my personal edition > hypertension > news


  E-Mail this DGReview to a colleague

DGReview

Calcium Blockers Not Better Than Other Drug Classes

Calcium antagonists are about as effective as diuretics and beta-blockers in reducing cardiovascular disease, but they are not better, according to a 3-year study.

The Controlled ONset Verapamil INvestigation of Cardiovascular Endpoints (CONVINCE) trial, which involved 16,602 patients at 661 centres in 15 countries, "did not demonstrate equivalence of a controlled-onset extended-release verapamil-based anti-hypertensive regimen compared with a regimen beginning with a diuretic or beta-blocker", researchers reported.

Members of the CONVINCE Research group, based at Rush Medical College of Rush University, in Chicago, Illinois, said their conclusion about the relative efficacy of the three drug classes should be seen "in the context of other trials of calcium antagonists".

They observed that although hypertensive patients were often given calcium antagonists to reduce cardiovascular risk, the benefit compared to other drug classes was still controversial.

To see if initial therapy with the controlled-onset extended-release calcium antagonist verapamil was equivalent to a physician's choice of the beta-blocker atenolol or the diuretic hydrochlorothiazide in preventing cardiovascular disease, they conducted the double-blind, randomised clinical CONVINCE trial.

The participants, diagnosed as having hypertension, also had one or more additional risk factors for cardiovascular disease. They were enrolled between September 1996 and December 1998, and were followed up until the end of 2000.

Initially, 8,241 participants received controlled-onset extended-release verapamil 180 mg. and 8,361 participants received either atenolol 50 mg or hydrochlorothiazide 12.5 mg. Other drugs, such as diuretics, beta-blockers or angiotensin-converting enzyme inhibitors, could be added in specified sequence if needed.

Systolic blood pressure in verapamil recipients fell by 13.6 mm Hg and diastolic blood pressure by 7.8 mm Hg.

Systolic blood pressure in the atenolol and hydrochlorothiazide recipients fell by 13.5 mm Hg and diastolic blood pressure by 7.1 mm Hg.

With verapamil, there were 364 primary cardiovascular disease-related events and with the other two agents there were 365.

The risks associated with verapamil and the other two agents differed only marginally for both fatal and non-fatal strokes and myocardial infarctions, for cardiovascular disease-related death, for any pre-specified cardiovascular disease-related event and for all-cause mortality.

Non-stroke haemorrhages occurred significantly more often with verapamil, affecting 118 recipients, compared with 79 recipients of atenolol or hydrochlorothiazide.

With all three agents, there were more events related to cardiovascular disease between 6.00 AM and noon than at other times.
JAMA 2003;289:16:2073-2082. "Principal Results of the Controlled Onset Verapamil Investigation of Cardiovascular End Points (CONVINCE) Trial"

E-Mail this DGReview to a colleague

To print, use this version