Background: Many high-risk patients with non-ST-elevation acute coronary syndromes within the SYNERGY trial required coronary artery bypass grafting (CABG) for optimal revascularization. We explored the clinical outcomes among high-risk patients undergoing CABG and the impact of modern pharmacology.
Methods: We evaluated 180-day rates of death and myocardial infarction (MI) and 30-day GUSTO severe bleeding among patients undergoing CABG, contrasting them with patients undergoing percutaneous coronary intervention (PCI) or medical management. The relationships between perioperative MI, bleeding events, and 6-month mortality were explored. The effect of random assignment to unfractionated heparin or enoxaparin and the relationships between use of clopidogrel and glycoprotein IIb/IIIa inhibitors and clinical outcomes were assessed.
Results: Death or MI at 6 months was more common among patients requiring CABG (CABG 31.2%, PCI 15.9%, medical 9.9%). Thirty-day GUSTO severe bleeding was also higher (CABG 6.4%, PCI 1.1%, medical 0.9%). Perioperative MI and GUSTO severe bleeding were associated with excess 6-month mortality (hazard ratio 2.1, 95% CI 1.27-3.53 and hazard ratio 7.6, CI 4.78-12.09, respectively). Randomization to enoxaparin was not associated with an increase in bleeding or a reduction in death or MI. No differences in ischemic outcomes were observed among patients given glycoprotein IIb/IIIa inhibition or clopidogrel.
Conclusions: High-risk patients still commonly require CABG with greater bleeding and ischemic event rates observed. Current definitions of perioperative MI and GUSTO severe bleeding portend an increased in 6-month mortality among CABG patients. Modern pharmacotherapies do not appear to impact these higher event rates.