Long-term antianginal and antiischemic effects of mibefradil, the novel T-type calcium channel blocker: a multicenter, double-blind, placebo-controlled, randomized comparison with sustained-release diltiazem.

This study compared the efficacy, safety, and tolerability of mibefradil to sustained-release diltiazem in patients with chronic stable angina pectoris. At week 12, statistically equivalent mean increases in exercise tolerance test (ETT) duration of > 1 minute were observed in both groups. Similar improvements in time to onset of angina and time to persistent 1 mm ST-segment depression were also observed with both drugs. Large reductions in heart rate, blood pressure, and rate-pressure product were observed at each stage of the ETT among patients treated with mibefradil. Each drug was associated with at least a 70% reduction from baseline in anginal frequency and nitroglycerin consumption. Patients maintained on mibefradil during the withdrawal period had significant increases in all three ETT variables at week 16 compared with placebo. The effectiveness of mibefradil is comparable with sustained-release diltiazem in treating chronic stable angina pectoris, although mibefradil provides greater reductions in heart rate and cardiac workload.