EFFECT OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR THERAPY IN MITRAL REGURGITATION WITH NORMAL LEFT-VENTRICULAR FUNCTION

Mitral regurgitation (MR) is a common, frequently asymptomatic valvulo pathy that can ultimately lead to left ventricular failure. With the o bjective of forestalling MR progression, a prospective, placebo contro lled, double-blind study was conducted. It measured the effectiveness of lisinopril, an angiotensin converting enzyme inhibitor, in reducing the echocardiographic signs of MR severity over a one-year period. Se vere coronary disease was excluded by stress echocardiography. Treatme nt effectiveness was estimated to be proportional to the reduction in MR fraction and cardiac chamber dimensions, compared with baseline, ac cording to intention-to treat analysis. A final patient population of 23 asymptomatic adults aged 53.3+/-2.4 years (mean+/-SEM), with modera te, organic MR and normal left ventricular function was selected from the echocardiographic database. All baseline patient characteristics w ere comparable in the two treatment groups, including the MR fraction (55+/-3%). Twelve patients received lisinopril. (18+/-1 mg) and 11 rec eived placebo. After one year of treatment, a statistically significan t difference in the MR fraction was observed between the two groups. F or the lisinopril group the MR fraction dropped by 6.4+/-3.5% and for the placebo group it increased by 3.7+/-3.2% versus baseline (P<0.05). No differences in left atrial or Ventricular dimensions were observed . The study drug was stopped in four patients after one patient presen ted with rapid atrial fibrillation and angina while three patients wer e intolerant to lisinopril. Only one patient receiving placebo was tak en off therapy. In conclusion, treatment with lisinopril indicates som e reduction in the severity of chronic moderate MR in asymptomatic pat ients with normal left ventricular function. This approach appears to be safe, but side effects are not uncommon, warranting regular follow- up.