Incidence and Predictors of Left Ventricular (LV) Thrombus after ST-Elevation Myocardial Infarction (STEMI) in the Holy Capital of Saudi Arabia

BACKGROUND: Patients with acute myocardial infarction (AMI) especially those with large MI (myocardial infarction) as identified by ST elevation in multiple contiguous ECG leads or anterior MI, may suffer significant myocardial damage leading to impaired wall motion and contractility which may lead to the formation of left ventricular thrombus (LVT) in the patient. This study was aimed to establish the incidence of LV thrombus and determine the predictors associated with the formation of LV thrombus in patients with AMI. METHODS: This retrospective study was held at the only cardiothoracic centre of Makkah, which provides tertiary level cardiac services. A total of 3084 consecutive patients with acute MI between 2016 and 2019 were identified and divided into two groups i.e. group I (with LVT) and group II (without LVT). The case notes, echocardiography data and cardiac catheterization lab records were reviewed to identify patients with LV thrombus. Regression analysis was employed to evaluate the predictors responsible for the formation of LV thrombus. RESULTS: The overall incidence for LV thrombus was determined as 8.4% (n = 260/3084), while in the subpopulation of pilgrims, it was 8.2% (83/1001). Mean age for patients with and without LVT was 54 ± 11 years vs 56 ± 12 years (p < 0.003), respectively. There was no significant difference between the two groups with respect to gender, diabetes, hypertension, smoking, Arabic speaking or BMI>30. Coronary thrombus aspiration was utilized in 17% vs 12% (p < 0.023) patients with LVT and without LVT, respectively. It was observed that the patients with cardiac arrest tend to develop more LVT i.e. 8.5% vs 5.2% (p < 0.033). However, LV thrombus formation was significantly associated with anterior STEMI with incidence of LVT reaching 13.4% and low ejection fraction (all MI types) i-e. 32 ± 9% vs 42 ± 11%, with p < 0.000 for both independent predictors. CONCLUSIONS: LV thrombus is a relatively common occurrence in patients with acute MI, especially those with anterior STEMI and low ejection fraction<30%. Appropriate imaging studies are required for all acute MI patients in order to ascertain the presence or absence of LV thrombus as it has major influence on further management.