Incidence and predictors of left ventricular thrombus after ST elevation myocardial infarction as detected by magnetic resonance imaging

Background

Left ventricular (LV) thrombus formation is a concerning complication of ST elevation myocardial infarction (STEMI). The aim of the current study was to evaluate the incidence of LV thrombus after STEMI using echocardiography and cardiac magnetic resonance imaging (CMR) and to characterize clinical predictors for thrombus formation.

Methods

We evaluated 187 consecutive patients without known prior coronary disease, who underwent primary PCI for STEMI. All patients underwent echocardiographic evaluation as well as CMR during their index hospitalization. Clinical and echocardiographic characteristics were available for all patients and were included in multivariable logistic regression model in order to identify predictors for thrombus formation.

Results

Upon CMR, LV thrombus was present in 17 patients (9%), all of which had an anterior wall MI with a reduced ejection fraction (EF≤45%), thus the prevalence of LV thrombus in anterior MI based on CMR was 18%. Of these, echocardiography demonstrated an LV thrombus in only 6 patients (35%). Accordingly, the sensitivity of 2D-echo in demonstrating LV thrombus among patients was only 35% with a NPV of 85%. Multivariate logistic regression model revealed that higher level of CRP during hospitalization is robust independent predictor of LV thrombus in STEMI patients [OR 1.03; 95% CI 1.006-1.055, p=0.013].

Conclusions

CMR is superior to echocardiography in detecting the presence of an LV thrombus and should be considered in all patients with anterior STEMI and reduced ejection fraction. Elevated levels of CRP are an independent predictor for LV thrombus formation.