Predicting 1-year Mortality After Off-pump Coronary Artery Bypass Grafting in Elderly Patients: Role of Pre-operative Myocardial Infarction and Post-operative Intra-aortic Balloon Pump Use

Objectives: Coronary artery disease (CAD) remains one of the leading causes of morbidity and mortality in the elderly, with patients over 70 years of age representing a rapidly growing cohort in need of revascularization. Although off-pump coronary artery bypass grafting (OPCAB) has been advocated in this population to reduce the complications associated with cardiopulmonary bypass, several studies have shown that the elderly still experience high rates of 1-year mortality despite the theoretical benefits of the off-pump technique. The current study aimed to determine the outcome of patients more than 70 years of age who underwent elective OPCAB for CAD. The primary objective was to determine the 30-day post-surgery survival. The secondary objectives were to assess the incidence of immediate post-operative complications, intensive care unit (ICU) and hospital stay lengths, and 1-year survival after surgery. Material and Methods: This was a single-center, retrospective observational study. Medical records of all patients aged >70 who underwent off-pump coronary artery bypass graft from April 2021 to April 2023 by a single cardiac surgeon at our center were accessed. The following data were collected – baseline demographic data, diagnosis, surgery performed, post-operative bleeding, surgery for mediastinal exploration, inotropic support, blood transfusion, duration of mechanical ventilation, length of ICU and hospital stay, need for intra-aortic balloon pump (IABP), tracheostomy, acute kidney injury (AKI), new-onset arrhythmias, pneumonia, ventilator-associated pneumonia (VAP), sepsis, 30-day, and 1-year mortality. Results: Twenty-four patients over 70 years of age underwent OPCAB during the study period. The 30-day survival was 91.6% (22/24), and the 1-year survival was 81.8% (18/22) in patients discharged from the hospital. There were three females and 21 males. There was no statistically significant difference between survivors and non-survivors in terms of age, height, weight, body surface area, duration of mechanical ventilation, drain output, inotropic score, ICU stay, and hospital stay. There was also no significant difference regarding sex, re-exploration, VAP, AKI, need for tracheostomy, and 30-day mortality. Pre-operative myocardial infarction (MI) and the use of IABP in the post-operative period were significantly associated with 1-year mortality after OPCAB. Conclusion: Pre-operative MI and post-operative IABP use were both independently associated with increased 1-year mortality in patients more than 70 years of age undergoing OPCAB.