Therapeutic window for calcium-channel blockers in the management of dilated cardiomyopathy: a prospective, two-centre study on non-advanced disease.

OBJECTIVE

This study aimed to investigate the usefulness of the calcium-channel blocker verapamil in non-advanced dilated cardiomyopathy (DCM).

METHODS

This was a randomised trial of 70 DCM patients treated with carvedilol (36 patients) and verapamil (instead of β-blocker; 34 patients) for 12 months. The remaining heart failure (HF) therapy was constant in both groups. The primary outcomes were to determine selected echocardiography parameters and functional status of patients. The secondary outcome included death, heart transplantation and re-hospitalisation due to HF progression.

RESULTS

Of the primary outcomes, only the mean ratio of early to late transmitral flow velocities increased significantly in the verapamil-treated patients as compared with the carvedilol-based therapy (1.1 ± 0.3 vs. 0.7 ± 0.2; 95% CI -0.6 to -0.1; p = 0.015). Simultaneously, the Minnesota Quality of Life improved significantly in the verapamil group (95% CI 5.2-19.9; p = 0.002). It was accompanied by the favourable effect of verapamil therapy on exercise capacity in the 6-min walk test (95% CI 21.3-110.7; p = 0.005).

CONCLUSION

The addition of verapamil to angiotensin-converting enzyme and aldosterone inhibitors in non-advanced DCM patients has been shown to have a neutral or even positive effect in a few patients.