Mitral annulus calcification: determinants of repair feasibility, early and late surgical outcome

Abstract

The aim of this study was to determine the factors influencing the feasibility of valve repair and the surgical outcome in patients with mitral annulus calcification. In 124 patients with mitral annulus calcification undergoing surgery, two entities were distinguished: Barlow disease (myxomatous leaflets, n=60) and fibroelastic deficiency (FED) (normal leaflets, n=64). The calcification score was lower (1.9 vs 2.8); the annulus was more dilated (ring 35 vs 32 mm) and ruptured chordae were more frequent (77% vs 37%) in Barlow than in FED (p<0.001). The clinical profile was different: age (60+/-14 vs 73+/-8 years, p<0.001), systemic hypertension (22% vs 70%, p<0.001), chronic renal insufficiency (5% vs 22%, p<0.01), cancer (7% vs 25%, p<0.01). Multifocal atherosclerosis was less frequent in Barlow than in FED: carotid disease (17% vs 54%, p<0.001), aortic atheroma (21% vs 51%, p<0.001) and coronary disease (22% vs 56%, p<0.01). Echocardiography showed two different patterns in Barlow and FED: aortic valve stenosis (1.7% vs 31%), left atrial diameter (54 vs 49 mm), left ventricular end-diastolic diameter (62 vs 54 mm), interventricular septal thickness (11 vs 13 mm), and systolic pulmonary pressure (40 vs 56 mmHg), respectively (p<0.001). Bacterial endocarditis was observed in 24 cases (19%). The surgical technique was a valve repair in 68% and a replacement in 32%. The repair rate depended upon the extent of annulus calcifications (p<0.001) and the type of degenerative disease (95% vs 44% in Barlow and FED p<0.001). In-hospital mortality was 14% (Barlow: 5% vs FED: 23%, p<0.01). The mean follow-up was 50+/-41 months. Overall 5-year year survival was 76% (Barlow: 90% vs FED: 64%, p<0.001) and survival free from cardiac event was 69% at 5 years (Barlow: 87% vs FED: 52%, p<0.001). Five-year survival was higher following repair than replacement (84% vs 64% p<0.001). Chronic renal insufficiency and bacterial endocarditis were two predictors of early and late death (p<0.01). The aetiopathogeny of the degenerative mitral disease responsible for annulus calcifications corresponded to distinct anatomical, clinical and echographic patterns. It was a main determinant of repair feasibility, early and late surgical outcome.