Strain characterization of multi-chamber cardiac dysfunction and associated prognosis in patients undergoing TAVR for severe AS.

BACKGROUND

In patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR), myocardial dysfunction may extend beyond the left ventricle and remain underrecognized by conventional severity classification paradigms. Strain echocardiography allows early detection of subclinical dysfunction across cardiac chambers, potentially enhancing prognostic stratification.

METHODS

We retrospectively analysed 234 patients with severe AS undergoing TAVR who had echocardiograms suitable for strain analysis. Left ventricular (LV), left atrial (LA), and right ventricular (RV) strain values were quantified pre- and post-TAVR. Chamber dysfunction was defined using consensus strain thresholds, and multichamber impairment (MCI) was defined by dysfunction in two or more chambers. A modified damage staging system incorporating strain data was compared to an established model. The association between chamber impairment and all-cause mortality was explored.

RESULTS

Strain-defined chamber impairment was common, with 29% of patients exhibiting MCI. LA dysfunction was the most frequent isolated abnormality, accounting for 88% of single chamber impairment. Modest improvement was observed post-TAVR, predominantly in LV global longitudinal strain (+ 1.8 ± 3.5%, p < 0.01). MCI was associated with higher rates of atrial fibrillation, chronic kidney disease, and mitral/tricuspid regurgitation. At 12-month follow-up, patients with three-chamber impairment had significantly increased mortality risk (HR 6.84, 95% CI 1.77-26.4, p = 0.005). The modified staging system reclassified 27% of patients into higher risk categories but did not significantly improve predictive accuracy over the established model.

CONCLUSION

Multichamber dysfunction, particularly involving the LA, is prevalent in patients undergoing TAVR and confers a higher early mortality risk. While the addition of strain data improves damage detection, its incremental prognostic value over conventional models appears modest in this cohort. Larger studies are required to explore this further. Comprehensive strain imaging may nonetheless identify patients requiring closer surveillance and targeted post-TAVR therapy.