Association between the E-wave propagation index and left ventricular thrombus formation in systolic heart failure.
BACKGROUND The E-wave propagation index (EPI) has been proposed as a simple risk marker of left ventricular (LV) thrombus (LVT) formation. We sought to investigate the association between EPI and LVT in patients with heart failure with reduced ejection fraction (HFrEF). METHODS This was a retrospective cohort study on 768 patients with HFrEF. The EPI was measured as the velocity time integral of the transmitral E-wave divided by the LV length. The endpoint was LVT formation. Logistic regression was applied to investigate the association between EPI and LVT. Multivariable adjustments were made for age, mitral regurgitation, apical aneurysm, prior myocardial infarction, and LV ejection fraction (LVEF). Area under receiver operating characteristic curves was used to assess the optimal cut-off value for EPI. RESULTS Of 768 HFrEF patients, 24 (3%) had developed LVT. The mean age was 66 years, 73% were men, and the mean LVEF was 28%. EPI was lower among those who had developed LVT (1.1 vs 1.3, p = 0.018), and EPI was significantly associated with LVT formation in univariable logistic regression (OR = 1.16 (1.0-1.3), per 0.1 decrease). This finding was unchanged after multivariable adjustments. The EPI provided an area under the curve of 0.68 with an optimal cutoff of 1.2. This cutoff had a sensitivity of 75%, specificity of 60%, positive predictive value of 6%, and negative predictive value of 99%. Patients with an EPI <1.2 had a four-fold increased risk of LVT (OR = 4.42 (1.73-11.25), p = 0.002). CONCLUSION In patients with HFrEF, the EPI was independently associated with LVT formation. Additionally, an EPI > 1.2 indicates a low likelihood of developing LVT.