Detection of left ventricular thrombus in newly diagnosed heart failure patients: diagnostic accuracy of 2D transthoracic echocardiography compared with cardiac MRI in a Kenyan cohort

TL;DR

This study compares the accuracy of 2D transthoracic echocardiography and cardiac MRI in detecting left ventricular thrombus in heart failure patients in Kenya.

Contribution

The study provides evidence on the diagnostic accuracy of 2D TTE for LVT detection in a resource-limited setting where MRI is scarce.

Findings

11% of patients with severely reduced LVEF had left ventricular thrombus detected by CMR.

2D TTE had a sensitivity of 0.72 and specificity of 0.78 for LVT detection.

2D TTE showed an excellent negative predictive value of 0.98 for excluding LVT.

Abstract

Left ventricular thrombus (LVT) is a recognized complication of severe left ventricular (LV) systolic dysfunction. While cardiac magnetic resonance (CMR) Imaging is considered the gold standard due to its high sensitivity and specificity for detecting LVT, its availability remains limited in Sub-Saharan Africa. In contrast, 2D transthoracic echocardiography (TTE) is more accessible and commonly used in clinical practice. This study aimed to determine the incidence of LVT in patients with a left ventricular ejection fraction (LVEF) of less than 35% from any etiology, and to compare the diagnostic accuracy of TTE against CMR for its detection.

This prospective, cross-sectional study was conducted at the Aga Khan University Hospital Nairobi (AKUH, N). The study included patients aged 18 years and above with new onset heart failure symptoms and severely reduced LVEF of ≤ 35%. The study was conducted between January 2021 and December 2023. Patients underwent non-contrast 2D TTE and CMR within a 14-day interval. Diagnostic accuracy of 2D TTE was assessed using sensitivity, specificity, and predictive values.

A total of 100 patients were included in the final analysis. The median age of participants was 58.0 years (IQR: 47.0–67.0). The median LVEF was 30% (IQR: 20–33). The median time between 2D echocardiography and cardiac MRI was 10 days (IQR: 1–12). LVT was detected in 11 patients (11%) on CMR. A significantly higher proportion of those with LVT had an ischemic etiology (n = 10, 90.9%) (p < 0.05). Participants with LVT had a lower LVEF (19%, IQR: 14–31) and larger left ventricular internal diameters (IQR 62 mm, IQR: 55–77.5) (p- value < 0.05). Among those with LVT, 73% (n = 8) had it detected by both diagnostic modalities. The 2D TTE’s sensitivity and specificity for detecting LVT were 0.72 and 0.78, respectively, with an excellent negative predictive value of 0.98.

11% of patients were found to have LVT on CMR. Patients with ischemic cardiomyopathy, significantly reduced LVEF, and a dilated LV, were identified as being at the highest risk for developing LVT. 2D TTE showed an excellent negative predictive value in excluding the presence of LVT.

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