLVD trial played an integral part in demonstrating the benefit of and broadening the indication for RAAS blockade in HFrEF.

Population: patients with HFrEF and LVEF ≤ 35%, already on treatment, not on an ACEi, and Cr ≤ 2.0

Intervention: treatment with enalapril BID, starting at 2.5mg, uptitrated as tolerated to 20mg BID

Comparison: treatment with placebo BID, starting at 2.5mg, uptitrated as tolerated to 20mg BID

(There was a single-blind run-in period with enalapril in all patients, followed by a single-blind placebo run-in period. Finally, the patient was randomized to his/her actual study drug in a double-blind fashion.)

Outcome:

Primary

  1. All-cause mortality
  2. Death or hospitalization for CHF

Secondary

  1. Hospitalization for CHF
  2. All-cause hospitalization
  3. Cardiovascular mortality
  4. Heat failure mortality

 

Results:
2569 patients were enrolled. Baseline characteristics were similar among the two groups. Follow-up duration ranged from 22 to 55 months.

510 (39.7%) placebo patients died during follow-up compared to 452 (35.2%) enalapril patients (relative risk reduction of 16% per log-rank test, 95% CI 5-26% RRR, p = 0.0036). See Figure 1 for the relevant Kaplan-Meier curves.

736 (57.3%) placebo patients died or were hospitalized for CHF during follow-up compared to 613 (47.7%) enalapril patients (relative risk reduction 26%, 95% CI 18-34, p < 0.0001).

There were 971 hospitalizations for heart failure in the placebo group but only 683 in the enalapril group. (Many patients who ultimately died of CHF were hospitalized multiple times prior to death.) 950 placebo patients were hospitalized for any reason versus 893 enalapril patients (p = 0.006).

There were 461 cardiovascular deaths in the placebo group but only 399 in the enalapril group (relative risk reduction 18%, 95% CI 6-28%). There were 251 deaths due to heart failure in the placebo group, but only 209 in the enalapril group (relative risk reduction 22%, 95% CI 6-35%).

Regarding subgroup analysis, the authors point to Figure 4 and note that “the effects of enalapril were consistent among most…subgroups.”

320 placebo patients discontinued the study drug versus only 182 patients in the enalapril group. 82% of placebo patients and 87% of enalapril patients reported side effects. Enalapril patients were significantly more likely to report dizziness, fainting, and cough. There was no difference the prevalence of angioedema.


Implication/Discussion
:
Treatment of HFrEF with enalapril significantly reduced mortality and hospitalizations for heart failure. The authors note that for every 1000 study patients treated with enalapril, approximately 50 premature deaths and 350 heart failure hospitalizations are averted. The mortality benefit of enalapril appears to be immediate and increases for approximately 24 months.

Per the authors, “reductions in deaths and rates of hospitalization from worsening heart failure may be related to improvements in ejection fraction and exercise capacity, to a decrease in signs and symptoms of congestion, and also to the known mechanism of action of the agent – i.e., a decrease in preload and afterload when the conversion of angiotensin I to angiotensin II is blocked.”

Strengths of this study include its double-blind, randomized design, large sample size, and long follow-up. The fact that the run-in period allowed for the exclusion prior to randomization of patients who did not immediately tolerate enalapril is a major limitation of this study.

Prior to SOLVD, studies of ACEi in HFrEF had focused on patients with severe symptoms. The 1987 CONSENSUS trial was limited to patients with NYHA class IV symptoms. SOLVD broadened the indication of ACEi treatment to a wider group of symptoms and correlating EFs.

Per the current 2013 ACCF/AHA guidelines for the management of heart failure, ACEi/ARB therapy is a Class I recommendation in all patients with HFrEF in order to reduce morbidity and mortality.

