title: Comparison of the usefulness of enoxaparin versus warfarin for prevention of left ventricular mural thrombus after anterior wall acute myocardial infarction.
abstract: Left ventricular (LV) thrombus is one of the most common complications in patients with anterior acute myocardial infarction (AMI) and LV dysfunction. Although anticoagulation is frequently prescribed, data regarding the appropriate drug, duration, risks, and effect on echocardiographic indices of thrombus are lacking. Moreover, given the difficulty in obtaining adequate anticoagulation with warfarin, it is possible that short-term treatment with a more predictable agent would be effective. We randomized 60 patients at high risk of developing LV mural thrombus (anterior acute myocardial infarction with Q waves and ejection fraction≤40%) to receive either enoxaparin 1 mg/kg (maximum 100 mg) subcutaneously every 12 hours for 30 days or traditional anticoagulation (intravenous heparin followed by oral warfarin for 3 months). Clinical evaluations and transthoracic echocardiograms were obtained at baseline, in-hospital, and at 3.5 months. There were no differences between the groups regarding baseline demographics, acute echocardiographic findings, and in-hospital outcomes. The length of hospital stay tended to be shorter for the enoxaparin group (4.6 vs 5.6; p=0.066) and the corresponding hospital costs ($25,837 vs $34,666; p=0.18). At 3 months, bleeding and thromboembolic events were rare and similar between enoxaparin and warfarin groups. Although more patients had probable mural thrombus in the enoxaparin group compared with warfarin at 3.5 months (15% vs 4%; p=0.35), this was not significantly different. In conclusion, the use of enoxaparin tends to shorten hospitalization and lower cost of care. However, at 3.5 months, there appears to be numerically higher (but statistically insignificant) rates of LV thrombus in the enoxaparin group.
authors.affiliation: Cardiovascular Services, Detroit Medical Center Heart Hospital, Detroit, Michigan.
authors.forename: Derek C
authors.initials: DC
authors.lastname: White
authors.affiliation: Cardiovascular Services, Detroit Medical Center Heart Hospital, Detroit, Michigan. Electronic address: cgrines@dmc.org.
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Grines
authors.affiliation: Pharmacy, Community Health Center of Branch County, Coldwater, Michigan.
authors.forename: Lorelei L
authors.initials: LL
authors.lastname: Grines
authors.affiliation: Ministrelli Women's Heart Center, William Beaumont Hospital, Royal Oak, Michigan.
authors.forename: Pamela
authors.initials: P
authors.lastname: Marcovitz
authors.affiliation: Cardiac Catheterization Labs, University of Colorado Denver, Aurora, Colorado.
authors.forename: John
authors.initials: J
authors.lastname: Messenger
authors.affiliation: Cardiovascular Services, Detroit Medical Center Heart Hospital, Detroit, Michigan.
authors.forename: Theodore
authors.initials: T
authors.lastname: Schreiber
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D056988:Anterior Wall Myocardial Infarction / Q000150:complications* / Q000628:therapy; D000925:Anticoagulants / Q000627:therapeutic use*; D017984:Enoxaparin / Q000627:therapeutic use*; D005260:Female; D006331:Heart Diseases / Q000209:etiology / Q000517:prevention & control*; D006493:Heparin / Q000627:therapeutic use; D017721:Hospital Costs; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D013318:Stroke Volume; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D014859:Warfarin; D006493:Heparin