Left ventricular thrombosis and arterial embolism after thrombolysis in acute anterior myocardial infarction: predictors and effects of adjunctive antithrombotic therapy

Abstract

The prevalence of left ventricular (LV) thrombosis and incidence of arterial embolism after acute anterior myocardial infarction (AAMI) treated with streptokinase 1.5 x 10(6) IU intravenously was studied in 136 patients enrolled consecutively in five cardiological centres. Adjunctive antithrombotic therapy was administered according to the routine of each centre. Thrombus formation was studied by two-dimensional echocardiography, and events of arterial embolism recorded. LV thrombosis was found in 37 (27.2%) of the patients. In a subgroup of 53 patients receiving post-thrombolytic therapy with acetylsalicylic acid only, a thrombus developed in 14 (26.4%). The thrombus prevalence among patients given high-dose heparin was significantly lower than among those receiving either low-dose heparin or no heparin (4/30 vs 33/106, P = 0.045). Logistic regression analysis suggested that severe LV wall motion abnormality (P < 0.001) and avoidance of treatment with high-dose heparin (P = 0.023) were independent predictors of LV thrombus formation. Only one patient (0.7%) suffered arterial embolism (ischaemic stroke). In conclusion, LV thrombosis is frequent after thrombolytic therapy for AAMI, and impaired LV wall motion represents an independent predisposing factor. Low-dose heparin and acetylsalicylic acid seem less effective for LV thrombus prophylaxis than high-dose heparin. The incidence of arterial embolism is low.