Objective: Perioperative graft failure following coronary artery bypass grafting (CABG) results in acute myocardial ischemia/infarction (PMI), which may necessitate an acute secondary revascularization procedure to salvage myocardium, in order to preserve ventricular function and improve patient outcome. Whether acute percutaneous coronary (re)intervention (PCI), emergency reoperation, or conservative intensive care treatment should be applied, is currently unknown.
Methods: In order to identify the source of PMI and to pursue the appropriate re-revascularization strategy, coronary repeat angiography was emergently performed in 118 among 5427 consecutive isolated CABG patients with evidence of PMI. As a result, patients immediately underwent acute PCI (group 1), emergency reoperation (group 2), or were treated conservatively (group 3). Primary study endpoint was postoperative myocardial infarct size, as measured by peak cardiac troponin I (cTnI) serum levels. Secondary endpoints were perioperative left ventricular ejection fraction (LVEF%), assessed by transesophageal echocardiography, major adverse cardiac events, and short- and midterm mortality.
Results: Repeat coronary angiography revealed early perioperative bypass graft failure in 67 among 118 patients and 84 among 214 bypass grafts after CABG. The number and type of failing bypass grafts were comparable between groups 1 and 2, but significantly different to that of group 3 (P<0.007). Acute PCI was applied in 25 patients, redo-CABG in 15 patients, and conservative treatment in 27 patients. Procedural peak cTnI serum levels were significantly different between groups 1 and 2 (81+/-18 ng/ml vs 178+/-62 ng/ml; P<0.001). Global LVEF was reduced during the acute ischemic event when compared with preoperative values (P<0.01). Thereafter, LVEF improved during follow-up within each group (P<0.001), but did not differ between the three groups. In-hospital and 1-year mortality were 12.0% and 20.0% in group 1, 20.0% and 27% in group 2, and 14.8% and 18.5% in group 3, respectively (P=NS).
Conclusions: Re-revascularization with emergency PCI may limit the extent of myocardial cellular damage compared with the surgical-based treatment strategy in patients with acute perioperative myocardial ischemia due to early graft failure following CABG.