Short- and long-term results after prosthetic mitral valve implantation in patients with severe mitral annulus calcification

OBJECTIVES: To investigate short- and long-term outcomes of a conservative decalcification approach in mitral valve replacement (MVR) surgery in the presence of mitral annulus calcification (MAC). METHODS: Of the 1038 patients who underwent MVR, 133 (13%) had significant MAC with at least 30% of the annular circumference heavily calcified. In most patients, the surgical approach to MAC included conservative decalcification, supra-annular prosthesis implantation and insertion of a pericardial patch between the MV annulus and the prosthesis. These patients were matched by a propensity score to a group of patients who underwent MVR without MAC (n = 118 in each group) and served as a control group. RESULTS: There were 6 early deaths in each group with an overall mortality of 5% (P = 0.90). Early complications included one major stroke in the non-MAC group and acute renal failure needing dialysis in 2 and 3 patients in the MAC and non-MAC groups, respectively. Mean follow-up was 55 +/- 37 months and 99.1% complete. There were 38 (33%) and 33 (29%) late deaths with an estimated survival of 61% and 69% at 6 years in the MAC and non-MAC groups, respectively (P = 0.55). At follow-up, functional class did not differ between groups (P = 0.096). Mean echo follow-up time was 40 +/- 35 months and was 83% complete. Freedom from moderate or severe mitral regurgitation was 95% and 98%, with an estimated freedom of 95% and 96% at 6 years (P = 0.20), and mean gradient was 4.9 +/- 2.3 mmHg and 5.2 +/- 2.0 mmHg for MAC and non-MAC groups, respectively (P = 0.58). CONCLUSIONS: A conservative approach for dealing with MAC is suitable for the majority of patients. Early and late clinical and echocardiographic outcomes did not differ between the MAC and non-MAC patients, including freedom from early and late occurrence of MV prosthesis paravalvular leak.