Left Atrial Coupling Indexes as New Mortality Predictors in Chronic Chagas Disease

Purpose This study aimed to evaluate the all‐cause mortality predictive value of left atrioventricular coupling indexes in patients with chronic Chagas disease (CD). Methods This single‐center retrospective longitudinal study included 382 patients with chronic CD. The left atrioventricular coupling index (LACI) was defined as the ratio of left atrial (LA) over left ventricular (LV) end‐diastolic volumes. LA volumetric/mechanical coupling index (LAVI/A’) was the ratio of maximum LA volume index over late diastolic mitral annulus velocity. The endpoint was a composite of all‐cause mortality or heart transplant. The associations between LACI or LAVI/A’ and the endpoint independent from clinical, electrocardiographic, and 2D echocardiographic parameters (Model I) or from Model I adjusting variables plus LV and LA strain parameters (Model II) were tested by multivariate Cox‐proportional‐hazards regression. Results After a mean follow‐up of 6.6 ± 2.7 years, 80 patients died and two underwent a heart transplant. LACI was associated with the endpoint in Models I (HR 1.03, 95% CI 1.01–1.05, p = 0.01) and II (HR 1.03, 95% CI 1.01–1.05, p = 0.0008). LAVI/A’ was also associated with the endpoint in Models I (HR 1.08, 95% CI 1.05–1.12, P < 0.0001) and II (HR 1.09, 95% CI 1.05–1.12, P < 0.0001). The area under the ROC curve was larger for LAVI/A’ than LACI (0.87 vs. 0.65, P < 0.0001). The optimal cutoff value for LAVI/A’ was 3.3 mL × s/cm −1 per m 2 (sensitivity 81.7%, specificity 83.7%). Patients with LAVI/A’ ≥ 3.3 at baseline had a 19‐fold higher risk for all‐cause mortality. Conclusion New echocardiographic LA coupling indexes are promising predictors of dismal clinical outcomes in CD.