Carvedilol versus verapamil in chronic stable angina: a multicentre trial

In a multicentre, double-blind, parallel group study, the anti-anginal and the anti-ischaemic efficacy of 12 weeks of therapy with the vasodilating beta-adrenoceptor-blocker carvedilol 25 mg b.i.d. was compared with verapamil 120 mg t.i.d.

During a 2-week placebo run-in period, patients were required to have two treadmill exercise tests (modified Bruce Protocol) differing by not more than 15% with regard to total exercise time (TET). Of 313 patients enrolled, 248 were randomized and 212 completed the study according to the protocol.

The primary variable TET was analysed using the Cox Proportional Hazards Model to take into account censored values due to the patient stopping the exercise test for reasons other than angina. Forty-three per cent of patients allocated to carvedilol and 36% to verapamil did not stop with angina at the final visit. There was no difference in the TET between the groups, the risk ratio being 1.14 in favour of carvedilol (90% CI 0.85-1.52). TET increased from 378 s at baseline to 436 s at the final visit in the carvedilol group and from 386 to 438 s in the verapamil group. Results for time to angina and time to 1 mm ST-segment depression were similar. Compared to verapamil, carvedilol significantly reduced HR, systolic BP and rate pressure product at peak exercise. Analysis of 48 h Holter monitor data showed a greater reduction of HR and PVCs with carvedilol. Lown grading improved in both groups. Adverse events were reported by 48% (3.2% serious adverse events) of patients taking carvedilol and 58% (5.7% serious adverse events) taking verapamil.

Carvedilol is at least as effective as verapamil in the management of chronic stable angina and demonstrated a favourable adverse event profile.