Midterm evaluation of the Tissuemed (Aspire) porcine bioprosthesis: 493 patients, 506 bioprostheses

Background. Valve durability has been a major concern with bioprostheses, a nd the Tissuemed (Aspire) porcine bioprosthesis was designed to provide a s olution to structural valve failure. Because bioprostheses tend to fail by 8 years, the aim of our study was to determine its midterm durability and p erformance. Methods. We reviewed 506 prostheses that were implanted in 493 patients (28 7 men; mean age 73 +/- 6 years) between 1991 and 1999. Preoperatively 316 ( 68%) patients were in New York Heart Association class III or IV. There wer e 417 (85%) aortic, 61 (12%) mitral, 13 (2.6%) aortic and mitral, and two ( 0.4%) tricuspid procedures. Concomitant procedures were performed in 163 (3 3%) patients. Follow-up was complete in 488 (98.9%) patients with a total c umulative follow-up of 1,402 patient-years. Results. The 30-day mortality in this elderly population was 10% (95% confi dence interval, 8 to 13), with no early valve-related deaths. Patients' sur vival at 8 years was 46% +/- 7%. This was influenced by the following facto rs: (1) the patient's age, being worse for those 70 years or older (p = 0.0 05); (2) those in New York Heart Association functional class III and IV [p = 0.004); (3) those in atrial fibrillation before the operation (p = 0.006 ); (4) those with poor left ventricular function (p = 0.009); and (5) those who had a previous cardiac operation (P = 0.003). Valve-related complicati ons (expressed as percent per patient-year) were thromboembolism at 0.9%/pa tient-year; major hemorrhage at 1.4%/patient-year; bacterial endocarditis a t 0.4%/patient-year; nonstructural dysfunction at 0.20%/patient-year, and r eoperation at 0.2%/patient-year. At 8 years, freedom from thromboembolism w as 93% +/- 7%, major hemorrhage, 90% +/- 4%, nonstructural dysfunction, 99% +/- 1%, structural valve failure, 100%, and reoperation, 99% +/- 1%. At fo llow-up, 98% of survivors were in New York Heart Association class I or II. Conclusions. Our study suggests that at 8 years, the Tissuemed (Aspire) por cine bioprosthesis is durable and has satisfactory performance with low com plication rates. (Ann Thorac Surg 2001;71:1471-6) (C) 2001 by The Society o f Thoracic Surgeons.