Further Reading/References:
1. Wiki Journal Club
2. 2 Minute Medicine
3. Effects of enalapril on mortality in severe congestive heart failure – Results of the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS). 1987
4. 2013 ACCF/AHA guideline for the management of heart failure: executive summary

Summary by Duncan F. Moore, MD

Week 27 – UPLIFT

“A 4-Year Trial of Tiotropium in Chronic Obstructive Pulmonary Disease”

by the Understanding Potential Impacts on Function with Tiotropium (UPLIFT) investigators

N Engl J Med. 2008 October 9; 359(15):1543-1554 [free full text]

The 2008 UPLIFT trial was a four-year, randomized, double-blind, prospective study investigating whether or not tiotropium could reduce the rate of decline of FEV1 (a common metric for COPD progression).  A previous retrospective study had shown a reduced rate of FEV1 decline at one year with daily tiotropium. However, this finding had not been shown in any prospective study. As of 2008, smoking cessation was the only intervention demonstrated prospectively to decrease the rate of decline in FEV1.

Population:  Patients were selected from 490 investigational centers in 37 countries

Inclusion: COPD, age ≥ 40, ≥ 10 pack-year smoking history, post-bronchodilator FEV1 ≤70% of predicted value, and FEV1/FVC ≤70%

Exclusion: history of asthma, COPD exacerbation or respiratory infection within the past 4 weeks, history of pulmonary resection, or use of supplemental O2 for more than 12 hours per day

Intervention: daily tiotropium 18mcg + usual respiratory medications

Control: daily placebo + usual respiratory medications

(Of note, in both arms, the usual respiratory medications could not include an anticholinergic.)

Outcomes:

Co-primary:

  • Rate of decline in mean FEV1 before bronchodilation
  • Rate of decline in mean FEV1 after bronchodilation

Secondary:

  • Rate of decline in FVC
  • Quality of life as measured by St. George’s Respiratory Questionnaire (SGRQ, ranges 0-100 with lower scores indicating improved quality)
  • Rate of COPD exacerbations
  • All-cause mortality

Results:
2987 patients were assigned to receive tiotropium, and 3006 were assigned to receive placebo. Baseline characteristics were similar between the two groups. 44.6% of placebo and 36.2% of tiotropium patients did not complete at least 45 months of treatment.

The primary outcomes of decline in mean FEV1 either before or after bronchodilation were not significantly different between the two groups. Before bronchodilation, the difference in mean decline was 0 ml/year (p=0.95). After bronchodilation, the mean decline with tiotropium was 2 ml/year less than with placebo (p=0.21)

Regarding secondary outcomes:
There was no significant difference in rate of decline of FVC. The SGRQ was significantly lower (better) at all time points in the tiotropium group and, on average, was 2.7 points lower than in the placebo group (95% CI 2.0-3.3, p<0.001). The number of COPD exacerbations per year in the tiotropium group was 0.73 vs. 0.85 in the placebo group (RR 0.86, 95% CI 0.81-0.91; p<0.001), and the median time to first exacerbation was longer in the tiotropium group (16.7 months vs. 12.5 months, 95% CI 11.5-13.8,). All-cause mortality was not significantly different among the two groups (14.9% vs. 16.5%, HR 0.89; 95% CI 0.79-1.02; p=0.09). Respiratory failure developed in 88 patients in the tiotropium group vs. 120 in the placebo group (RR 0.67, 95% CI 0.51 to 0.89).

Discussion:
The UPLIFT study demonstrated no significant change in rate of decline in FEV1 with tiotropium therapy compared to placebo. However, tiotropium therapy improved quality of life and reduced the frequency of COPD exacerbations and respiratory failure. Overall, this study is an excellent example how a well-designed prospective study can overturn the results of prior retrospective analyses.

The authors offered three potential reasons for the lack of difference in rate of FEV1 decline among the groups. First, tiotropium may not actually alter the decline of lung function in COPD. Second, since both groups were permitted any respiratory medications other than another anticholinergic, there may have been a “ceiling effect” reached by the alternative medications, and thus no additional benefit offered by tiotropium therapy. Third, the authors noted the placebo group dropouts tended to be have more severe COPD, and so the remaining “healthy survivor” patients may have biased the group differences toward a null result.

