October 4, 2005

By Sahar Bedrood B.S. and Asher Kimchi M.D.

Barcelona, Spain - Aortic regurgitation results in left ventricular overload and eventual worsening of function. Vasodilator’s, such as nifedipine or enalapril, reduce both the afterload and the volume that regurgitates into the left ventricular, thereby preserving left ventricular function. It has been suggested that such therapy may reduce the need for aortic-valve replacement. A study by Artur Evangelista, M.D. et al from the Hospital Universitai Vall d’Hebron in Barcelona, Spain identified possible beneficial effects of vasodilator therapy on left ventricular function and the need for aortic-valve replacement. Their study, published in the September 29, 2005 issue of The New England Journal of Medicine showed long-term vasodilator therapy did not reduce or delay the need for aortic-valve replacement in patients with severe aortic regurgitation.

The study randomly assigned 95 patients with asymptomatic severe aortic regurgitation and normal left ventricular function to receive nifedipine, enalapril or no treatment. The drugs were given in 20mg doses every 12 hours. In the study, 32 patients received nifedipine, 32 received enalapril and 31 received no treatment.

After seven years of follow-up, the rate of aortic-valve replacement was similar among the groups: 39 percent in the control group, 50 percent in the enalapril group and 41 percent in the nifedipine group (P = 0.62). There were no significant differences among the groups in aortic regurgitant volume, left ventricular size, left ventricular mass, mean wall stress, or ejection fraction.

Overall, this study indicates that vasodilator therapy with nifedipine or enalapril does not reduce or delay the need for aortic-valve replacement in patients with asymptomatic, chronic, severe aortic regurgitation and a normal left ventricular ejection fraction.

Co-authors: Artur Evangelista, M.D., Pilar Tornos, M.D., Antonia Sambola, M.D., Gaietà Permanyer-Miralda, M.D., and Jordi Soler-Soler, M.D.