STS risk of operative mortality and long-term survival in isolated CABG patients

Objective: To assess the association between the Society of Thoracic Surgeons' (STS) risk of operative mortality and long-term survival among patients who undergo isolated CABG. Methods: The study cohort consisted of 4,931 consecutive patients who underwent isolated CABG at a academic medical center and two heart and vascular hospitals in Texas between 1/1/2004-10/31/2011 and were discharged alive. The patient cohort was limited to subjects without previous valve surgery, pre-operative endocarditis, or a ventricular assist device. Results: A survival model (Cox) considering the STS risk score as the only independent variable was fitted. Post-operative survival was assessed in all 4,931 patients using the Social Security Death Master File (SDM). Survival was measured in all patients as time (in days) from discharge to either death or last follow-up (November 1, 2011 – the last date SDM was publicly available to use for research). There were 583 (11.8%) deaths during follow-up (7 years and 10 months). Unadjusted survival was 77.6% at 7 years. The Cox model showed that the STS risk of operative mortality was significantly and highly associated with survival (p<0.0001, Figure 1). However, its impact was minimal –the variation explained by its effect in predicting survival was 9.6% (R2=0.096). ![Figure][1] Figure 1 Conclusion: Long-term mortality may be attributable to many causes, not necessarily related to patients' cardiovascular or general health at the time of operation. Thus, discussions with surgeons, and long-term shared decision-making with primary care physicians/cardiologists should not focus solely on patients' pre-operative risk profiles, but also emphasize the importance of preventing/controlling other diseases through a healthy lifestyle and compliance with disease management protocols. [1]: pending:yes