Limitations of this study include a high dropout rate in both groups as well as a large male predominance (~75%) that limits generalizability. Finally, the limited clinical benefits of daily tiotropium use are not likely to be cost-effective. In 2010, researchers applied the treatment effects demonstrated in UPLIFT to an observational dataset of 56,321 tiotropium users in Belgium and estimated an average cost of 1.2 million euros per quality-adjusted life year (QALY) gained.

Further Reading/References:
1. Wiki Journal Club
2. 2 Minute Medicine
3. Neyt et al., “Tiotropium’s cost-effectiveness for the treatment of COPD: a cost-utility analysis under real-world conditions” (2010)

Summary by Gordon Pelegrin, MD

Week 26 – The Oregon Experiment

“The Oregon Experiment – Effects of Medicaid on Clinical Outcomes”

N Engl J Med. 2013 May 2;368(18):1713-22. [free full text]

Access to health insurance is not synonymous with access to healthcare. However, it has been generally assumed that increased access to insurance should improve healthcare outcomes among the newly insured. In 2008, Oregon expanded its Medicaid program by approximately 30,000 patients. These policies were lotteried among approximately 90,000 applicants. The authors of the Oregon Health Study Group sought to study the impact of this “randomized” intervention, the results of which were hotly anticipated given the impending Medicaid expansion of the 2010 PPACA.

Population: Portland, Oregon residents who applied for the 2008 Medicaid expansion

Not all applicants were actually eligible.

Eligibility criteria: age 19-64, US citizen, Oregon resident, ineligible for other public insurance, uninsured for the previous 6 months, income below 100% of the federal poverty level, and assets < $2000.

Intervention: winning the Medicaid-expansion lottery

Comparison: The statistical analyses of clinical outcomes in this study do not actually compare winners to non-winners. Instead, they compare non-winners to winners who ultimately received Medicaid coverage. Winning the lottery increased the chance of being enrolled in Medicaid by about 25 percentage points. Given the assumption that “the lottery affected outcomes only by changing Medicaid enrollment, the effect of being enrolled in Medicaid was simply about 4 times…as high as the effect of being able to apply for Medicaid.” This allowed the authors to conclude causal inferences regarding the benefits of new Medicaid coverage.

Outcomes: Values or point prevalence of the following at approximately 2 years post-lottery:

  1. blood pressure, diagnosis of hypertension
  2. cholesterol levels, diagnosis of hyperlipidemia
  3. HgbA1c, diagnosis of diabetes
  4. Framingham risk score for cardiovascular events
  5. positive depression screen, depression dx after lottery, antidepressant use
  6. health-related quality of life measures
  7. measures of financial hardship (e.g. catastrophic expenditures)
  8. measures of healthcare utilization (e.g. estimated total annual expenditure)

These outcomes were assessed via in-person interviews, assessment of blood pressure, and a blood draw for biomarkers.


Results
:
The study population included 10,405 lottery winners and 10,340 non-winners. Interviews were performed ~25 months after the lottery. While there were no significant differences in baseline characteristics among winners and non-winners, “the subgroup of lottery winners who ultimately enrolled in Medicaid was not comparable to the overall group of persons who did not win the lottery” (no demographic or other data provided).

At approximately 2 years following the lottery, there were no differences in blood pressure or prevalence of diagnosed hypertension between the lottery non-winners and those who enrolled in Medicaid. There were also no differences between the groups in cholesterol values, prevalence of diagnosis of hypercholesterolemia after the lottery, or use of medications for high cholesterol. While more Medicaid enrollees were diagnosed with diabetes after the lottery (absolute increase of 3.8 percentage points, 95% CI 1.93-5.73, p<0.001; prevalence 1.1% in non-winners) and were more likely to be using medications for diabetes than the non-winners (absolute increase of 5.43 percentage points, 95% CI 1.39-9.48, p=0.008), there was no statistically significant difference in HgbA1c values among the two groups. Medicaid coverage did not significantly alter 10-year Framingham cardiovascular event risk. At follow up, fewer Medicaid-enrolled patients screened positive for depression (decrease of 9.15 percentage points, 95% CI -16.70 to -1.60,  p=0.02), while more had formally been diagnosed with depression during the interval since the lottery (absolute increase of 3.81 percentage points, 95% CI 0.15-7.46, p=0.04). There was no significant difference in prevalence of antidepressant use.

