The Zero Pressure Fixed Medtronic Intact Porcine Valve: Clinical Results Over a 6-Year Period, Including Serial Echocardiographic Assessment

Abstract

Between 1983 and 1990, 219 patients had 224 Medtronic Intact porcine valves inserted. There were 94 aortic, 110 mitral, and 20 tricuspid valve replacements. The mean patient age was 52 years. Mean follow-up was 33.3 months and was 97.7% complete. There was only one example of structural valve degeneration occurring at 25 months, giving an actuarial freedom of 99% at 6 years. Reoperation was performed in seven patients. At 6 years, actuarial survival was 71%, freedom from infective endocarditis 96%, freedom from thromboembolism 91%, freedom from reoperation 93%, and freedom from valve-related complications 86%. Doppler echocardiography was performed in 48 of the 70 patients operated upon between August 1983 and October 1986 and who remained alive at the current review. Their follow-up averaged 4.7 (3-6.7) years. The results were compared to a similar examination performed in 1987 by the same operator. No patient had significant regurgitation. Valve gradients and areas remained the same in the two studies in the mitral position (3.8 +/- 1.33 mmHg) and the mean aortic gradient had reduced from 17 +/- 5.2 mmHg in 1987 to 13 +/- 2.8 mmHg in the current study (p = 0.02). These medium-term results are considered encouraging.