Optimal Timing of Surgical Revascularization for Myocardial Infarction and Left Ventricular Dysfunction

Background： The optimal timing of surgical revascularization for patients presenting with ST-segment elevation myocardial infarction （STEMI） and impaired left ventricular function is not well established. This study aimed to examine the timing of surgical revascularization after STEMI in patients with ischemic heart disease and left ventricular dysfunction （LVD） by comparing early and late results. Methods： From January 2003 to December 2013, there were 2276 patients undergoing isolated coronary artery bypass grafting （CABG） in our institution. Two hundred and sixty-four （223 male, 41 females） patients with a history of STEMI and LVD were divided into early revascularization （ER, 〈3 weeks）, mid-term revascularization （MR, 3 weeks to 3 months）, and late revascularization （LR, 〉3 months） groups according to the time interval from STEMI to CABG. Mortality and complication rates were compared among the groups by Fisher＇s exact test. Cox regression analyses were performed to examine the effect of the time interval of surgery on long-term survival. Results： No significant differences in 30-day mortality, long-term survival, freedom from all-cause death, and rehospitalization for heart failure existed among the groups （P 〉 0.05）. More patients in the ER group （12.90%） had low cardiac output syndrome than those in the MR （2.89%） and LR （3.05%） groups （P = 0.035）. The mean follow-up times were 46.72 ± 30.65, 48.70 ± 32.74, and 43.75 ± 32.43 months, respectively （P = 0.716）. Cox regression analyses showed a severe preoperative condition （odds ratio = 7.13, 95% confidence interval 2.05-24.74, P = 0.002） rather than the time interval of CABG （P 〉 0.05） after myocardial infarction was a risk factor of long-term survival. Conclusions： Surgical revascularization for patients with STEMI and LVD can be performed at different times after STEMI with comparable operative mortality and long-term survival. However, ER （〈3 weeks） has a higher incidence of postoperative low cardiac output syndrome. A severe preoperative condition rather than the time interval of CABG after STEMI is a risk factor of long-term survival.