Medicaid-enrolled patients were more likely to report that their health was the same or better since 1 year prior (increase of 7.84 percentage points, 95% CI 1.45-14.23, p=0.02). There were no significant differences in scores for quality of life related to physical health or in self-reported levels of pain or global happiness. As seen in Table 4, Medicaid enrollment was associated with decreased out-of-pocket spending (15% had a decrease, average decrease $215), decreased prevalence of medical debt, and a decreased prevalence of catastrophic expenditures (absolute decrease of 4.48 percentage points, 95% CI -8.26 to 0.69, p=0.02).

Medicaid-enrolled patients were prescribed more drugs and had more office visits but no change in number of ED visits or hospital admissions. Medicaid coverage was estimated to increase total annual medical spending by $1,172 per person (an approximately 35% increase). Of note, patients enrolled in Medicaid were more likely to have received a pap smear or mammogram during the study period.

Implication/Discussion:
This study was the first major study to “randomize” health insurance coverage and study the health outcome effects of gaining insurance.

Overall, this study demonstrated that obtaining Medicaid coverage “increased overall health care utilization, improved self-reported health, and reduced financial strain.” However, its effects on patient-level health outcomes were much more muted. Medicaid coverage did not impact the prevalence or severity of hypertension or hyperlipidemia. Medicaid coverage appeared to aid in the detection of diabetes mellitus and use of antihyperglycemics but did not affect average A1c. Accordingly, there was no significant difference in Framingham risk score among the two groups.

The glaring limitation of this study was that its statistical analyses compared two groups with unequal baseline characteristics, despite the purported “randomization” of the lottery. Effectively, by comparing Medicaid enrollees (and not all lottery winners) to the lottery non-winners, the authors failed to perform an intention-to-treat analysis. This design engendered significant confounding, and it is remarkable that the authors did not even attempt to report baseline characteristics among the final two groups, let alone control for any such differences in their final analyses. Furthermore, the fact that not all reported analyses were pre-specified raises suspicion of post hoc data dredging for statistically significant results (“p-hacking”). Overall, power was limited in this study due to the low prevalence of the conditions studied.

Contemporary analysis of this study, both within medicine and within the political sphere, was widely divergent. Medicaid-expansion proponents noted that new access to Medicaid provided a critical financial buffer from potentially catastrophic medical expenditures and allowed increased access to care (as measured by clinic visits, medication use, etc.), while detractors noted that, despite this costly program expansion and fine-toothed analysis, little hard-outcome benefit was realized during the (admittedly limited) follow-up at two years.

Access to insurance is only the starting point in improving the health of the poor. The authors note that “the effects of Medicaid coverage may be limited by the multiple sources of slippage…[including] access to care, diagnosis of underlying conditions, prescription of appropriate medications, compliance with recommendations, and effectiveness of treatment in improving health.”

