Outcomes of Isolated Reoperative Coronary Artery Bypass Grafting in Elderly Patients

OBJECTIVE: Primary coronary artery bypass grafting (CABG) is performed routinely in elderly patients with good results. However, the risk profile and outcomes of reoperative CABG in elderly patients are not well defined. Our purpose was to study the risk profile and hospital outcomes of isolated reoperative CABG in elderly patients (75 years and older) compared to isolated primary CABG in the same age group. METHODS: Between January 1990 and December 2010, 3483 elderly patients (age ≥ 75 years) underwent isolated CABG at our institution. Of these, 129 (3.7%) underwent reoperative CABG. Data were prospectively collected in a computerized database. Independent predictors of hospital mortality were determined by multivariable logistic regression. RESULTS: Hospital mortality was 3.2% and 8.5% (p < 0.001) in elderly patients in the primary group and reoperative group, respectively. Perioperative myocardial infarction (MI) occurred in 2.9% and 8.5% (p < 0.001), and low cardiac output syndrome (LCOS) occurred in 6.2% and 20.9% (p < 0.001) of patients in the primary group and reoperative group, respectively. The prevalence of perioperative MI was threefold higher in elderly patients undergoing reoperative CABG with antegrade cardioplegia alone (11.5%) compared to combined antegrade/retrograde cardioplegia (3.9%). Additionally, mortality was higher in elderly patients undergoing reoperative surgery with use of antegrade cardioplegia alone (12.8% vs. 2%, p = 0.03). Combined use of antegrade and retrograde cardioplegia was independently protective from mortality in the reoperative group (OR = 0.10; p = 0.03). CONCLUSION: Elderly patients undergoing reoperative CABG have an approximately threefold increase in the risk of mortality compared to elderly patients undergoing primary CABG. The higher risk of mortality is primarily driven by a higher rate of perioperative MI and LCOS. Combined use of antegrade and retrograde cardioplegia was associated with lower perioperative MI and lower mortality.