Impact of dialysis on structural valve deterioration post TAVI

Background

Patients with end-stage kidney disease requiring dialysis represent a particularly high-risk population among those undergoing transcatheter aortic valve implantation (TAVI) for aortic stenosis. Prior studies have suggested poorer outcomes for dialysis patients, with higher rates of mortality and complications including structural valve deterioration.

Purpose

Valve durability is a key consideration for all TAVI patients and this study aims to evaluate the incidence and progression of SVD in dialysis patients and examine its association with clinical outcomes.

Method

An initial cohort of 22,447 eligible patients was identified on the Australasian Cardiac Outcomes Registry (ACOR), with 428 receiving dialysis. A 1:2 propensity score matching model was constructed using baseline demographic and clinical variables to balance covariates between groups. SVD was defined according to VARC-3 criteria as an increase in transvalvular gradient and/or worsening aortic regurgitation relative to post-procedural baseline. Echocardiographic assessment windows were predefined as 14-60 days (30-day analysis) and 9-15 months (12-month analysis). Conditional logistic regression was then used to evaluate the association between dialysis and SVD at 30 days and 12 months. Kaplan-Meier survival analysis and Cox proportional hazards modelling were performed to assess 12-month mortality.

Results

After propensity matching, 760 patients were included in the 30-day SVD analysis. 17 SVD events occurred within 30 days. Dialysis was associated with significantly increased odds of early SVD (OR 3.50, 95% CI ~1.1–11.4, p=0.03).

At 12 months, 406 patients had eligible echocardiographic follow-up, with 14 SVD events observed. Dialysis was associated with a numerically increased risk of SVD (OR 3.24, 95% CI 0.29–36.63; p=0.34), although this did not reach statistical significance. Interpretation is limited by low event rates and significant follow-up attrition.

For 12-month mortality, 816 matched patients were analysed and 80 deaths observed. One-year survival was 96.4% (95% CI 94.8–98.0%) in non-dialysis patients compared with 91.7% (95% CI 88.4–95.1%) in dialysis patients. Dialysis was associated with a significantly increased hazard of death at 12 months (HR 2.42, 95% CI 1.56–3.76, p<0.001).

Conclusion

In this propensity-matched cohort, dialysis was independently associated with increased early SVD and significantly higher 12-month mortality following TAVI. Although a similar magnitude of association between dialysis and SVD was observed at 12 months, statistical significance was not achieved due to limited event rates and incomplete follow-up These findings suggest that dialysis-related pathophysiologic mechanisms may exert their greatest impact early after valve implantation, though further studies with comprehensive longitudinal follow-up are warranted to clarify long-term structural durability in this population.12-Month Survival post TAVIFor image description, please refer to the figure legend and surrounding text.