Improving results for coronary artery bypass graft surgery in the elderly

The proportion of elderly patients undergoing isolated coronary artery bypass grafting (CABG) surgery has steadily increased. We have evaluated temporal trends in hospital outcomes of patients who were 75 years and older undergoing CABG (1990-2010) at our institution.

Data were collected prospectively for 3483 consecutive patients who were 75 years and older (median 78 years; range 75-94) undergoing isolated CABG at our institution over three time cohorts: 1990-96 (n = 817), 1997-2003 (n = 1534) and 2004-10 (n = 1132).

Overall mortality declined from 6.0% (49/817) in the earliest era (1990-96) to 1.9% (22/1132) in the most recent era (2003-10; P < 0.001). Mortality in low-risk patients (elective, primary surgery with the ejection fraction >40%) was 5.9% (13/220), 0.8% (4/514) and 0% (0/411) in the first, second and third eras, respectively (P < 0.001). Despite the overall increase in comorbidities in our elderly patients, the prevalences of certain risk factors such as poor LV function, urgency of surgery and reoperation have all declined with time. The independent risk factors for mortality in our population were congestive heart failure, left main disease, earlier year of operation, reoperation, preoperative myocardial infarction, cardiopulmonary bypass time, emergent/urgent surgery and peripheral vascular disease. Of these, earlier year of operation (OR: 3.0; 95% CI: 1.8-5.2) was the most significant predictor. Also, age >80 did not predict mortality.

The principle finding from this analysis is a contemporary low operative mortality for CABG in an elderly patient cohort. Risk of death is particularly low in a low-risk subset of elderly patients with reasonable LV function undergoing elective, primary CABG.