The ezetimibe controversy – can this be resolved by comparing the clinical trials with simvastatin and ezetimibe alone and together?

Clinical efficacy and safety of Ezetimibe on major cardiovascular endpoints: systematic review and meta-analysis of randomized controlled trials

Background

Randomized clinical trials (RCTs) about Ezetimibe's efficacy on patient-oriented outcomes have given discordant results. The aim of this study was to determine the net effect of Ezetimibe and of the widely marketed combination, Ezetimibe+simvastatin, on mortality and morbidity outcomes.

Methods and Findings

We searched for RCT on Ezetimibe using MEDLINE, CCTR, EMBASE, ClinicalTrials.gov databases up to December 2013, Merck and Novartis online registers, and personal communications. Two authors independently selected trials fulfilling these criteria: RCTs comparing Ezetimibe±statin or another lipid-lowering drug against placebo, or against the same lipid-lowering drug at the same dosage, with a follow-up at least 24 weeks and one or more of these outcomes: all-cause mortality, cardiovascular (CV) mortality, stroke, myocardial infarction (MI), cancer, serious adverse events (SAEs); we assessed the risk of bias using the Cochrane checklist. We extracted the data for major clinical events as a dichotomous measure, with the patient the unit of analysis. Pooled analysis was done with random and fixed effect based models. Trials comparing Ezetimibe plus a lipid-lowering drug against the same lipidlowering drug representing the net effect of Ezetimibe, showed a nonsignificant tendency toward damage for cancer, MI, stroke and SAEs. Ezetimibe+simvastatin vs. simvastatin alone showed a stronger tendency towards a higher risk for all-cause death (2.52; 0.65-9.74), CV death (3.04; 0.48-19.21), non-CV death (3.03; 0.12-73.50), MI (1.91; 0.42-8.70), stroke (2.38; 0.46-12.35), cancer (RR 11.11; 0.62-198.29), and SAEs (1.45; 0.95-2.23). Limitations include small numbers of events and inadequate power of the pooling. Trials comparing Ezetimibe+simvastatin vs placebo showed non-significant effects: MI (0.81; 0.66-1.00 p = 0.051), all-cause death (1.02; 0.95-1.09), CV death (0.91; 0.80-1.04), non-CV death (108; 0.99-1.18), stroke (0.86; 0.72-1.04), cancer (1.18; 0.80-1.74), SAEs (1.01; 0.96-1.06).

Conclusions

Ezetimibe±simvastatin had inconsistent effects on important outcomes. No firm conclusions are possible, but findings indicative of damage suggest much more selective use of Ezetimibe±simvastatin.

Management and outcomes of patients with reduced ejection fraction after acute myocardial infarction in cardiac rehabilitation centers

BACKGROUND

We aimed to describe the contemporary management of patients with systolic chronic heart failure (CHF) during a cardiac rehabilitation (CR) stay and present outcomes with focus on lipids, blood pressure, exercise capacity, and clinical events.

METHODS

Comparison of 3199 patients with moderately or severely impaired left ventricular ejection fraction (low EF, 13.3%) and 20,913 patients with slightly reduced or normal LVEF (normal EF, 86.7%) who underwent an inpatient CR period of about 3 weeks in 2009-2010.

RESULTS

Patients with low EF compared to those with normal EF were somewhat older (65.1 vs. 63.0 years, p < 0.0001), and more often had risk factors such as diabetes mellitus (39.7% vs. 32.0%, p < 0.0001) or other comorbidities. The overall rate of patients with regular physical activity of at least 90 minutes per week prior to CR was low overall (54.4%), and reduced in patients with low EF compared to those with normal EF (47.7% vs. 55.5%, p < 0.0001). The rate of patients that achieved lower LDL cholesterol (<100 mg/dl), total cholesterol (<200 mg/dl) and triglyceride (<150 mg/dl) values at discharge increased compared to baseline. Mean blood pressure was substantially lower in the low EF group compared to the normal EF group both at baseline (124/75 vs. 130/78 mmHg, p < 0.0001) and at discharge (119/72 vs. 124/74 mmHg, p < 0.0001). Maximum exercise improved substantially in both groups (at baseline 71 vs. 91 Watts, p < 0.0001; at discharge 85 vs. 105 Watts, p < 0.0001). Event rates during CR were low, and only 0.3% in the low EF group died. As limitations to this study, information on brain natriuretic peptide (BNP), N-terminal pro-brain natriuretic peptide (NT-pro BNP) and/or cardiac troponin were not documented, and no long-term information was collected beyond the 3-week CR stay.

CONCLUSIONS

Patients with CHF account for a considerable proportion of patients in CR. Also patients with moderate/severe EF benefited from participation in CR, as their lipid profile and physical fitness improved.

How good is "evidence" from clinical studies of drug effects and why might such evidence fail in the prediction of the clinical utility of drugs?

Promising evidence from clinical studies of drug effects does not always translate to improvements in patient outcomes. In this review, we discuss why early evidence is often ill suited to the task of predicting the clinical utility of drugs. The current gap between initially described drug effects and their subsequent clinical utility results from deficits in the design, conduct, analysis, reporting, and synthesis of clinical studies-often creating conditions that generate favorable, but ultimately incorrect, conclusions regarding drug effects. There are potential solutions that could improve the relevance of clinical evidence in predicting the real-world effectiveness of drugs. What is needed is a new emphasis on clinical utility, with nonconflicted entities playing a greater role in the generation, synthesis, and interpretation of clinical evidence. Clinical studies should adopt strong design features, reflect clinical practice, and evaluate outcomes and comparisons that are meaningful to patients. Transformative changes to the research agenda may generate more meaningful and accurate evidence on drug effects to guide clinical decision making.

Review of the cost effectiveness of pharmacogenetic-guided treatment of hypercholesterolaemia

Hypercholesterolaemia is a highly prevalent condition that has major health and cost implications for society. Pharmacotherapy is an important and effective treatment modality for hypercholesterolaemia, with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ('statins') the most commonly used class of drugs. Over the past decade, there has been intensive research to identify pharmacogenetic markers to guide treatment of hypercholesterolaemia. This study aimed to review the evidence of incremental cost, effect and cost effectiveness of pharmacogenetic-guided treatment of hypercholesterolaemia. Three cost-effectiveness analyses (CEAs) were identified that studied the value of screening for genotypes of angiotensin I converting enzyme (ACE), cholesteryl ester transfer protein (CETP), and kinesin family member 6 (KIF6) prior to initiating statin therapy. For all three CEAs, a major limitation identified was the reproducibility of the evidence supporting the clinical effect of screening for the pharmacogenetic marker. Associated issues included the uncertain value of pharmacogenetic markers over or in addition to existing approaches for monitoring lipid levels, and the lack of evidence to assess the effectiveness of alternative therapeutic options for individuals identified as poor responders to statin therapy. Finally, the economic context of the market for diagnostic tests (is it competitive or is there market power?) and the practicality of large-scale screening programmes to inform prescribing in a complex and varied market may limit the generalizability of the results of the specific CEAs to policy outcomes. The genotype of solute carrier organic anion transporter family member 1B1 (SLCO1B1) has recently been associated with increased risk of muscle toxicity with statin therapy and the review identified that exploration of cost effectiveness of this pharmacogenetic marker is likely warranted.