Risk factors for in-hospital mortality after coronary artery bypass grafting in patients 80 years old or older: a retrospective case-series study

BACKGROUND: Age remains a significant and unmodifiable risk factor for cardiovascular diseases, and an increasing number of patients older than 80 years of age undergo Coronary Artery Bypass Grafting (CABG). Old age is also an independent risk factor for postoperative complications. The aim of this study is to describe the population of patients 80 years of age or older who underwent CABG procedure and to assess the mortality rate and risk factors for in-hospital mortality. METHODS: A retrospective case-series study analyzing 388 consecutive patients aged 80 years of age or older who underwent isolated CABG procedure between 2010 and 2014 in the Department of Cardiovascular Surgery and Transplantology, John Paul II Hospital, Krakow. RESULTS: In-hospital mortality stood at 7%, compared to 3.4% for all isolated CABG procedures at our Institution. In an univariate logistic regression analysis, risk factors for in-hospital mortality were as follows: NYHA class (p = 0.005, OR 1.95, 95% CI [1.23–3.1]), prolonged mechanical ventilation (p < 0.001, OR 7.08, 95% CI [2.47–20.3]), rethoracotomy (p = 0.04, OR 3.31, 95% CI [1.04–10.6]), duration of the procedure and ECC (for every 10 min p = 0.01, OR 1.01, 95% CI [1.0–1.01]; p = 0.03, OR 1.01, 95% CI [1.0–1.02], respectively), PRBC, FFP, and PLT transfusion (for every unit transfused p = 0.004, OR 1.42, 95% CI [1.12–1.8]; p = 0.002, OR 1.55, 95% CI [1.18–2.04]; p = 0.009, OR 1.93, 95% CI [1.18–3.14], respectively). Higher LVEF (p = 0.02, OR 0.97, 95% CI [0.94–0.99]) and LIMA graft implantation (p = 0.04, OR 0.36, 95% CI [0.13–0.98) decreased the in-hospital mortality. Death before discharge was more often observed in patients with multiple risk factors for cardiovascular diseases (0–2 –5.7%; 3–7.4%, 4–26.6%; p = 0.03). CONCLUSIONS: Older age is associated with higher in-hospital mortality after isolated CABG at our Institution. Risk stratification scores and individualized risk evaluation, centered on comorbidities, NYHA class and left ventricular function, should be assessed in all cases. Whenever suitable, LIMA grafts should be used. Prolonged procedure and ECC time worsen the short-term outcome. Elderly individuals should be closely monitored postoperatively and the care should be focused on excessive blood loss and respiratory failure.