Table 1:

Best evidence papers discussing CABG timing for NSTEMI

Author (date), journal, country, Sutdy type, level of evidence	Patient group	Outcomes	Key results	Comments
Braxton et al. (1995) Circulation, USA [2] Retrospective study (level 3 evidence)	368 patients undergoing CABG with no MI (252 patients) and with previous Q and non-Q MI (116 patients). Patients were divided into <48 h, 3–5 days and 6–42 days from admission to CABG	Hospital mortality Requirement for vasopressors, IABP, hospital stay Perioperative MI	Non-Q wave MI patients showed similar overall mortality (3.4%) to non-MI patients (2.4%) No differences were found at any of the studied time points with regard to need of vasopressors, IABP or hospital stay Perioperative MI was higher in the <48 h group compared with non-MI patients	Non-Q wave MI patients may receive CABG surgery at any time with similar outcomes to non-MI patients. Nonetheless, there was no comparison regarding mortality between different time points in the non-Q wave MI patients
Deeik et al. (1998) Am J Surg, USA [3] Retrospective study (level 3 evidence)	214 patients undergoing CABG with no MI (155 patients, group I), non-transmural MI (39 patients, group II) and transmural MI (20 patients, group III)	Time from MI or admission to CABG Hospital mortality, length of stay	Group I were operated after a mean of 2.3 days, group II 4.2 days and group III 5.2 days No difference in hospital mortality nor length of stay	A waiting period of 3–5 days after non-transmural MI produces similar postoperative outcomes to those in non-MI CABG patients. There was no comparison between patients with non-transmural MI operated at different time points
Lee et al. (2001) Ann Thorac Surg, USA [4] Retrospective study (level 3 evidence)	21 382 patients with non-transmural acute MI received CABG at different time points after acute MI: <6 h, 6–23 h, 1–7 days, 8–14 days, ≥15 days	Hospital mortality Predictors of hospital mortality	Hospital mortality was higher when CABG was done <6 h from MI (11.5%) than 6–23 h (6.2%) or 1–7 days (3.5%) or 8–14 days (2.5%) or ≥15 days (2.5%) CABG <6 h from MI was an independent predictor of hospital mortality	Hospital mortality after CABG peaks in the first 6 h after MI, being stable thereafter
Parikh et al. (2010) JACC Cardiovasc Interv, USA [5] Retrospective study (level 3 evidence)	2647 NSTEMI patients who received early (<48 h; 825 patients) and late CABG (>48 h; 1822 patients)	Hospital mortality, MI, stroke, congestive heart failure Length of stay, transfusion	Hospital mortality, stroke, MI and congestive heart failure were similar in both groups Late CABG patients received more red blood cell transfusion and had longer in-hospital stay	Patients with late CABG were older, with more hypertension, diabetes, peripheral artery disease, prior MI, prior CABG, prior heart failure, prior stroke, higher creatinine value and lower haematocrit There was no difference in hospital mortality, MI and stroke between early and late CABG
Paparella et al. (2010) Ann Thorac Surg, Italy [6] Retrospective study (level 3 evidence)	184 patients with recent (onset <21 days) acute MI were divided into two groups based on cTnI values: 117 with <0.15 ng/ml and 67 with >0.15 ng/ml	Postoperative complications (ventilation time, IABP use, atrial fibrillation) 6 month survival	Patients with cTnI >0.15 ng/ml had longer ventilation time, more IABP use, higher incidence of atrial fibrillation The 6-month survival was worse in patients with cTnI >0.15 ng/ml	The 6-month mortality rate was lower in patients operated on during the second week after acute MI, but the difference was not statistically significant
Thielmann et al. (2006) Circulation, Germany [7] Retrospective study (level 3 evidence)	197 NSTEMI patients operated within 24 h of symptom onset. cTnI was measured before surgery	Hospital mortality and MACE	cTnI levels were independent predictors of hospital mortality and MACE. A cut-off value of 0.72 ng/ml was determined for cTnI and hospital mortality	Although the timing of CABG was considered, preoperative cTnI values were found to be stronger predictors of hospital mortality than EuroSCORE
Thielmann et al. (2005) Chest, Germany [8] Retrospective study (level 3 evidence)	NSTEMI patients were grouped as preoperative cTnI 0.1–1.5 ng/ml (265 patients) or cTnI >0.15 ng/ml (121 patients)	Perioperative MI, hospital mortality and MACE	Perioperative MI, hospital mortality and MACE were higher in patients with cTnI >0.15 ng/ml at the time of surgery	Preoperative cTnI was a strong predictor of hospital mortality in these patients

CABG: coronary artery bypass graft; cTnI: cardiac troponin I; EF: ejection fraction; IABP: Intra-aortic balloon pump; MACE: major adverse cardiovascular event; MI: myocardial infarction; NSTEMI: non-ST myocardial infarction.