The Influence of Choice of Surgical Procedure on Long-Term Survival After Cardiac Surgery

Background: There is some interest in long-term survival after various cardiac surgical strategies, including off-pump versus on-pump coronary artery surgery (CAG), mitral valve (MV) repair versus replacement, and aortic valve (AV) bioprosthetic versus mechanical replacement. Methods: We studied patients older than 49 years of age, recording risk factors and surgical details at the time of surgery. We classified procedures as: MV surgery with or without concurrent grafts or valves; AV surgery with or without concurrent CAG; or isolated CAG. Follow-up was through the state death register and state-wide hospital attendance records. Risk-adjusted survival was estimated using Cox proportional hazards. Observed survival was compared to the expected age- and sex- matched population survival. Results: During a median follow-up of 14.8 years 5,807 of 11,718 patients died. The difference between observed and expected survival varied between 3.4 years for AV surgery and 9.6 years for females undergoing MV surgery. The risk-adjusted mortality hazard rate after off-pump CAG was 0.93 (95% CI 0.8–1.0, p=0.84), MV repair 0.67 (95% CI 0.6–0.8, p<0.0001), MV bioprosthesis 0.82 (95% CI 0.81 (0.6–1.0, p=0.11) and bioprosthetic AV replacement 1.02 (95% CI 0.9–1.2, p=0.82). Conclusions: Compared to the general population, cardiac surgical patients have a shorter than expected life expectancy. We observed a survival benefit of mitral valve repair over replacement. We did not observe significant survival differences between off-pump and on-pump CAG, nor between bioprosthetic and mechanical replacement.