Characterisation of acute ischemic stroke in patients with left ventricular thrombi after myocardial infarction

Abstract

Acute ischemic stroke (AIS) is a feared complication in post-acute myocardial infarction (AMI) patients who develop left ventricular (LV) thrombus. There is limited data available on the incidence of stroke in this population, and characterisation of stroke subtypes has not been previously reported. Our study aims to evaluate the incidence of AIS in post-AMI patients with LV thrombus and to characterise the pattern of stroke subtypes. We screened 5829 patients with echocardiogram reports containing the "thrombus" keyword from August 2006 to September 2017. AIS that occurred after LV thrombosis was captured and relevant clinical data was collected. We identified 289 post-AMI patients with acute LV thrombus formation. Mean age was 59.3 ± 13.4 years. AIS occurred in 34 patients (11.8%), median duration of 20.5 days (IQR = 5.5-671.8) after LV thrombosis. Despite initial thrombus resolution, nine (5.2%) encountered AIS subsequently. Cardioembolic stroke subtype was identified in 76.5% of AIS, whilst 14.7% was small vessel disease and 8.8% was of large artery atherosclerosis subtype. Presence of thrombus protrusion (HR 3.04, 95% CI 1.25-7.41, p = 0.01), failure of initial thrombus resolution (HR 3.03, 95% CI 1.23-7.45, p = 0.02) and thrombus recurrence (HR 4.20, 95% CI 1.46-12.11, p < 0.01) were significant independent predictors for stroke. Incidence of AIS in this Asian population of post-AMI patients with LV thrombus was 11.8%. Duration of anticoagulation may need to be individualised for patients with higher risk for stroke occurrence after LV thrombosis.

Keywords: Acute ischemic stroke; Acute myocardial infarction; Anticoagulation; Cardioembolism; Left ventricular thrombus.