Sex differences in morphology and outcomes of mitral valve prolapse.

BACKGROUND: Mitral valve prolapse is more common in women than in men, but men more often have surgery for severe regurgitation.

OBJECTIVE: To compare morphology and outcomes of mitral valve prolapse in men and women.

DESIGN: Retrospective cohort study.

SETTING: The Mayo Clinic, Rochester, Minnesota.

PATIENTS: 4461 women and 3768 men who received a diagnosis of mitral valve prolapse by echocardiography from 1989 to 1998 (896 Olmsted County residents and 7333 referred patients).

MEASUREMENTS: Mitral prolapse characteristics (localization, leaflet thickening or flail, regurgitation), ventricular and atrial characteristics, cardiac surgery, and mortality.

RESULTS: Compared with men, women had less posterior prolapse (22% vs. 31%), less flail (2% vs. 8%), more leaflet thickening (32% vs. 28%), and less frequent severe regurgitation (10% vs. 23%) (P<0.001 for all comparisons). Regardless of the severity of regurgitation, left ventricular and atrial diameters were smaller in women than in men but were larger in women after normalization to body surface area. Among patients with severe regurgitation, women were less likely than men to undergo cardiac valve surgery (52% vs. 60%; adjusted risk ratio, 0.79 [95% CI, 0.74 to 0.84]). At 15 years, women with no or mild mitral regurgitation had better odds of survival than men (87% vs. 77%; adjusted risk ratio, 0.82 [CI, 0.76 to 0.89]), but those with severe regurgitation had worse survival than men (60% vs. 68%; adjusted risk ratio, 1.13 [CI, 1.01 to 1.26]). The survival rate 10 years after surgery was similar in women and men (77% vs. 79%; P=0.14). Observations in Olmsted County patients and referred patients were similar.

LIMITATION: Diagnoses were based on echocardiography, and clinical data at initial diagnosis, reason for index echocardiography, and cause of all deaths were lacking.

CONCLUSION: Morphology and severity of mitral valve prolapse differ according to sex. Among patients with severe regurgitation, women have higher mortality and lower surgery rates than men.