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

The prevalence of left ventricular (LV) thrombosis and incidence of arterial embolism after acute anterior myocardial infarction (AAMI) treated with streptokinase 1.5 × 106 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.