Abstract 19640: The Course of Left Ventricular Thrombus Formation following Primary Percutaneous Coronary Intervention as Assessed by Cardiac Magnetic Resonance Imaging in Acute Myocardial Infarction
Background: Left Ventricular (LV) thrombus formation is a well-recognized complication of acute myocardial infarction (MI). Its detection is clinically relevant in view of potential life-threatening complications such as systemic embolic events. The course of development and disappearance of LV thrombus following acute MI is unknown in the modern era of primary percutaneous coronary intervention (PCI) and dual anti-platelet therapy. We assessed the predictors of LV thrombus formation in the setting of primary PCI using contrast-enhanced magnetic resonance imaging (CE-MRI) during a 4 month follow period.
Methods: In a prospective cohort study of a total of 142 patients treated by primary PCI for acute MI, CE-MRI was obtained at baseline and 4 months to assess the presence of mural thrombus formation. On admission, all patients received heparin, aspirin and clopidogrel.
Results: LV thrombus was visualized in 8.5% (n=12) of the patients on CE-MRI performed at 3.5 +/− 1.3 days after acute MI. Anterior infarction (p=0.002), infarct size (p<0.05) and the presence of microvascular obstruction (p=0.04) were independently associated with the presence of LV thrombus on baseline MRI. At discharge, 6 of 12 patients received additional warfarin (treating physician's choice). Follow-up MRI performed at 4 months did not show a significant difference in the persistence of LV thrombi when comparing patients with or without additional warfarin. (p=0.67) During 24-month clinical follow-up, in none of the 142 patients a systemic embolic event was witnessed.
Conclusion: Predictors of LV thrombus formation after PCI-treated acute MI are infarct location, infarct size and the presence of microvascular obstruction. The incidence of LV thrombus in these patients is relatively low and in the present cohort no systemic embolic events were witnessed, also in patients with a documented LV thrombus and no warfarin-treatment. Also, warfarin did not show any additional benefit with regard to resolution of LV thrombus. This challenges current guidelines recommending additional warfarin in acute MI patients with LV thrombus treated by primary PCI.
- © 2010 by American Heart Association, Inc.