Prophylactic warfarin post anterior ST-elevation myocardial infarction: A systematic review and meta-analysis

To determine the role of warfarin (WF) prophylaxis in the prevention of left ventricular thrombus (LVT) formation and subsequent embolic complications following an anterior ST elevation myocardial infarction (STEMI) complicated by reduced left ventricular ejection fraction (LVEF) and wall motion abnormalities.

The role of oral anticoagulation prophylaxis, in addition to dual antiplatelet therapy (DAPT), in the current era of percutaneous coronary intervention has not been well studied, despite being a class IIb recommendation in the AHA/ACC STEMI guidelines.

The Cochrane search strategy was used to search PubMed, Embase and the Cochrane library for relevant results. Four studies, two retrospective, one prospective registry, and a randomized feasibility control trial met criteria for inclusion. Data was pooled using a random effects model and reported as odds ratios (OR) with their 95% confidence intervals (CI). Primary outcomes of interest were rate of stroke, major bleeding and mortality.

Pooled analysis included 526 patients in the No WF group and 347 patients in the WF group. No statistical difference in rate of stroke (OR: 2.72 [95% CI: 0.47-15.88; p=0.21]) or mortality (OR: 1.50 [95% CI 0.29-7.71; p=0.63]) was observed. Major bleeding was significantly higher in the WF group (OR: 2.56 [95% CI: 1.34-4.89; p=0.004]).

The routine use of DAPT and WF for prophylaxis against LVT formation following an anterior STEMI with associated decrease in LVEF and wall motion abnormalities, appears to result in no mortality benefit or reduction in stroke rates, but may increase the frequency of major bleeding.