Abstract 4144585: Association of renal function with mortality and heart failure hospitalization rates after Transcatheter Mitral Valve Edge to Edge Repair

Background: Transcatheter edge to edge repair (TEER) is an established treatment for patients with symptomatic severe functional MR on optimal medical therapy or severe symptomatic primary MR and high surgical risk. Renal dysfunction is associated with adverse outcomes but the threshold at which risks rise are uncertain. Aim To determine the association of estimated glomerular filtration rate (eGFR) with adverse outcomes in patients undergoing TEER for severe symptomatic mitral regurgitation (MR) in Ontario, Canada. Methods: This was a population-based retrospective cohort study using linked administrative datasets of patients who underwent TEER in Ontario, Canada, between 2011 and 2023. The key exposure was eGFR, which was modeled using restricted cubic splines. Outcomes were 1-year mortality, cardiovascular mortality (CV) and heart failure hospitalization (HF). Cause-specific hazards regression was used to model the association between eGFR and outcomes, utilizing eGFR 30ml/min/1.73m2 as the reference value. Results: We studied 2076 patients, of whom 294 (14.2%) had eGFR <30ml/min/1.73m2 and 841 (40.5%) had eGFR 30-60ml/min/1.73m2. The incidence at one year was 16.8% for all-cause mortality, 11% for CV mortality and 14.2% for HF hospitalizations. The Figure illustrates that the predicted incidence of adverse outcomes increases with lower eGFR, with subtle differences in patterns of change in risk at lower eGFR levels such that all-cause mortality and CV mortality begin to rise rapidly at eGFR values ≤30ml/min/1.73m2, while HF hospitalization increases linearly at eGFR ≤50ml/min/1.73m2. Conclusions: There was a progressive increase in all-cause, CV mortality and HF hospitalization after TEER for patients with lower eGFR, particularly those with values <30 ml/min/1.73m2. This data can inform patient discussions and guide post-procedural follow-up.