Predictors and Outcomes of Coronary Artery Bypass Grafting in ST Elevation Myocardial Infarction

Background Treatment of ST-elevation myocardial infarction has undergone great evolution since introduction of percutaneous coronary intervention (PCI). The purpose was therefore to assess the outcome of patients with ST-elevation myocardial infarction undergoing surgical revascularization with coronary artery bypass grafting (CABG). Methods A total of 138 consecutive patients with ST-elevation myocardial infarction underwent CABG therapy between January 2000 and January 2007 at our institution. Prospectively recorded preoperative, intraoperative, and postoperative data were retrospectively screened for in-hospital mortality and major adverse cardiac events (MACE). Results The delay between the onset of ST-elevation myocardial infarction symptoms and CABG procedures was within 6 hours in 37 patients, 7 to 24 hours in 21, 1 to 3 days in 15, 4 to 7 days in 24, and 8 to 14 days in 41 patients. Cardiogenic shock (Killip class ≥III) was present in 38 patients (28%), and 37 patients (27%) were referred for CABG after failed PCI. Overall in-hospital mortality was 8.7%, but mortality varied between 10.8% (≤6 hours), 23.8% (7 to 24 hours), 6.7% (1 to 3 days), 4.2% (4 to 7 days), and 2.4% (8 to 14 days), depending on time interval from symptom onset to operation. Overall, more nonsurvivors were women (58% versus 23%; p < 0.01), had higher preoperative cardiac troponin I levels (13.2 ± 9.8 versus 4.5 ± 4.2 ng/ml; p < 0.0001), and were more frequently in cardiogenic shock (83% versus 22%; p < 0.0001). Unadjusted univariable and risk-adjusted multivariable logistic regression analysis revealed age, female sex, preoperative cardiac troponin I levels, and cardiogenic shock to be the most potent predictors of in-hospital death and MACE. Conclusions CABG in ST-elevation myocardial infarction can be performed with acceptable risk by incorporating adequate management strategies. However, female sex, preoperative cardiac troponin I level, preoperative cardiogenic shock, and time to operation are major variables of mortality and morbidity results.