Early treatment of unstable angina with nifedipine and metoprolol--the HINT trial

A multicenter, double-blind, placebo-controlled, randomized trial of nifedipine, metoprolol, and their combination was conducted in a group of 338 patients with unstable angina not pretreated with a beta-blocker and of nifedipine in 177 patients who were. The main outcome event was recurrent ischemia or myocardial infarction within 48 h. Trial medication effects were expressed as ratios of event rates relative to placebo. In patients not pretreated with a beta-blocker, the event rate ratios with associated 95% confidence intervals were 1.15 (0.83, 1.64) for nifedipine, 0.76 (0.49, 1.16) for metoprolol, and 0.80 (0.53, 1.19) for the combination. In patients already on a beta-blocker, the addition of nifedipine was beneficial [rate ratio of 0.68 (0.47, 0.97)]. Equal numbers of patients developed myocardial infarction and reversible ischemia. Most infarctions occurred early, within 6 h of randomization. These results suggest that in patients not on prior beta-blockade, metoprolol has a beneficial short-term effect on unstable angina, the fixed combination with nifedipine provides no further gain, and nifedipine may be counterproductive. On the other hand, the addition of nifedipine to existing beta-blockade when the patient becomes unstable seems beneficial. These findings accord with those of other trials on unstable angina