In patients who underwent mitral transcatheter edge-to-edge repair (TEER), a greater than 10% change in estimated glomerular filtration rate (eGFR) was associated with differences in survival at one year, according to a study using data from the STS/ACC TVT Registry published in Structural Heart.

Including 48,472 patients undergoing mitral TEER between 2013 and 2022, Parth N. Patel, MD, et al., evaluated the association between improved renal function (≥10% increase in eGFR), unchanged renal function and worsened renal function (≥10% decrease in eGFR) following the procedure and one-year survival. The study population had a mean age of 78 years, was 86% White and 46% female, and had a mean baseline eGFR of 57.7 ± 21.7 ml/min/1.73 m².

Overall, 15.7% of patients saw improved renal function and 13.7% exhibited worse renal function post mitral TEER. There was a strong association between worsened kidney function and several patient factors including cardiogenic shock within 24 hours, age greater than 80 years, Black race, diabetes, heart failure within two weeks and female sex. "Patients presenting with cardiogenic shock in the 24 hours before the procedure were at greatest risk for a decrease in eGFR following [mitral TEER]," write the authors. "Improvements in eGFR were more likely to be seen in patients with higher hemoglobin levels at baseline."

Improved renal function was associated with a decreased risk of one-year mortality (adjusted hazard ratio 0.77; 95% CI 0.69-0.86, p<0.001) while worsened renal function saw an increased risk of one-year mortality (adjusted hazard ratio 2.85; 95% CI 2.64-3.08, p<0.001) when compared to patients with no change in kidney function.

"In patients who experienced worsened renal function, we observed that the procedure was more likely to be complicated by major or life-threatening bleeding, cardiac arrest, cardiac perforation, or unplanning cardiac or vascular surgical interventions," add the authors. "...Further research is needed to better understand the patients in whom [mitral TEER] is most likely to be successful, as procedure-related complications and subsequent worsening of renal function appear to confer a greater risk of [one-year] mortality."