Effect of losartan on degree of mitral regurgitation quantified by echocardiography

The objective of this study was to determine the effect of oral losartan on the degree of mitral regurgitation (MR), The regurgitant volume and effect ive regurgitant orifice were quantified using 3 methods (flow convergence, quantitative Doppler, and quantitative 9-dimensional echocardiography) in 3 2 patients (26 men, mean age 67 +/-14 years) with MR, both at baseline and 4 hours after losartan (50 mg orally). Twenty-eight patients were also reev aluated after 1 month of continued treatment with losartan (50 mg/day). Wit h treatment, systolic blood pressure decreased from 143 +/- 16 to 130 +/- 1 8 mm Hg and left ventricular end-systolic wall stress from 173 +/- 46 to 15 6 +/- 44 g/cm(2) (both p <0.001). With treatment, regurgitant volume decrea sed (from 77 +/- 28 to 64 +/- 26 mi, -18 +/- 10%; p <0.001) in direct relat ion to the effective regurgitant orifice change (from 43 +/- 16 to 37 +/- 1 5 mm(2), -17 +/- 10%; p <0.001) but without significant change in regurgita nt gradient or duration. Wide individual variability in response was observ ed unrelated to the magnitude of blood pressure changes. Larger reduction i n regurgitant volume was observed in patients with a marked decrease in wal l stress (r = 0.47, p = 0.01) and higher baseline end-diastolic volume inde x (r = -0.38, p = 0.03) and regurgitant volume (r = -0.45, p = 0.01), Acute improvements were sustained and unchanged at 1 month (all p >0.15). Treatm ent of MR using the angiotensin receptor antagonist losartan produces a sig nificant and sustained decrease in the degree of MR, with decreases in regu rgitant volume and effective regurgitant orifice, However, the changes are of modest and variable magnitude, (C) 2001 by Excerpta Medica, Inc.