Progression of mitral regurgitation - A prospective Doppler echocardiographic study

OBJECTIVES This study was performed to define the rates and determinants of progression of organic mitral regurgitation (MR). BACKGROUND Severe MR has major clinical consequences, but the rates and det erminants of progression of the degree of regurgitation are unknown. Quanti tative Doppler echocardiographic methods allow the quantitation of regurgit ant volume (RVol), regurgitant fraction (RF) and effective regurgitant orif ice (ERO) to define progression of MR. METHODS In a prospective study of. MR progression, 74 patients had two quan titative Doppler echocardiographic examinations of MR (with at least two me thods) 561 +/- 423 days apart without an intervening event. RESULTS Progression of MR was observed, with increase in RVol (77 +/- 46 ml vs. 65 +/- 40 ml, p < 0.0001), RF (47 +/- 16% vs. 43% +/- 15%, p < 0.0001) , and ERO (50 +/- 35 mm(2) vs. 41 +/- 28 mm(2), p < 0.0001). Annual rates ( 95% confidence interval) were, respectively, 7.4 ml/year (5.1, 9.7), 2.9%/y ear (1.9, 3.9) and 5.9 mm(2)/year (3.9, 7.8). However, wide individual vari ation was observed, and regression and progression of RVol >8 ml was found in 11% and 51%, respectively. In multivariate analysis, independent predict ors of progression of RVol were progression of the lesions, particularly a new flail leaflet (p = 0.0003), and progression of mitral annulus diameter (p = 0.0001). Regression of MR was associated with marked changes in afterl oad, particularly decreased blood pressure (p = 0.008). No significant effe ct of treatment was detected. CONCLUSIONS Organic MR tends to progress over time with increase in volume overload (RVol) due to increase in ERO. Progression of MR is variable and d etermined by progression of lesions or mitral annulus size. These data shou ld help plan follow up of patients with organic MR and future intervention trials. (J Am Coll Cardiol 1999;34:1137-44) (C) 1999 by the American Colleg e of Cardiology.