Severe Mitral Regurgitation and the Use of Transcatheter Mitral Valve Repair Surgical treatment is recommended in cases of severe primary chronic MR resulting in HFrEF (36). The treat- ment for severe chronic functional MR is somewhat controversial; initial steps should incorporate optimiza- tion of GDMT and participation in team management de- cisions before the use of percutaneous transcatheter repair. In 2018, 2 large randomized clinical trials of percuta- neous mitral valve repair were published. The MITRA-FR (Percutaneous Repair with the MitraClip Device for Se- vere Functional/Secondary MR) and COAPT (CV Out- comes Assessment of the MitraClip Percutaneous Therapy for HF Patients with Functional MR) trials reported divergent results. Whereas no bene t from percutaneous clipping of the mitral valve was observed in MITRA-FR, the COAPT study investigators reported that, in a popu- lation with maximally-tolerated GDMT and device ther- apy, there was a reduction in HF hospitalization and mortality in symptomatic HF patients with grade 3 to 4 MR (37,38). Substantial differences exist between MITRA-FR and COAPT, but a primary difference relates to the require- ment in COAPT for optimized GDMT before the use of percutaneous mitral valve edge-to-edge reapposition; in COAPT, 90% of study participants received a beta- blocker, 70% received an ARNI/ACEI/ARB, and 50% received an aldosterone antagonist before the procedure. Optimal GDMT leads to reversal of cardiac remodeling, reduction of LV volumes (7), and a concomitant reduction in functional MR (39); thus, although percutaneous mitral valve repair is of bene t in patients with optimized GDMT and persistent symptoms with severe MR, it is essential that GDMT is optimized before referral for the procedure to ensure the greatest likelihood that patients will receive the combined bene ts of optimal GDMT together with edge-to-edge repair. 5.1.8. 