Vasodilator therapy in chronic asymptomatic aortic regurgitation: enalapril versus hydralazine therapy

J Am Coll Cardiol. 1994 Oct;24(4):1046-53. doi: 10.1016/0735-1097(94)90868-0.


Objectives: This study attempted to evaluate the long-term efficacy of enalapril versus hydralazine therapy on left ventricular volume, mass and function as well as on the renin-angiotensin system in chronic asymptomatic aortic regurgitation.

Background: We tested the hypothesis that early administration of a vasodilator drug might be able to reduce left ventricular dilation and mass expansion. Because the renin-angiotensin system may be activated in chronic aortic regurgitation, early enalapril therapy might be beneficial.

Methods: Between 1990 and 1993, 76 asymptomatic nonrheumatic patients with mild to severe chronic aortic regurgitation were enrolled in a randomized, double-blind trial comparing enalapril with hydralazine. All patients underwent serial noninvasive studies. Seventy patients completed the 12-month follow-up.

Results: At 1 year, patients receiving enalapril had a significant reduction in left ventricular end-diastolic and end-systolic volume indexes (124 +/- 15 vs. 108 +/- 17 ml/m2, p < 0.01; 50 +/- 12 vs. 40 +/- 14 ml/m2, p < 0.01, respectively) and mass index (131 +/- 16 vs. 113 +/- 19 g/m2, p < 0.01), whereas hydralazine therapy showed no significant changes. Both regimens not only had a significant reduction in left ventricular mean wall stress but also had a mild increase in exercise duration. Only enalapril therapy achieved a significant inhibition of the renin-angiotensin system, in contrast to hydralazine therapy. Moreover, the multiple r2 value from the analysis for end-diastolic volume index using the two variables of age and treatment drugs was 72.1% (p < 0.01).

Conclusions: Both regimens decrease left ventricular mean wall stress. Enalapril therapy achieves significant left ventricular mass regression, left ventricular end-diastolic and end-systolic volume index reduction and renin-angiotensin system suppression. These findings suggest that early unloading enalapril therapy has the potential to favorably influence the natural history of chronic aortic regurgitation.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aortic Valve Insufficiency / diagnostic imaging
  • Aortic Valve Insufficiency / drug therapy*
  • Aortic Valve Insufficiency / physiopathology
  • Chronic Disease
  • Double-Blind Method
  • Echocardiography
  • Enalapril / therapeutic use*
  • Female
  • Follow-Up Studies
  • Hemodynamics / drug effects
  • Humans
  • Hydralazine / therapeutic use*
  • Male
  • Middle Aged
  • Renin-Angiotensin System / drug effects
  • Vasodilator Agents / therapeutic use*
  • Ventricular Function, Left / drug effects


  • Vasodilator Agents
  • Hydralazine
  • Enalapril