Calcification and degeneration following mitral valve reconstruction in patients requiring chronic dialysis

Background and aim of the study: Abnormal calcium homeostasis in patients w ith end-stage renal failure results in dystrophic calcification; this limit s the use of heterograft tissue valve prostheses in patients on chronic dia lysis. Mitral valve reconstruction offers advantages over mitral replacemen t in many patients without renal failure, and offers theoretical advantages in patients requiring dialysis. This study was performed to determine the outcome of mitral valve reconstruction in patients with renal failure requi ring chronic dialysis. Methods: Ten patients with end-stage renal failure and on chronic dialysis who underwent mitral valve repair were identified retrospectively and follo wed for clinical and echocardiographic outcome. All patients had good resul ts immediately following surgical valve mitral repair, with no more than mi ld mitral regurgitation and low transmitral gradients on intraoperative tra nsesophageal echocardiography. Results: Clinical and echocardiographic follow up was available for eight p atients at an average of 2.3 +/- 1.4 years after surgery. Despite there bei ng no significant valve calcification at the time of surgery, visible mitra l leaflet calcification was evident in seven of these patients, and the tra nsmitral gradient for the group was significantly increased (from 4.8 +/- 1 .7 mmHg to 8.3 +/- 3.9 mmHg, p = 0.04). Two patients required reoperation f or failed mitral repair; one at six months due to chordal rupture, and one at 15 months due to mitral calcification with stenosis. Conclusion: Despite good early surgical results, there was accelerated calc ification of the repaired mitral valve, a rapid increase in postoperative m itral gradients, and a high incidence of failure of the reconstruction. Add itional prospective studies are required to evaluate the optimal interventi on for patients with end-stage renal failure who require mitral valve surge ry.