In 1 analysis of 44 365 patients who underwent CABG after MI (22 984 with STEMI; 21 381 with NSTEMI), the inhospital mortality rate was similar in the 2 groups undergoing CABG 6 hours after diagnosis (12.5% and 11.5%, respectively), but it was higher in STEMI patients than in NSTEMI patients when CABG was performed 6 to 23 hours after diagnosis (13.6% versus 6.2%; P 0.006).262 The groups had similar in-hospital mortality rates when CABG was performed at all later time points (1 to 7 days, 8 to 14 days, and 15 days after the acute event).262 Similarly, in a study of 138 subjects with STEMI unresponsive to maximal nonsurgical therapy who underwent emergency CABG, the overall mortality rate was 8.7%, but it varied according to the time interval from symptom onset to time of operation. The mortality rate was 10.8% for patients undergoing CABG within 6 hours of the onset of symptoms, 23.8% in those Hillis et al 2011 ACCF/AHA CABG Guideline e665 undergoing CABG 7 to 24 hours after symptom onset, 6.7% in patients undergoing CABG from 1 to 3 days, 4.2% in those who underwent surgery from 4 to 7 days, and 2.4% after 8 days.266 In an analysis of data from 150 patients with STEMI who did not qualify for primary PCI and required CABG, the in-hospital mortality rate increased according to the time interval between symptom onset and surgery.239 The mortal- ity rate was 6.1% for subjects who underwent CABG within 6 hours of pain onset, 50% in those who underwent CABG 7 to 23 hours after pain onset, and 7.1% in those who underwent CABG after 15 days.239 Lastly, in another study, the time interval of 6 hours was also found to be important in STEMI patients requiring CABG. 