Multimodal Atrial Cardiomyopathy Phenotypes for Risk Stratification in Severe Aortic Stenosis Undergoing TAVI

Atrial cardiomyopathy (AtCM) is highly prevalent in patients with severe aortic stenosis (AS), even in the presence of preserved left ventricular ejection fraction (LVEF). Structural, functional, and electrical atrial remodeling may differentially influence outcomes after transcatheter aortic valve implantation (TAVI), although their integrated prognostic role remains unclear.

To assess whether multimodal markers of AtCM identify distinct risk phenotypes associated with adverse outcomes after TAVI in patients without prior atrial fibrillation (AF).

We retrospectively analyzed 122 consecutive patients with severe AS, preserved LVEF, and sinus rhythm undergoing TAVI. Structural/functional AtCM (Echo-AtCM Risk) was assessed using indexed left atrial volume (LAVI) and left atrial reservoir strain (LASr), whereas electrical AtCM (ECG-AtCM Risk) was defined according to P-wave duration and morphology. Patients were followed for all-cause mortality, heart failure (HF) hospitalization, and new-onset AF. Prognostic associations were evaluated using multivariable Cox regression analyses.

Mean age was 82.3±5.6 years. High Echo-Risk was present in 54.1% of patients and High ECG-Risk in 19.7%. During a median follow-up of 13.6 months, the composite endpoint of all-cause mortality or HF hospitalization occurred in 39 patients (32.0%), while new-onset AF developed in 17 (13.9%). High Echo-Risk independently predicted death/HF hospitalization (HR 4.17, p=0.008), whereas High ECG-Risk independently predicted incident AF (HR 3.07, p=0.034). Combined profiling identified distinct phenotypes: High Echo/Low ECG predicted HF/death (HR 4.86, p=0.008), Low Echo/High ECG predicted AF (HR 8.99, p=0.004), and combined High Echo/High ECG conferred the worst prognosis (HR 6.23, p=0.015).

Structural, functional, and electrical AtCM represent complementary domains with distinct prognostic implications in AS patients undergoing TAVI. Their integration may refine post-TAVI risk stratification; these exploratory findings require external validation before clinical management can be guided by AtCM phenotype.Keywords: Atrial cardiomyopathy; Aortic stenosis; TAVI; Left atrial strain; Heart failure; Atrial fibrillation.