dal-OUTCOMESEffects of Dalcetrapib in Patients with a Recent Acute Coronary Syndrome
Background In observational analyses, higher levels of high-density lipoprotein (HDL) cholesterol
have been associated with a lower risk of coronary heart disease events. However,
whether raising HDL cholesterol levels therapeutically reduces cardiovascular
risk remains uncertain. Inhibition of cholesteryl ester transfer protein (CETP) raises
HDL cholesterol levels and might therefore improve cardiovascular outcomes. Methods We randomly assigned 15,871 patients who had had a recent acute coronary syndrome
to receive the CETP inhibitor dalcetrapib, at a dose of 600 mg daily, or placebo,
in addition to the best available evidence-based care. The primary efficacy end point
was a composite of death from coronary heart disease, nonfatal myocardial infarction,
ischemic stroke, unstable angina, or cardiac arrest with resuscitation. Results At the time of randomization, the mean HDL cholesterol level was 42 mg per deciliter
(1.1 mmol per liter), and the mean low-density lipoprotein (LDL) cholesterol
level was 76 mg per deciliter (2.0 mmol per liter). Over the course of the trial, HDL
cholesterol levels increased from baseline by 4 to 11% in the placebo group and by
31 to 40% in the dalcetrapib group. Dalcetrapib had a minimal effect on LDL cholesterol
levels. Patients were followed for a median of 31 months. At a prespecified
interim analysis that included 1135 primary end-point events (71% of the projected
total number), the independent data and safety monitoring board recommended
termination of the trial for futility. As compared with placebo, dalcetrapib did not
alter the risk of the primary end point (cumulative event rate, 8.0% and 8.3%, respectively;
hazard ratio with dalcetrapib, 1.04; 95% confidence interval, 0.93 to
1.16; P = 0.52) and did not have a significant effect on any component of the primary
end point or total mortality. The median C-reactive protein level was 0.2 mg
per liter higher and the mean systolic blood pressure was 0.6 mm Hg higher with
dalcetrapib as compared with placebo (P<0.001 for both comparisons). Conclusions In patients who had had a recent acute coronary syndrome, dalcetrapib increased
HDL cholesterol levels but did not reduce the risk of recurrent cardiovascular events.