Differential effect of chronic kidney disease on right-sided extravalvular damage in low-flow, low-gradient aortic stenosis.

OBJECTIVES

In the transcatheter aortic valve replacement (TAVR) era, the presence of low-flow, low-gradient aortic stenosis (LFLG AS) itself does not preclude intervention. However, chronic kidney disease (CKD) and right-sided extravalvular damage (RSED) complicate procedural risk assessment. Both their association with each other and their joint impact on post-TAVR mortality in LFLG AS and across its subtypes remain incompletely characterized.

METHODS

The authors performed a retrospective study of patients with LFLG AS who underwent TAVR between 2019 and 2022, stratified by CKD stage (from no CKD to end-stage renal disease [ESRD]) and LFLG AS subtype (classical vs paradoxical). RSED was defined by greater than or equal to moderate pulmonary hypertension, greater than or equal to moderate tricuspid regurgitation, or right ventricular (RV) systolic dysfunction. Poisson regression models assessed associations between CKD stage and RSED, while multivariable Cox regression models and Wald tests compared mortality across cohorts.

RESULTS

Among 402 patients (137 classical, 265 paradoxical), ESRD was independently associated with RSED and RV dysfunction, whereas earlier CKD stages were not. ESRD was associated with increased RV dysfunction in paradoxical LFLG AS but not in classical LFLG AS. Advanced CKD and RSED were each associated with increased post-TAVR mortality. In paradoxical LFLG AS, combined RSED and advanced CKD were associated with significantly higher mortality than either condition alone. This effect was not observed in classical LFLG AS patients.

CONCLUSIONS

Advanced renal dysfunction is associated with RSED in LFLG AS. In paradoxical LFLG AS, their combination has a possibly multiplicative association with mortality.