Predictors of Survival and Modes of Failure After Mitroflow Aortic Valve Replacement in 1,003 Adults

Midterm outcomes are unknown for patients undergoing aortic valve replacement (AVR) with a Mitroflow bovine pericardial prosthesis (Sorin Group, Inc) and without anticalcification treatment. Recent reports warn of early senescence in younger adults.

From January 2004 through December 2011, 1,003 adults underwent Mitroflow AVR. The mean follow-up time was 25.0 (standard deviation [20.6]) months (total, 2,060 patient-years; maximum, 9 years). The patients were stratified for analysis according to age at implantation: group A, <60 years (n = 63, 6.3%); group B, 60-69 years (n = 173, 17.2%); group C, 70-79 years (n = 432, 43.1%); and group D, 80 years or older (n = 335, 33.4%).

The mean age was 74.8 years (SD 9.8), and 609 patients (60.7%) were men. Aortic valve stenosis was present in 912 patients (90.9%), and 113 (11.3%) had severe aortic regurgitation. There were 27 (2.7%) early deaths, 15 of 431 (3.5%) underwent concomitant coronary artery bypass grafting while 12 of 572 (2.1%) did not (p = 0.18), and 151 patients (15.1%) died during follow-up. Nineteen AVRs (1.9%) required re-replacement through August 2013; 12 (63.2%) were associated with structural valve deterioration. The overall rates of freedom from valve-related reoperation at 3 and 5 years were 98.3% and 93.8%, respectively. Group A had the greatest number of reoperations (6/63; p < 0.001). The overall survival rates at 1 and 5 years were 91.2% and 67.3%, respectively. Independent predictors of mortality were poorer New York Heart Association functional class (hazard ratio [HR], 2.1; p < 0.001), atrial fibrillation (HR, 1.8; p = 0.002), and prior cardiac operation (HR, 1.8; p = 0.003).

Midterm follow-up shows acceptable hemodynamic performance of the Mitroflow biologic aortic valve prosthesis in selected patients 60 years old and older. Ongoing follow-up will be necessary to understand long-term performance and outcomes.