In autopsied patients dying <1 month post-CABG, operation-related focal subendocardial contraction band necrosis was present in 83% (48/58), suggesting reperfusion injury rather than graft occlusion.
Observational (n=58)
What is the character and pathogenesis of myocardial injury following coronary artery bypass graft (CABG) surgery?
Myocardial necrosis after CABG is predominantly contraction band necrosis associated with reperfusion through patent grafts rather than graft occlusion.
Myocardial infarction after coronary artery bypass graft (CABG) surgery has been described clinically in up to 30% of patients but there is little morphologic information about the character and pathogenesis of the myocardial injury. We studied myocardium in the distribution of bypassed and nonbypassed coronary arteries for the presence of contraction band necrosis as compared to coagulation necrosis, in 58 autopsied patients who died less than 1 month after surgery. Operation related necrosis consisting of focal subendocardial contraction band necrosis was present to some degree in 48 (83%) patients. Regional transmural necrosis was present in 22 (38%) patients and was of two types. Contraction band necrosis occurred in 18 patients and was in the distribution of a patent bypassed coronary artery in 15 of them. Coagulation necrosis was found in four patients, and in each was in the distribution of a new graft-releated coronary artery occlusion. The results suggest that coronary artery reflow through widely patent grafts following the period of operative nonperfusion, rather than graft or intrinsic coronary artery occlusion, accounts for the majority of operation-related myocardial "infarcts" associated with CABG surgery. Thus, prevention of intraoperative myocardial injury must also focus on characteristics of the phase of myocardial reperfusion.
Bulkely et al. (Thu,) conducted a observational in Myocardial infarction after CABG surgery (n=58). Coronary artery bypass graft (CABG) surgery was evaluated on Presence of contraction band necrosis as compared to coagulation necrosis. In autopsied patients dying <1 month post-CABG, operation-related focal subendocardial contraction band necrosis was present in 83% (48/58), suggesting reperfusion injury rather than graft occlusion.