THE MEDTRONIC-INTACT XENOGRAFT - AN ANALYSIS OF 342 PATIENTS OVER A 7-YEAR FOLLOW-UP PERIOD

Three hundred forty-two patients from December 1985 to January 1993 re ceived 352 Medtronic Intact porcine xenograft valves (zero-pressure gl utaraldehyde-fixed with toluidine blue anticalcification agent). The f ollow-up was 99.4% complete with a mean of 3.14 years (3 months to 7.9 years). The mean patient age was 64 years (range, 16 to 82 years) and the median age was 67 years. There were 14 aortic valve replacement p atients (11.9%) and 62 mitral valve replacement patients (29.2%) who p reoperatively were in New York Heart Association class IV to V. The ho spital mortality was 8.4% +/- 2.9% (aortic valve replacement, 5.9%; mi tral valve replacement, 9.4%; tricuspid valve replacement, 7.6%). Actu arial patient survival at 7 years was 65% +/- 5% (aortic valve replace ment, 77% +/- 5%; mitral valve replacement, 63% +/- 5%). At 7 years, t he freedom from thromboembolism was 74% +/- 4%, freedom from endocardi tis 93% +/- 2%, and freedom from reoperation 90% +/- 3%. Reoperation w as required for endocarditis (7 patients), periprosthetic leak (6), an d 2 of 3 cases of structural deterioration. The actuarial freedom from structural deterioration at 5 years was 97% +/- 3%. The combined inci dence of all important morbid valve-related events was analyzed with a n actuarial freedom at 7 years of 63% +/- 3%. The durability of the Me dtronic Intact is at least equal to that of other porcine bioprosthese s. The relevant important time-frame of 7 to 12 years of follow-up has just begun, and possibly the reoperation rate for intrinsic value fai lure and the low incidence of calcification in the elderly patient may be showing improved characteristics of this valve. No stronger infere nces are possible at this stage of the 7-year follow-up.