Further Reading/References:
1. Baicker et al. (2013), “The Impact of Medicaid on Labor Force Activity and Program Participation: Evidence from the Oregon Health Insurance Experiment”
2. Taubman et al. (2014), “Medicaid Increases Emergency-Department Use: Evidence from Oregon’s Health Insurance Experiment”
3. The Washington Post, “Here’s what the Oregon Medicaid study really said” (2013)
4. Michael Cannon, “Oregon Study Throws a Stop Sign in Front of ObamaCare’s Medicaid Expansion”
5. HealthAffairs Policy Brief, “The Oregon Health Insurance Experiment”
6. The Oregon Health Insurance Experiment
7. Sommers et al. (2017) “Health Insurance Coverage and Health – What the Recent Evidence Tells Us

Summary by Duncan F. Moore, MD

Week 25 – CLOT

“Low-Molecular-Weight Heparin versus a Coumarin for the Prevention of Recurrent Venous Thromboembolism in Patients with Cancer”

by the Randomized Comparison of Low-Molecular-Weight Heparin versus Oral Anticoagulant Therapy for the Prevention of Recurrent Venous Thromboembolism in Patients with Cancer (CLOT) Investigators

N Engl J Med. 2003 Jul 10;349(2):146-53. [free full text]

Malignancy is a pro-thrombotic state, and patients with cancer are at significant and sustained risk of venous thromboembolism (VTE) even when treated with warfarin. Warfarin is a suboptimal drug that requires careful monitoring, and its effective administration is challenging in the setting of cancer-associated difficulties with oral intake, end-organ dysfunction, and drug interactions. The 2003 CLOT trial was designed to evaluate whether treatment with low-molecular-weight heparin (LMWH) was superior to a vitamin K antagonist (VKA) in the prevention of recurrent VTE.

Population: adults with active cancer and newly diagnosed symptomatic DVT or PE

The cancer must have been diagnosed or treated within past 6 months, or the patient must have recurrent or metastatic disease.

Intervention: dalteparin subQ daily (200 IU/kg daily x1 month, then 150 IU/kg daily x5 months)

Comparison: vitamin K antagonist x6 months (with 5-7 day LMWH bridge), target INR 2.5

Outcomes:

primary = recurrence of symptomatic DVT or PE within 6 months follow-up

secondary = major bleeding, any bleeding, all-cause mortality

 

Results:
338 patients were randomized to the LMWH group, and 338 were randomized to the VKA group. Baseline characteristics were similar among the two groups. 90% of patients had solid malignancies, and 67% of patients had metastatic disease. Within the VKA group, INR was estimated to be therapeutic 46% of the time, subtherapeutic 30% of the time, and supratherapeutic 24% of the time.

Within the six-month follow-up period, symptomatic VTE occurred in 8.0% of the dalteparin group and 15.8% of the VKA group (HR 0.48, 95% CI 0.30-0.77, p=0.002; NNT = 12.9). The Kaplan-Meier estimate of recurrent VTE at 6 months was 9% in the dalteparin group and 17% in the VKA group.

6% of the dalteparin group developed major bleeding versus 6% of the VKA group (p = 0.27). 14% of the dalteparin group sustained any type of bleeding event versus 19% of the VKA group (p = 0.09). Mortality at 6 months was 39% in the dalteparin group versus 41% in the VKA group (p = 0.53).

Implication/Discussion:
Treatment of VTE in cancer patients with low-molecular-weight heparin reduced the incidence of recurrent VTE relative to the incidence following treatment with vitamin K antagonists.

Notably, this reduction in VTE recurrence was not associated with a change in bleeding risk. However, it also did not correlate with a mortality benefit either.

This trial initiated a paradigm shift in the treatment of VTE in cancer. LMWH became the standard of care, although access and adherence to this treatment was thought to be limited by cost and convenience.

Until last week, no trial had directly compared a DOAC to LMWH in the prevention of recurrent VTE in malignancy. In an open-label, noninferiority trial, the Hokusai VTE Cancer Investigators demonstrated that the oral Xa inhibitor edoxaban (Savaysa) was noninferior to dalteparin with respect to a composite outcome of recurrent VTE or major bleeding.

Further Reading/References:
1. Wiki Journal Club
2. 2 Minute Medicine
3. UpToDate, “Treatment of venous thromboembolism in patients with malignancy”
4. “Edoxaban for the Treatment of Cancer-Associated Venous Thromboembolism,” NEJM 2017

Summary by Duncan F. Moore, MD