Association between older age and outcome after cardiac surgery: a population-based cohort study

Objective: Octogenarians (aged >= 80 years) are increasingly being referred for cardiac surgery. We aimed to describe the morbidity, mortality, and health services utilization of octogenarians undergoing elective cardiac surgery. Methods: Retrospective population-based cohort study of adult patients receiving elective cardiac surgery between January 1 2004 and December 31 2009. Primary exposure was age >= 80 years. Outcomes were 30-day, 1-and 5-year mortality, post-operative complications, and ICU/ hospital lengths of stay. Multi-variable logistic and Cox regression analyses were used to explore the association between older age and outcome. Results: Of 6,843 patients receiving cardiac surgery, 544 (7.9%) were octogenarians. There was an increasing trend in the proportion of octogenarians undergoing surgery during the study period (0.3% per year, P = 0.073). Octogenarians were more likely to have combined procedures (valve plus coronary artery bypass or multiple valves) compared with younger strata (p < 0.001). Crude 30-day, 1-year and 5-year mortality for octogenarians were 3.7%, 10.8% and 29.0%, respectively. Compared to younger strata, octogenarians had higher adjusted 30-day (OR 4.83, 95% CI 1.30-17.92; P = 0.018) and 1-year mortality (OR 4.92; 95% CI, 2.32-10.46. P< 0.001). Post-operative complications were more likely among octogenarians. Octogenarians had longer post-operative stays in ICU and hospital, and higher rates of ICU readmission (P < 0.001 for all). After multi-variable adjustment, age >= 80 years was an independent predictor of death at 30-days and 1 year. Conclusions: Octogenarians are increasingly referred for elective cardiac surgery with more combined procedures. Compared to younger patients, octogenarians have a higher risk of post-operative complications, consume greater resources, and have worse but acceptable short and long-term survival.