Introduction: Lacunar strokes are single, small, subcortical (SSS) infarcts caused by small cerebral vessel blockage. The diagnosis of lacunar strokes relies on presence of risk factors, typical lacunar syndromes, and radiographic confirmation. Though non-lacunar causes such as large artery atherosclerosis (LAA) and cardiac embolism occasionally result in subcortical infarcts, the added utility of transthoracic echocardiogram (TTE) in clinical management of SSS infarcts has not been reported. We hypothesized that TTE would identify potential cardioembolic causes, subsequently changing management in patients with SSS infarcts.
Methods: We performed a retrospective study of a prospective cohort of ischemic stroke patients from August 2012-July 2014 in whom brain MRI and TTE were completed during index stroke admission. We assessed infarct topography and TTE results blinded to stroke subtype and treatment. We defined SSS infarcts as lesions in the corona radiata, basal ganglia, thalamus, or brainstem measuring <1.5 cm. We assessed prevalence of TTE findings: dilated left atrium, patient foramen ovale (PFO), atrial septal aneurysm (ASA), low ejection fraction (EF <35%), and thrombus.
Results: Among 908 patients, 75 (8.3%) met inclusion criteria (mean age 65.46, 53% female, 57% white). Of these patients, 4 had atrial fibrillation by EKG and 5 had symptomatic LAA by vessel imaging. TTE revealed cardiac abnormalities in nearly half of the 66 remaining patients. The most common finding was dilated left atrium (33%), followed by PFO (15%) and ASA (7.5%); 1 patient had thrombus, 1 had atrial myxoma, and another had EF <35%. Anticoagulants were prescribed on the basis of TTE findings in 4.5% (95% CI [1.6-12.5]) of patients. The final stroke subtype was: 72% lacunar; 8% cardioembolic, 6.7% LAA, 2.7% other determined cause and 10.6% undetermined cause.
Conclusion: TTE findings revealed potential cardioembolic sources in roughly half of patients presenting with SSS infarcts. However, medical management was changed in only 4.5 % of patients. Other medium risk findings did not change management, but warrant further research. Overall, our data suggest that there is a small but potentially important yield of TTE in patients presenting with SSS infarcts.