Statins and long-term survival after isolated valve surgery: the importance of valve type, position and procedure

Objectives: To investigate whether valve position, type and procedure are important factors in determining the beneficial effects of statin therapy with regard to long-term survival in patients undergoing isolated single valve surgery.

Methods: A prospective single-institution cardiac surgery database was analysed. Univariate, multivariate stepwise linear, logistic and Cox regression analysis and propensity matching were performed to identify if statins were associated with increased survival post-valve surgery.

Results: Overall mortality was 3.4% (n = 172) for all cases, n = 5013. The median follow-up was 5.8 years. Kaplan-Meier survival analysis indicated that statin therapy was beneficial for all patients undergoing isolated valve surgery, n = 5013, P = 0.03 and isolated aortic valve surgery, n = 3220, P = 0.03, but not isolated mitral valve surgery n = 1793, P = 0.4. Cox regression analysis of the study cohort revealed that statin therapy was a significant factors determining long-term survival in the study cohort, postisolated aortic valve replacement and postisolated biological aortic valve replacement. Statins therapy was not associated with an increased long-term survival post-mitral valve replacement or repair. Propensity matching resulted in 1555 patients receiving statins being matched 1:1 with those not receiving statins. The results after propensity matching concurred with that of the Cox regression analyses, demonstrating that statin therapy was significantly associated with reduced in-hospital mortality, hospital length of stay and postoperative creatinine kinase, muscle-brain isoenzyme release.

Conclusions: Previous publications have not distinguished valve type, position and repair as possible factors influencing statin-therapy outcomes. Statin therapy is associated with increased long-term survival postaortic valve replacement with a biological valve only. Statin therapy had no survival benefit in patients undergoing mitral valve repair or a mechanical valve replacement. A randomized trial is necessary to confirm or refute our findings.