Prognostic value of left atrial stiffness index in adults with repaired coarctation of aorta

Echo-derived left atrial (LA) stiffness index improves prognostication in patients with heart failure preserved ejection fraction but has not been studied in adults with repaired coarctation of aorta (COA). We hypothesized that, among adults with COA, those with high LA stiffness index would have worse disease severity indices [peak VO₂, NT-proBNP, and right ventricular to pulmonary artery (RV-PA) coupling], heart failure hospitalization, and all-cause mortality.

LA stiffness index was estimated using the baseline echocardiogram as the quotient of septal E/e′ and LA reservoir strain (E/e′/LARS). Using the median septal LA stiffness index as the cut-off, patients were divided into high LA stiffness index (LA stiffness index >0.28) vs. low LA stiffness index groups (LA suggests index ≤0.28). The study comprised of 729 patients [age 36 ± 16 years; males 437 (60%)]. LA stiffness index correlated with RV-PA coupling (r = −0.56, P < 0.001), NT-proBNP (r = 0.62, P < 0.001), and predicted peak VO₂ (r = −0.51, P < 0.001). High LA stiffness index was associated with heart failure hospitalization (adjusted HR 3.17, 95% confidence interval (CI) 1.84–7.36, P = 0.007) and all-cause mortality (adjusted HR 2.81, 95% CI 1.28–12.32, P = 0.005). LA stiffness index had superior prognostic performance for predicting 5-year risk of heart failure hospitalization (AUC 0.803, 95% CI 0.756–0.849, P < 0.001) and all-cause mortality (AUC 0.786, 95% CI 0.742–08.30, P < 0.001) compared with conventional echocardiographic indices of left heart diastolic function.

LA stiffness index improves prognostication in adults with COA and can potentially be used to guide timing of intervention or monitor response to therapy.