Early follow-up of patients with the Medtronic Intact porcine valve. A new cardiac bioprosthesis.

A new-generation porcine valve fixed in glutaraldehyde at zero pressure and mounted on an acetal copolymer flexible stent was inserted in 97 patients between August 1983 and October 1986. The mean age of the patients was 51 years (range 10 to 76) and eight were under the age of 20 years. There were 57 mitral, 33 aortic, and 10 tricuspid valve replacements. Concomitant coronary artery bypass grafting was performed in 9% of patients, 40% underwent multiple valve operations, and in 40% the procedure was a reoperation. Mean follow-up was 26 months (range 12 to 49) and was 99% complete. There were no examples of primary tissue failure, and only to reoperations have been undertaken for infective endocarditis alone. The early mortality rate was 8.2% and the late mortality rate, 12.1%. Four late deaths were valve related (two caused by infective endocarditis and two by embolism). The actuarial 3-year survival rate was 70%, freedom from infective endocarditis 879%, freedom from embolism 87%, freedom from reoperation 90%, and freedom from valve-related complications 77%. All but three surviving patients were in New York Heart Association class I or II. Doppler echocardiography, performed in 62 of 76 survivors, showed thin and mobile leaflets in all patients and trivial or mild regurgitation in four (6%). The mean gradient across the Medtronic Intact valves (Medtronic Blood Systems Inc., Minneapolis, Minn.) in the aortic position was 17 +/- 5.2 mm Hg, in the mitral position 3.8 +/- 1.33 mm Hg, and in the tricuspid position 4.1 +/- 1.14 mm Hg. We conclude that early results with the Intact valve are encouraging.