Vasodilators including angiotensin converting enzyme inhibitor(ACEI) have been suggested to reduce left ventricular volume and to improve left ventricular performance in patients with moderate to severe regurgitant valvular heart diseases. However, long-term effects of angiotensin converting enzyme inhibitor upon left ventricular size and function in asymptomatic or minimally symptomatic patients with chronic mitral regurgitation remain to be elucidated.

Forty five patients with moderate to severe chromic mitral regurgitation on echocardiography and mild or no symptoms were studied. Serial changes of left ventricular dimension and ejection fraction were analyzed retrospectively using M-mode echocardiography in patients treated with ACEI(ACEI group, n=21) and in patients treated with other medications except ACEI or with no medication(non-ACEI group, n=24).

The mean duration of follow-up was 30±15 months. ACEI group showed trends of decreasing left ventricular end-systolic dimension(LVESD) and left ventricular end-diastolic dimension(LVEDD) and a trend of increasing ejection fraction(EF), though statistically insignificant when compared to those of before-treatment or non-ACEI group. In patients with larger initial LVESD(>35mm), LVEDD was reduced(the percent changes of LVEDD 2 and 3 years after ACEI treatment were -4.2# and -4.4%) that was significantly different from those of non-ACEI group(+3.4% and +3.4% each)(p<0.05). In patients with larger initial LVEDD(>60mm), the percent changes of LVEDD 2 and 3 years after ACEI treatment were -4.9% and -5.8%, and in patients with initial EF less than 60%, the percent change of LVEDD 2 years after ACEI treatment was -0.57%. Those changes were also statistically significant compared to those of non-ACEI group(p<0.05 each).

In mildly symptomatic chronic mitral regurgitation patients, especially whose left ventricular dimension is increase, long-term ACEI therapy seems to be effective in preventing left ventricular dilatation or in reducing left ventricular volume and such therapy may have a beneficial effect on the natural history of such patients.