Optimal timing of revascularization: Transmural versus nontransmural acutemyocardial infarction

Background. Higher mortality for emergency coronary artery bypass grafting (CABG) after an acute myocardial infarction (AMI) is well established. Whet her it applies to both transmural and nontransmural AMI is unclear. This in formation may have different therapeutic implications for each cohort of pa tients. Methods. A retrospective multicenter analysis of 44,365 patients who underw ent CABG after myocardial infarction between 1993 and 1996 by 179 surgeons at 32 hospitals in New York State was performed. Results. Overall hospital mortality for all patients with or without AMI wa s 2.5% versus 3.1% for patients who underwent CABG with history of myocardi al infarction. Hospital mortality decreased with increasing time interval b etween CABG and AMI; 11.8%, 9.5%, and 2.8% (p < 0.001 for all values) for l ess than 6 hours, 6 hours to 1 day, and greater than 1 day, respectively. P atients with transmural and nontransmural AMI had identical mortality of 3. 1%. However, different patterns emerged when comparing these two groups of patients with respect to time of operation. Mortality was higher in the tra nsmural group if CABG was performed within 7 days after AMI. Multivariate a nalysis confirmed that CABG within 1 day and 6 hours of AMI are independent risk factors for mortality in the transmural and nontransmural groups, res pectively. Conclusions. Early operation after transmural AMI has a significantly highe r risk, and surgeons should be prepared to provide aggressive cardiac suppo rt including left ventricular assist devices in this ailing population. Wai ting in some may be warranted. (C) 2001 by The Society of Thoracic Surgeons .