Left ventricular mural thrombus after anterior ST-segment-elevation acute myocardial infarction in the era of aggressive reperfusion therapy ??? still a frequent complication

BACKGROUND

Left ventricular mural thrombus (LVMT) is a well-known complication of anterior ST-elevation acute myocardial infraction (AMI). It remains unknown how modern therapies have impacted on its occurrence.

OBJECTIVES

To define the frequency of LVMT among contemporary patients with anterior ST-elevation AMI, the clinical and echocardiographic predictors of LVMT formation, and the intermediate-term outcomes of patients with LVMT.

METHODS

We retrospectively analysed patients (in the years 1997-2002) with a diagnosis of anterior ST-elevation AMI and no prior AMI, and who underwent a thorough echocardiographic assessment within 72 h of admission. Stepwise logistic regression analysis was used to define predictors of LVMT formation. Survival was calculated by the Kaplan-Meier product-limit method.

RESULTS

Of the 153 patients with complete data, LVMT was detected in 36 (23.5%). There were no significant differences in baseline demographic and clinical variables between LVMT and non-LVMT patients, or in treatments (all patients received reperfusion treatment). The mean wall motion score index was higher in LVMT than non-LVMT patients (0.88+/-1.79 versus 0.65+/-0.36, respectively; P=0.01), indicating worse cardiac systolic function. LVMT patients were treated with warfarin for 3-6 months. The incidence of death was similar between the groups (11.1% for LVMT patients versus 12.8% for non-LVMT patients, P=0.79) over a mean follow-up of 71-72 months. The only independent predictor found for LVMT occurrence was worse regional wall motion of the apex (odds ratio, 2.04, 95% confidence interval, 1.39-3.03; P<0.001).

CONCLUSIONS

In the contemporary 'real-world scenario', despite aggressive reperfusion treatment and anti-aggregant use, the incidence of LVMT remained high after anterior ST-elevation AMI. LVMT was not related to increased intermediate-term mortality when patients were treated with warfarin, and the only predictor of LVMT occurrence was regional function of the apex.

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.