The Effects of Calcium Channel Blockers on Cardiovascular Outcomes: a Review of Randomised Controlled Trials

Abstract

The choice of antihypertensive treatment should be guided by evidence of a reduction in the risk of cardiovascular (CV) events and therefore improved long-term outcome. Using pre-determined criteria, ten randomised, controlled trials that assessed the effects of calcium channel blockers (CCBs) on CV events in patients with hypertension were identified. Six of them enrolled a relatively small number (<1500) of hypertensive patients, whereas four of the studies were much larger (>4500 patients). The smaller studies produced mixed findings, especially those trials where CCBs were compared with diuretics; this may reflect methodological limitations and the impact of random error. The results from the four larger studies produced a consistent message: long-acting CCBs such as nifedipine, administered in a gastro-intestinal-transport-system (GITS) formulation, nitrendipine and diltiazem, reduce CV morbidity and mortality in hypertensive patients. In the one study that specifically enrolled high-risk hypertensive patients, nifedipine GITS was as effective as diuretic therapy in reducing CV events, and in all four larger studies sub-group analyses showed that the benefits of these CCBs extend to hypertensive patients with diabetes. The available evidence supports the use of these long-acting CCBs as a first-line treatment option in hypertensive patients.