Incidence and Predictors of Left Ventricular Thrombus Formation After Acute Myocardial Infarction With ST-Segment Elevation.

Abstract

Background and objective Our prospective study aimed to evaluate the frequency and risk factors of left ventricular thrombus (LVT) occurring after acute ST-segment elevation myocardial infarction (STEMI) in the era of primary percutaneous coronary intervention (PCI). Methods Our study included 131 patients diagnosed with acute STEMI who were followed up and treated. The presence of the thrombus was determined by transthoracic echocardiography (TTE). Study patients were evaluated as cases of thrombus (+) and thrombus (-). The relationship of electrocardiographic measurements such as the number of leads with pathological Q waves, ST segment deviation score, QT dispersion, and echocardiographic measurements such as ejection fraction (EF), end-systolic and end-diastolic volumes, and wall motion score index (WMSI) with LVT was investigated. LVT risk factors were identified. Results The median age of the study patients was 59.7 ± 11.7 years, and 84.7% were male. The incidence of LVT was 17.6% (23 patients). While the anterior STEMI rate was 86.9% in the thrombus (+) group, it was 50.9% in the thrombus (-) group (p<0.001). While WMSI was 2.1 ± 0.44 in the thrombus (+) group, it was calculated as 1.40 ± 0.31 in the thrombus (-) group (p<0.001). In the thrombus (+) group, EF was found to be lower, end-systolic and end-diastolic volumes were higher, and the rate of moderate and severe mitral regurgitation and the rate of aneurysmatic segment detection were higher. LVT had a moderate correlation with WMSI (r: 0.613; p<0.001), the presence of an aneurysmatic segment (r: 0.549; p<0.001), and EF (r: -0.514; p<0.001). Presentation with anterior STEMI (odds ratio [OR]: 4.266; p<0.001), WMSI (OR: 7.971; p=0.012), the number of leads with pathological Q waves detected at discharge (OR: 3.651; p=0.009), the presence of an aneurysmatic segment (OR: 2.089, p=0.009), and EF (OR: 1.129, p=0.006) were identified as independent risk factors of the presence of LVT. The area under the curve for WMSI was found to be 0.910 (95% CI: 0.852-0.968). A WMSI cut-off of 1.56 identified LVT with 91% sensitivity and 70% specificity (Youden index: 0.617). Conclusion In the primary PCI era, LVT incidence after acute STEMI is still significant. Anterior STEMI, the number of leads with pathological Q waves detected at discharge, WMSI, aneurysm formation, and low EF are independent risk factors for LVT. Among these risk factors, the variable with the highest diagnostic power is WMSI.