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

J Am Heart Assoc. 2017 Jul 3;6(7):e006054. doi: 10.1161/JAHA.117.006054.

Abstract

Background: The contemporary role of prophylactic anticoagulation following extensive anterior wall ST-segment myocardial infarction (STEMI) is unclear.

Methods and results: We 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).

Conclusions: A 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.

Keywords: anticoagulant; stroke prevention; systolic dysfunction.

MeSH terms

  • Administration, Oral
  • Aged
  • Alberta
  • Anterior Wall Myocardial Infarction / diagnosis
  • Anterior Wall Myocardial Infarction / drug therapy*
  • Anterior Wall Myocardial Infarction / mortality
  • Anterior Wall Myocardial Infarction / physiopathology
  • Anticoagulants / administration & dosage*
  • Anticoagulants / adverse effects
  • Chi-Square Distribution
  • Female
  • Hemorrhage / chemically induced
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Odds Ratio
  • Propensity Score
  • Registries
  • Risk Factors
  • ST Elevation Myocardial Infarction / diagnosis
  • ST Elevation Myocardial Infarction / drug therapy*
  • ST Elevation Myocardial Infarction / mortality
  • ST Elevation Myocardial Infarction / physiopathology
  • Stroke / diagnosis
  • Stroke / mortality
  • Stroke / prevention & control*
  • Stroke Volume
  • Thromboembolism / diagnosis
  • Thromboembolism / mortality
  • Thromboembolism / prevention & control*
  • Time Factors
  • Treatment Outcome
  • Ventricular Dysfunction, Left / diagnosis
  • Ventricular Dysfunction, Left / drug therapy*
  • Ventricular Dysfunction, Left / mortality
  • Ventricular Dysfunction, Left / physiopathology
  • Ventricular Function, Left*
  • Warfarin / administration & dosage*
  • Warfarin / adverse effects

Substances

  • Anticoagulants
  • Warfarin