Patient–prosthesis mismatch may be irrelevant after aortic valve replacement with the 19-mm Perimount pericardial bioprosthesis in patients aged 65 years or older

The prevalence of patient–prosthesis mismatch (PPM) and its influence on clinical midterm results were examined in elderly patients whose activity was supposed to be less than that of younger patients. We evaluated valve function and the effects of PPM on the midterm results of the 19-mm Carpentier–Edwards Perimount (CEP) pericardial aortic valve in patients aged 65 years or older. Between August 1996 and May 2005, 51 patients underwent aortic valve replacement with the 19-mm CEP valve. The mean follow-up was 2.4 ± 1.8 years, involving a total of 134.4 patient-years. The mean age and body surface area at operation were 74.0 ± 5.0 years and 1.41 ± 0.14 m². There were two (3.9%) operative deaths. Three patients (5.9%) underwent enlargement of their small aortic annuli. The actuarial survival rate at 8 years, including operative mortality, averaged 90.2% ± 4.7%. The freedom from thromboembolism, reoperation, and valve-related mortality averaged 75.0% ± 21.7%, 97.8% ± 2.2%, and 95.3% ± 3.2%, respectively, at 8 years. High preoperative peak and mean transvalvular pressure gradients were significantly improved after the operation (peak, 93 ± 35 versus 28 ± 12 mmHg; mean, 58 ± 19 versus 17 ± 7 mmHg, respectively; P < 0.01). The mean left ventricular mass index was reduced from 192 ± 44 to 142 ± 46 g/m² at late follow-up (P < 0.01). The prevalence of PPM was low (17.6%) when an indexed effective orifice area of less than 0.85 cm²/m² was taken as the definition of PPM. The clinical results, postoperative pressure gradients, and reduction in left ventricular mass index were not different between the PPM and no-PPM groups. The 19-mm CEP valve produced satisfactory midterm clinical outcomes in patients aged 65 years or older whose activity was supposed to be less than that of younger patients, regardless of the presence or absence of PPM. Moderate PPM was rare and it did not adversely impact on the midterm results. The application of annulus enlargement could be limited to the small number of patients for whom the 19-mm CEP valves are not able to be inserted.