Acute Renal Failure After MitraClip Implantation in Patients with Severe Mitral Regurgitation

Background: Acute kidney injury (AKI) is well known adverse event after cardiac surgery, especially after Mitral Valve surgery. There is limited on AKI related to percutaneous mitral valve repair (PMVR). Our aim was to identify the incidence and the predictive factors for acute renal failure in patients after MitraClip procedure, and the potential impact of AKI and mortality.

Methods: In this retrospective observational study we studied a cohort of 163 patients who underwent MitraClip in Hadassah Medical Center and Kaplan Medical Center, Israel. According to the recent guidelines, AKI is defined as an increase of serum creatinine (sCr) of ≥ 0.3 mg/dl or ≥ 1.5×baseline creatinine.

Results: The study population included 163 patients with moderate to severe or severe MR on optimal medical treatment. 5 patients underwent re-do MitraClip implantation. 81.2% of the patients were with NYHA III or IV. The mean EUROSCORE II was 10.88. After the procedure there was significant reduction of the MR from 3.93 to 2.193 (p<0.001).

47 patients developed AKI. In our population, no patients who developed AKI needed hemodialysis and the AKI was reversable in all the cases.

Statistically significant correlation between several risk factors and developing of AKI was demonstrated: higher baseline creatinine, younger patients, male sex, the severity of the MR after the procedure, baseline hemoglobin, additional intravenous furosemide after the procedure, and patient who underwent re-do procedures. Multi-variant logistic regression showed that the most significant risk factors for developing AKI in our cohort were younger age(p=0.004), low baseline GFR(<30)(p=0.37), low baseline hemoglobin levels(p<0.001), and the severity of the mitral regurgitation after the procedure(p=0.008).

Conclusions: The incidence of AKI after PVMK was 28.8%. Age, sex, baseline creatinine, baseline hemoglobin, severity of the MR after the procedure, re-do procedures, and additional furosemide after the procedure showed strong correlation with AKI.