Left ventricular thrombosis after anterior myocardial infarction with and without thrombolytic treatment.

Objectives: To examine the incidence of left ventricular thrombus in patients with anterior myocardial infarction, with and without streptokinase treatment. To identify predictors of thrombus development.

Design: Consecutive patients prospectively studied during the hospitalized period. Echocardiography was performed within 3 days of admission and before discharge.

Setting: Umeå University Hospital, a teaching hospital in Northern Sweden.

Subjects: Ninety-nine patients with anterior myocardial infarction of whom 74 were treated with streptokinase.

Main Outcome Measures: Left ventricular thrombus and left ventricular segmental myocardial function.

Results: During the hospital stay, a thrombus developed in 46% (95% confidence interval [CI], 35-57%) of the patients in the thrombolysis group and in 40% (95% CI, 21-59%) of the patients in the non-thrombolysis group. No difference in left ventricular segmental myocardial function was found between the thrombolysis and non-thrombolysis groups at hospital discharge. No embolic events were observed. The occurrence of a left ventricular thrombus at hospital discharge was significantly associated with previous myocardial infarction, peak enzyme levels, left ventricular global and segmental dysfunction and an increased dose of peroral diuretics or use of parenteral diuretics. In a multiple logistic regression model, left ventricular segmental dysfunction was the most important predictor of left ventricular thrombus.

Conclusion: Thrombolytic treatment with streptokinase does not prevent the development of a left ventricular thrombus but the risk of embolic complications is low. The left ventricular segmental myocardial score can be used to assess the risk of thrombus development, also, after thrombolysis.