Short- and long-term responses to diltiazem in patients with variant angina

Short- and long-term effects of diltiazem on angina frequency were studied in 12 patients with variant angina (pain at rest with S-T elevation). Each patient first entered a double-blind short-term trial. Either diltiazem, in two dosage schedules (120 and 240 mg/day), or placebo was administered in a randomized double-blind program over 10 weeks. Significant decreases in frequency of angina were observed when diltiazem treatment periods were compared with placebo periods. Six patients were asymptomatic, one had 50 percent or greater decrease, and two had a smaller decrease in angina frequency. Two patients showed no important improvement during short-term diltiazem therapy. One patient experienced ventricular fibrillation in the placebo period and was advanced to treatment with open label diltiazem before responses could be ascertained in the double-blind trial. All other patients were then advanced to open label diltiazem therapy and followed up for an average of 16 months (range 8 to 23). Responses during the short-term trial accurately predicted responses during long-term therapy. Of the six patients who were asymptomatic during short-term therapy, five remained asymptomatic and one had rare episodes of angina. One other patient continued to have a good response (50 percent or greater decrease in angina frequency) and two other patients had a partial response. The two patients who did not respond during short-term therapy did not respond during long-term therapy.