Long‐term clinical and haemodynamic results after transcatheter annuloplasty for secondary mitral regurgitation

AIMS: The study sought to investigate the long‐term outcome after transcatheter mitral valve annuloplasty for secondary mitral regurgitation (MR). METHODS AND RESULTS: Consecutive patients with symptomatic secondary MR undergoing transcatheter mitral valve annuloplasty with the Carillon device at Leipzig University Hospital between 2012 and 2018 were studied prospectively. Left ventricular (LV) function and MR severity were quantified by standardized echocardiography. 33 patients were included. Mean age was 75 ± 10 years, and 20 patients were women. A Society of Thoracic Surgeons score of 8.1 ± 7.2% indicated high‐risk status. In 24 patients, MR resulted from LV remodelling and dysfunction, eight suffered from left atrial dilatation, and one patient had MR due to combined primary and secondary aetiology. LV ejection fraction at baseline was (median) 38% [inter‐quartile range (IQR) 30–49%]. During the mean follow‐up time of 45 ± 20 months, 17 patients died, two patients withdraw consent, and four patients were lost. Of the remaining patients, four were hospitalized for decompensated heart failure. Two of these patients underwent additional transcatheter edge‐to‐edge mitral valve repair. At follow‐up, New York Heart Association (NYHA) functional class improved from 95% in Class III/IV at baseline to 70% in Class I/II with no patients in NYHA Class IV (P < 0.0001). Mitral regurgitant volume was reduced from 27 mL (IQR 25–42 mL) to 8 mL (IQR 3–17 mL) (P = 0.018) and regurgitant fraction from 42% (IQR 34–54%) to 11% (IQR 8–24%) (P = 0.014). LV end‐diastolic volume index [92 mL/m(2) (IQR 74–107 mL/m(2)) vs. 67 mL/m(2) (IQR 46–101 mL/m(2)), P = 0.065] and end‐systolic volume index [50 mL/m(2) (IQR 44–69 mL/m(2)) vs. 32 mL/m(2) (IQR 20–53 mL/m(2)), P = 0.037] decreased. Total stroke volume remained unchanged [38 mL/m(2) (IQR 33–43 mL/m(2)) vs. 33 mL/m(2) (IQR 26–44 mL/m(2)), P = 0.695], while LV ejection fraction increased [43% (IQR 35–49%) vs. 54% (IQR 46–57%), P = 0.014]. Forward stroke volume, heart rate, and forward cardiac output were not significantly altered. CONCLUSIONS: Among high‐risk patients undergoing transcatheter mitral valve annuloplasty for symptomatic secondary MR, mortality was ~50% at 4 years. In the surviving patients, reduced MR severity was associated with reduced NYHA functional class, reverse LV remodelling, and improved LV function.