Prognostic value of left atrial volume index in patients with rheumatic giant left atrium

Abstract

Abstract Background Giant left atrium (GLA), conventionally defined as an anteroposterior diameter of more than 65 mm, is a rare condition mostly resulted from rheumatic mitral valve disease. Assessment of left atrial volume index (LAVI), in place of LA diameter, may have important prognostic implications in rheumatic GLA patients, incremental to clinical and additional imaging parameters. Purpose This study investigated whether initial assessment of LAVI is associated with short-term outcomes in rheumatic GLA patients who did not undergo surgery. Methods This was a single-center, prospective cohort study in 58 patients with definite rheumatic heart disease and echocardiographic-confirmed GLA who refused valve surgery and/or LA reduction procedure. Assessment of clinical, laboratory, echocardiography, and CT angiography thorax with contrast were performed on their first hospital admission. The study population was subdivided based on a LAVI value of 254 mL/m², following the prior ROC curve analysis. Both groups were followed for up to 17 months. The primary endpoint was all-cause mortality. The association between variables and all-cause mortality was analyzed using the Kaplan-Meier curve and Cox proportional hazard regression models. Results A total of 54 out of 58 patients (age 46 ± 11 years; 90.7% women) were included. At baseline, patients with LAVI ≥ 254 mL/m² exhibited significantly higher NT-proBNP level, reduced estimated glomerular filtration rate (eGFR), lower TAPSE, higher systolic pulmonary arterial pressure (sPAP), larger LA diameter, and more prone to atrial fibrillation and LA appendage aneurysm, rather than patients with LAVI < 254 mL/m² (all p<0.05). During a median follow-up of 12 (8–17) months, 11 (20.4%) patients died. Patients with LAVI ≥ 254 mL/m² demonstrated significantly higher mortality rates at 3-, 6-, and 12-months follow up (4%, 6%, and 16%, respectively) when compared with patients with LAVI < 254 mL/m² (2%, 2% and 4%, respectively, log-rank p=0.03). LA appendage aneurysm [hazard ratio (HR): 4.17; 95% confidence interval (CI): 1.15–6.52; p=0.035] and LAVI (HR: 1.07; 95% CI: 1.05–1.1; p=0.042) were independently associated with all-cause mortality. The addition of LAVI to a clinical model (including eGFR, NT-proBNP, LA diameter, cardiogenic shock, echo signs of chambers compression, and LA appendage aneurysm by CT) was associated with significant increase in the X² value (X² difference = 7.19; p<0.001), suggesting the incremental prognostic value of LAVI in patients with rheumatic GLA. Conclusions LAVI is independently associated with all-cause mortality in rheumatic GLA patients not undergoing surgery and provides incremental prognostic value over clinical and imaging variables for short-term survival. LAVI may therefore be useful in the risk stratification of patients with rheumatic GLA and optimize timing of surgical intervention.Baseline characteristics of the studyPrognostic value of LAVI on mortality