Although any degree of secondary mitral regurgitation (SMR) is known to further complicate heart failure symptoms and mortality, a treatment paradigm for patients with mild and moderate SMR is lacking. The recent publication on Carillon in the European Journal of Heart Failure – Treating symptoms and reversing remodelling: clinical and echocardiographic 1-year outcomes with percutaneous mitral annuloplasty for mild to moderate secondary mitral regurgitation – was particularly enlightening.

The purpose of the authors’ investigation was to determine the effects of percutaneous mitral annuloplasty on symptoms, 6-minute walk distance, and left ventricular (LV) structure and function in patients with mild or moderate SMR in heart failure with reduced ejection fraction. They examined a total of 68 patients from all Carillon trials who had mild and moderate SMR in a retrospective study of one-year outcomes. The findings were very encouraging:

• Mean 6-minute walk test distance increased by 34 m (95% CI 12 to 57; P < 0.01)
• Mean KCCQ scores increased from baseline by 10 units [95% confidence interval (CI) 3 to 17; 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)
• New York Heart Association class status was maintained (48%) or improved (46%) in the vast majority of patients
• Survival over one year was 89% and freedom from HF hospitalization was 73%

The authors conclude: “Among patients with symptomatic HF and mild or moderate SMR on guideline-directed medical therapy, percutaneous mitral annuloplasty [i.e., the Carillon therapy] was associated with improvements in symptoms, SMR, a stabilization of LV structure and function, and high survival rates.”