Randomised, double-blind trial of intravenous diltiazem versus glyceryl trinitrate for unstable angina pectoris

The effect of dihydropyridines in patients with unstable angina is discouraging. To find out the effect of the non-dihydropyridine-like calcium-channel blocker diltiazem, a randomised, double-blind trial was conducted comparing diltiazem with glyceryl trinitrate, both given intravenously, in 129 patients with unstable angina. The endpoints were refractory angina or myocardial infarction, individually and as a composite endpoint. Refractory angina alone or together with myocardial infarction occurred significantly less commonly in the diltiazem group. While patients were on the trial drugs the numbers with refractory angina were 6 (10%) in the diltiazem group versus 17 (28%) in the glyceryl trinitrate group (relative risk 0·36, P=0·02), and the numbers with refractory angina and myocardial infarction were 9 (15%) versus 23 (38%) (relative risk 0·40, P=0·007). Over 48 h the numbers were: refractory angina 8 (13%) versus 18 (30%), relative risk 0·45, P=0·03, and refractory angina and myocardial infarction 12 (20·0%) versus 25 (41%),