Effect of losartan on exercise tolerance and echocardiographic parameters in patients with mitral regurgitation.

Objectives: The aim of this study was to assess the effects of losartan treatment on exercise tolerance and echocardiographic parameters in patients with mitral regurgitation (MR) secondary to mitral valve prolapse or rheumatic heart disease.

Methods: Twenty-seven patients (14 males, 13 females, mean age 51+/-11, range 21-76) with moderate MR due to mitral valve prolapse or rheumatic heart disease were examined by means of Doppler echocardiography. The subjects were submitted to treadmill exercise tests using the modified Bruce protocol at baseline, after six hours and after the six-week treatment period to be evaluated based on their exercise tolerance. Mitral Regurgitant Volume (MRV), effective regurgitant orifice diameter, left atrial volume, left ventricle (LV) end-diastolic volume index, LV end-systolic volume index, LV ejection fraction (LVEF), left ventricle mass index were calculated at baseline and after six weeks of treatment with single dose of losartan (50 mg/day).

Results: Total treadmill exercise time increased from 477.7+/-147.9 to 535.7+/-149.0 seconds after six hours (p<0.01) and to 559.6+/-142.8 seconds after six weeks of treatment. Also, metabolic equivalent values increased following six hours of first dose and six weeks of losartan treatment (from 10.9+/-2.9 to 11.8+/-3.1, p=0.006 and 12.4+/-3.1, p=0.002; respectively). However, peak exercise systolic blood pressure (BP) was reduced after six hours and six weeks of treatment, and resting diastolic BP did not change after six hours but reduced at the end of the treatment period. MR volume decreased significantly from 29.3+/-14.1 ml to 25.1+/-14.8 ml, (p=0.025) without significant change in regurgitant orifice diameter (0.72+/-0.37 cm vs. 0.66+/-0.37 cm, p=NS), left atrium diameter and area while LVEF increased from 51.70+/-13.37 to 54.11-11.75 (p=0.015) with losartan.

Conclusion: We conclude that the angiotensin II receptor antagonist losartan improves exercise tolerance and echocardiographic parameters in patients with moderate MR.