Role of Echocardiographic Left Atrial Volumetric/Mechanical Coupling Index (LACI) to Predict Postoperative Atrial Fibrillation or Flutter Following Transcatheter Aortic Valve Replacement

New-onset atrial fibrillation (NOAF) is a common complication of both surgical or transcatheter aortic valve replacement (AVR) and is associated with increased mortality, stroke, major bleeding, pacemaker implantation, and a longer hospital stay. Enlargement of the left atrium (LA) is known as an echocardiographic predictor of NOAF. In addition, the prognostic role of LA function in patients undergoing AVR have been explored in small patient series by speckle tracking echocardiography, with reduced applicability in clinical practice. LA volumetric/mechanical coupling index (LACI) is the ratio between LA volume-index (LAVi) to Tissue-Doppler myocardial velocity at atrial contraction (TDI-a’). TDI-a’ is an established measure of LA mechanics easily measurable in routine practice without requiring dedicated software or any additional image acquisition. LACI has been show to predict AF in general population. This study evaluated the predictive value of LACI for NOAF after isolated TAVR in a retrospective cohort of 173 patients, analyzing clinical, demographic, procedural, biohumoral and echocardiographic data. Patients who developed NOAF (7%) exhibited significantly higher LACI values (mean: 9.89 ± 4.4 vs. 5.88 ± 3.13, p = 0.0012) and LA volumes (LAVi: 56.0 ± 12.0 ml/m² vs. 44.2 ± 14.3 ml/m², p = 0.006). Additionally, a ROC analysis identified an optimal LACI with TDI-a’ average threshold of 6.17, with an AUC of 0.80, sensitivity of 67% and specificity of 63%, underscoring its predictive utility. These findings highlight the feasibility of using LACI, a straightforward and cost-effective echocardiographic parameter, for early risk stratification of NOAF in TAVR candidates. Incorporating this metric in preoperative assessments may guide postoperative management strategies. Further prospective studies are warranted to validate these findings and refine therapeutic interventions aimed at mitigating NOAF-related complications.