Medical treatment for chronic aortic regurgitation: β-blockers-maybe not bad, but good?

摘要

Chronic aortic regurgitation (AR) results in left ventricular (LV) volume overload, leading to progressive dilation of the chamber and eventual deterioration in LV function. Vasodilator therapy has been used to reduce regurgitant volume, after-load, LV volumes, and wall stress in an effort to preserve LV function and reduce LV mass. Early studies demonstrated a favourable acute effect of vasodilators in reducing regurgitant volume and improving cardiac function in AR. At least 10 prospective randomised clinical trials evaluated this form of ambulatory therapy in asymptomatic patients with chronic moderate-severe AR and normal LV function. While most studies demonstrated favourable effects of ACE inhibitors, nifedipine and hydralazine on some haemodynamic and/or structural parameters, other studies did not. Scognamiglio et al reported that nifedipine reduced or delayed the need for valve replacement in a large series of patients followed for an average of 6 years. However, an important limitation of their study was that digoxin was used in the control group. Our group failed to demonstrate a superior effect of nifedipine or enalapril compared with placebo on the delay in aortic valve replacement indication in a series of 130 patients followed for 7 years. As a consequence of previous results, the American Heart Association/American College of Cardiology guideline changed the class Ⅰ recommendation on vasodilator treatment for all asymptomatic patients with chronic severe AR to treating only patients with systolic blood pressure ＞ 140 mm Hg.