The role of calcium antagonists in stroke prevention.

Lowering elevated blood pressure significantly reduces the risk of stroke, but whether any specific type of antihypertensive medication is better for this purpose, independent of blood pressure-lowering effects, is controversial. Compared with placebo or no treatment, the point estimate for stroke reduction is the largest with calcium antagonists; all such studies used dihydropyridine compounds. When all clinical trials published through December 2004 are combined in meta-analysis, stroke is not significantly reduced when an initial dihydropyridine or nondihydropyridine calcium antagonist is compared with an initial diuretic or beta blocker, but when the two subclasses are combined, stroke reduction (9%) is significant. The risk of heart failure, however, is significantly increased (by 29%) with the initial calcium antagonist. These estimates may change as newer trials are reported.