Outcomes and Prognostic Impact of Prophylactic Oral Anticoagulation in Anterior ST‐Segment Elevation Myocardial Infarction Patients With Left Ventricular Dysfunction

Abstract

BackgroundThe contemporary role of prophylactic anticoagulation following extensive anterior wall ST‐segment myocardial infarction (STEMI) is unclear.Methods and ResultsWe evaluated anterior STEMI patients with left ventricle dysfunction (left ventricular ejection fraction ≤40%) (“high risk”), categorized by prophylactic warfarin use, within a regional STEMI. Patients with pre‐existing atrial fibrillation were excluded. The primary outcome was an adjusted (for Global Registry of Acute Coronary Events risk score) 1‐year composite of recurrent ischemia, stroke/transient ischemic attack/systemic embolism, or all‐cause death. Of the 2032 STEMI admissions, 436 (21.5%) were high risk. After excluding 19 (4.4%) patients with definite left ventricle thrombus and 21 (4.8%) in‐hospital deaths (2 had left ventricle thrombus), prophylactic warfarin was utilized in 236/398 (59.3%) high‐risk survivors. Prescriptions were comparable across sex, but recipients were on average younger (58.5 years versus 64.0 years, P<0.001) and lower risk (Global Registry of Acute Coronary Events risk: 163 versus 181, P<0.001). No association on the adjusted ischemic composite (23.3% versus 25.3%, odds ratio 0.96, 95% CI 0.60–1.55) or thromboembolic events (2.1% versus 1.2%, odds ratio 1.99, 95% CI 0.38–10.51) was observed, but reduced 1‐year all‐cause mortality was noted (2.5% versus 8.6%, odds ratio 0.30, 95% CI 0.11–0.81); numerically higher major bleeding was observed at 1 year (2.5% versus 1.2%, odds ratio 2.17, 95% CI 0.43–10.96).ConclusionsA high utilization of prophylactic warfarin occurs in anterior STEMI patients with left ventricle dysfunction, yet appears to provide no additional benefit on the ischemic composite. The association with lower all‐cause mortality, but higher bleeding, calls for an improved understanding of its role in high‐risk STEMI.

2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Focused Update of the Guidelines for the Use of Antiplatelet Therapy

“…Shavadia et al recently reported similar results with no benefit for triple therapy in a series of consecutive STEMI patients with anterior LV dysfunction. 130 In patients with established LVT who undergo PCI for an ACS or non-ACS indication we make the following recommendation.…”

Left ventricular thrombosis in acute anterior myocardial infarction: Evaluation of hospital mortality, thromboembolism, and bleeding

“…Both guidelines suggest reevaluation of LV thrombus with routine imaging and considering stopping anticoagulation with continuation of antiplatelet therapy. Prophylactic warfarin without LVT on echocardiography has been studied in high‐risk STEMI patients (anterior wall infarct and LVEF ≤ 40%) . It was not associated with reduced thromboembolic events but was associated with increased risk of bleeding.…”

Anticoagulation in the cardiac patient: A concise review

“…86 While some data suggest a benefit in preventing recurrent cardiovascular events, recent data have failed to find a decrease in the incidence of cardiovascular events, but did show a numerically increased rate of major bleeding. 87 Atrial thrombi most commonly involve the left atrial appendage and are most often associated with atrial arrhythmia. Treatment generally involves indefinite anticoagulation as is recommended for atrial fibrillation.…”

“…The role of prophylactic anticoagulation following anterior myocardial infarction is unclear . While some data suggest a benefit in preventing recurrent cardiovascular events, recent data have failed to find a decrease in the incidence of cardiovascular events, but did show a numerically increased rate of major bleeding …”