Risk factors for atherosclerosis and the degeneration of pericardial valves after aortic valve replacement

BACKGROUND: Recent studies have demonstrated the influence of atherosclerotic risk factors on the progression of aortic stenosis. We hypothesized that risk factors for atherosclerosis might also be involved in the degeneration of pericardial heart valves and might lead to reoperation as a result of structural valve failure, especially in younger patients with high degeneration rates. METHODS: In 1984 and 1985, 161 patients (74% male; mean age, 54.4 +/- 1.0 years; age range, 17-76 years; median age, 56.5 years) survived isolated aortic (n = 137) or combined aortic and mitral (n = 25) valve replacement with a Hancock extracorporeal pericardial valve. Of these patients, 90 (56%) had reoperations as a result of tissue failure of the aortic valve 5.6 +/- 0.25 years postoperatively. RESULTS: The patient group was split in half at the median age. In patients aged 57 years or younger, diabetes mellitus, female sex, cigarette smoking, and high cholesterol and triglyceride levels were associated with accelerated valve failure. In a multivariate model sex (female, P =.001), smoking (P =.001), diabetes mellitus (P =.020), and cholesterol levels (P =.011) are risk factors for reoperation. Patients without risk factors had reoperation after a mean of 9.25 +/- 0.88 years compared with 4.05 +/- 0.43 years (P =.0002) in patients with 2 or 3 risk factors. CONCLUSIONS: Risk factors of atherosclerosis might play a substantial role in the degeneration of aortic bioprosthetic valves. Lowering of serum lipid levels, smoking cessation, therapy for diabetes, and careful patient selection could be new strategies to postpone degeneration. Younger patients could then possibly benefit from the advantages of bioprostheses.