Treating symptoms and reversing remodelling: clinical and echocardiographic 1-year outcomes with percutaneous mitral annuloplasty for mild to moderate secondary mitral regurgitation

Aims: To determine the effects of percutaneous mitral annuloplasty on symptoms, walk distance and left ventricular (LV) structure and function in patients with mild or moderate secondary mitral regurgitation (SMR).

Methods and results: This was a pooled analysis of patients (n = 68) who, despite guideline-directed medical therapy had symptomatic heart failure (HF) with mild (n = 25) or moderate (n = 43) SMR treated with percutaneous mitral annuloplasty as part of the TITAN, TITAN II, or REDUCE-FMR trials. Primary outcomes were changes in symptoms, 6-min walk distance, and quality of life assessed by the Kansas City Cardiomyopathy Questionnaire (KCCQ) after 1 year. Secondary analyses included changes in LV structure and function. At 1 year, New York Heart Association class status was maintained (48%) or improved (46%) in most patients, mean KCCQ scores increased from baseline by 10 units [95% confidence interval (CI) 3 to17; P < 0.01] and mean 6-min walk test distance increased by 34 m (95% CI 12 to 57; P < 0.01). SMR grade improved in 25% of patients and was maintained in 58% of patients with changes in mean regurgitant volume of -7 mL (95% CI -11 to -3; P < 0.001), vena contracta -0.11 cm (95% CI -0.20 to -0.02; P < 0.05), and effective regurgitant orifice area -0.03 cm² (95% CI -0.06 to -0.01; P < 0.05). There were non-significant improvements in LV ejection fraction and volumes. Survival over 1 year was 89% with no difference between mild (96%) and moderate (86%) SMR (log-rank P = 0.22). Progression-free survival was 70% (82% in mild vs. 63% in moderate SMR; P = 0.16). Freedom from HF hospitalization was 73% (87% in mild SMR vs. 66% in moderate SMR; P = 0.07).

Conclusion: Among patients with symptomatic HF and mild or moderate SMR on guideline-directed medical therapy, percutaneous mitral annuloplasty was associated with improvements in symptoms, SMR, a stabilization of LV structure and function, and high survival rates.