Although COAPT was successful, MITRA.fr was not. The prevailing theories as to the difference in the trials is the amount of left ventricular dysfunction in enrolled patients. This is a pooled analysis of patients with functional MR and severe LV enlargement (LV end-diastolic diameter > 65 mm) who were treated with GDMT and the Carillon device vs GDMT alone – i.e., MITRA.fr patients. Key outcomes of this analysis were changes over 1 year of follow-up in mitral valve and LV echocardiographic parameters, functional outcome, quality of life, mortality, and heart failure hospitalization (HFH).

• A total of 95 patients (67 Carillon group; 28 GDMT group) with severe LV enlargement were included.
• In the Carillon group, all mitral valve and LV morphology parameters were significantly improved at 1 year.
  • Regurgitant volume decreased by 12 ml (p<0.001)
  • MR grade decreased by 0.6 units (p<0.001)
  • LV end-diastolic volume decreased by 25 cc (p=0.005)
  • LV end-systolic volume decreased by 21 cc (p=0.01)
• Significant functional improvement differences were also noted between the Carillon group vs. GDMT group:
  • Improvement of KCCQ score (15±4 vs 6±6; p=0.03)
  • Incidence of HFH was 29.9% vs. 50.0% and the cumulative rate of HFH was 0.43 vs. 0.75 (p<0.001)

In conclusion, “In patients with functional MR and severe LV enlargement, the Carillon device improved mitral valve function, LV morphology, and functional outcome compared to patients receiving GDMT only. Preoperative LV dimension should not be a limiting factor when evaluating patient eligibility or anticipated response to therapy with the Carillon device.”