Cardiovascular risk factors as predictors of early and late survival after bioprosthetic valve replacement for aortic stenosis.

BACKGROUND AND AIM OF THE STUDY

Cardiovascular risk factors have been associated with aortic valve stenosis, which is considered as an atherosclerosis-like process. The study aim was to assess the effect of cardiovascular risk factors on early and late outcome after valve replacement with a bioprosthesis for aortic stenosis (AS), and the impact of these factors on the outcome of the bioprosthesis.

METHODS

Preoperative clinical, biological and echocardiographic data were recorded in 222 patients (110 males, 112 females; mean age 73 +/- 8 years) who underwent surgery for severe AS between 1989 and 1993. The mean follow up was 7.3 +/- 4.7 years; total follow up was 1,621 patient-years (pt-yr).

RESULTS

Overall 12-year actuarial survival rate was 36.1%. Independent predictors of mortality were age (hazards ratio (HR) 1.11; 95% CI: 1.08-1.14, p < 0.0001), diabetes mellitus (DM) (HR 2.53; 95% CI: 1.65-3.88, p < 0.0001), male gender (HR 2.17; 95% CI: 1.53-3.12, p < 0.0001), and NYHA class (HR 1.66; 95% CI: 1.17-2.34, p = 0.004). Other cardiovascular risk factors had no significant effect on survival. DM and NYHA class were also independent predictive factors for valve-related death and overall valve-related complications. The 12-year actuarial survival was 13% in DM patients compared to 38% in non-diabetic patients (p = 0.003), with a significant increase in cardiovascular death (p = 0.0028), and a non-significant increase in thromboembolic events (p = 0.08) in DM patients. The only independent predictive risk factor of structural valve failure in multivariate analysis was renal failure (HR 1.1, 95% CI: 1.03-1.16, p = 0.047). Cardiovascular risk factors such as hypercholesterolemia, DM, hypertension, tobacco smoking and obesity had no effect on the outcome of the bioprosthesis.

CONCLUSION

Age, male gender, DM and NYHA class were the main predictors for long-term mortality after bioprosthesis implantation for AS. DM significantly impaired survival, with an excess of cardiovascular deaths and thromboembolic events. Other cardiovascular risk factors had no significant effect on either survival or bioprosthesis durability.