Does Mitral Valve Calcium in Patients Undergoing Mitral Valve Replacement Portend Worse Survival?

BACKGROUND

Mitral annular calcification (MAC) is associated with worse outcomes after mitral valve replacement (MVR). With limited data available on long-term outcomes, we reviewed our experience of MVR in presence of MAC.

METHODS

A retrospective review of 1,710 consecutive patients who underwent MVR between January 2000 and December 2015 was performed. Patients with isolated primary MVR (n = 496) were included, whereas patients with concomitant cardiac surgery (n = 1,068), previous MVR (n = 110), and mitral valve (MV) endocarditis (n = 36) were excluded. MV calcification was classified as MAC present in anterior/posterior annulus and vertically at the level of leaflets/subvalvular apparatus. A conservative approach towards annular debridement was followed.

RESULTS

Our sample's mean age was 64.4 ± 14.1 years, and included 279 (56%) women. MV calcification was observed in 169 (34%) patients with MAC in 115 (23%). Older age, higher ejection fraction, peripheral vascular disease, diabetes, dialysis, and previous aortic valve surgery were associated with increased prevalence of MAC. Patients with MV calcification had higher stroke rate (p = 0.040), patients with anterior leaflet and commissural calcification had higher pacemaker implantation (p = 0.010, p = 0.001, respectively), and patients with circumferential MAC had higher postoperative dialysis (p = 0.006). Operative mortality was not significantly different (p = 0.466) between MAC (n = 1, 1%) and non-MAC (n = 9, 2%) patients. MAC was associated with late mortality (unadjusted hazard ratio, 1.62; 95% confidence interval, 1.20 to 2.18), though on multivariable analysis age, diabetes, dialysis, hypertension, previous aortic valve surgery, previous coronary artery bypass grafting, and MVR with a bioprosthetic valve were found to be independent risk factors for mortality whereas MAC was not.

CONCLUSIONS

A conservative approach to treat MAC achieves satisfactory results. Patients with MAC have significant comorbidities contributing to a worse survival, though MAC in itself is not a risk factor for mortality.