Dual antiplatelet therapy for perioperative myocardial infarction following CABG surgery

Perioperative myocardial infarction (MI) after coronary artery bypass graft surgery (CABG) has been associated with adverse outcome. Whether perioperative MI should be treated with dual antiplatelet therapy (DAPT) is unknown. We compared the effect of DAPT versus aspirin alone on short-term outcomes among patients with perioperative MI following CABG.

We used data from 3 clinical trials that enrolled patients undergoing isolated CABG: PREVENT IV (2002-2003), MEND-CABG II (2004-2005), and RED-CABG (2009-2010) (n = 9117). Perioperative MI was defined as CK-MB >5 times the upper limit of normal within 24 h of surgery (n = 2052). DAPT was defined as DAPT given after surgery and prior to discharge. A Cox regression model was used to assess the association between DAPT and 30-day nonfatal MI, stroke, or mortality after adjustment for baseline covariates.

DAPT (n = 527) and aspirin alone (n = 1525) cohorts were similar in baseline comorbidities. Off pump bypass was used in 5.2% (n = 106) of patients. There was no difference in the 30-day composite of death, MI or stroke between patients receiving DAPT versus aspirin alone, nor in any of the individual components. There were fewer all-cause re-hospitalizations at 30 days following surgery among patients in the DAPT group (adjusted HR 0.71, CI 0.52-0.97, P = .033).

One-quarter of CABG patients who had perioperative MI were treated with DAPT. DAPT was not associated with a difference in MI, stroke, or mortality at 30 days, but was associated with fewer re-hospitalizations. Further studies are needed to determine the optimal antiplatelet regimen following perioperative MI. What is already known about this subject? Perioperative myocardial infarction portends poor outcome but optimal management is currently unclear. While dual antiplatelet therapy is standard of care for acute coronary syndrome, its role in perioperative myocardial infarction is unknown. What does this study add? Dual antiplatelet therapy use during perioperative myocardial infarction was not associated with a difference in myocardial infarction, stroke or mortality at 30 days. It was, however, associated with fewer re-hospitalizations at 30 days. How might this impact on clinical practice? Dual antiplatelet therapy may be a potential treatment option for perioperative myocardial infarction after CABG surgery. Further studies are needed to better understand treatment for this disease process.