The Metformin in Coronary Artery Bypass Graft (CABG) (MetCAB) Trial
Status:
Completed
Trial end date:
2014-07-01
Target enrollment:
Participant gender:
Summary
Rationale:
In patients with a myocardial infarction, occlusion of a coronary artery induces myocardial
ischemia and cell death. If untreated, the area of myocardium exposed to this interruption in
blood supply, will largely become necrotic. The only way to limit final infarct size, is
timely reperfusion of the occluded artery. Paradoxically, however, reperfusion itself can
also damage myocardial tissue and contribute to the final infarct size ("reperfusion
injury"). Also during coronary artery bypass grafting (CABG), the myocardium is exposed to
ischemia and reperfusion, which will induce cell death. Indeed, postoperatively, the plasma
concentration of troponin I, a marker of cardiac necrosis, is increased, and associated with
adverse outcome. The anti-hyperglycaemic drug metformin has been shown in preclinical studies
to be able to reduce ischemia-reperfusion injury and to limit myocardial infarct size.
Moreover, metformin therapy improves cardiovascular prognosis in patients with diabetes
mellitus. Paradoxically, in patients with diabetes, current practice is to temporarily stop
metformin before major surgery for the presumed risk of lactic acidosis, which is a rare
complication of metformin. However, here is no evidence that this practice benefits the
patient. The investigators hypothesize that pretreatment with metformin can reduce myocardial
injury in patients undergoing elective CABG surgery