Long term follow up of patients with anterior myocardial infarction complicated by left ventricular thrombus in the thrombolytic era.

OBJECTIVES

To examine the appearance and resolution of left ventricular thrombi and to study the relation between thrombus and mortality during long term follow up after anterior myocardial infarction.

DESIGN

Ninety nine consecutive patients were prospectively studied until the last included patient had been followed for one year. Streptokinase and aspirin were used routinely, anticoagulants only after a decision by the attending physician. Echocardiography was performed within 3 d of admission, before discharge, and after one, three, and 12 months.

SETTING

Umeå University Hospital, a teaching hospital in Northern Sweden.

MAIN OUTCOME MEASURES

Left ventricular thrombus, segmental myocardial function, and mortality during follow up.

RESULTS

Thirty patients (30%) had a thrombus on discharge. One month, three months, and 12 months after hospital discharge, the thrombus had resolved in 81%, 84%, and 90% of the patients, respectively. The proportion of resolved thrombi at one month was high irrespective of whether anticoagulants were given (10/11, 91%) or not (12/16, 75%), P = 0.4. New thrombi appeared in 12 patients after discharge and resolution and reapperance of thrombi continued during the follow up period. Patients who developed a thrombus during the hospital stay (n = 44, 44%) had more extensive myocardial dysfunction on discharge (P < 0.001) and significantly higher mortality during the follow up period than those without a thrombus (23% v 7%, P < 0.01).

CONCLUSIONS

With routine thrombolytic and aspirin treatment of anterior myocardial infarction, left ventricular thrombi usually resolve during the first month after hospital discharge. Appearance and resolution of thrombi continue, however, in a significant proportion of the patients during long term follow up. A left ventricular thrombus during the initial hospital stay is associated with high long term mortality.