Efficacy of Native T1 Mapping for Patients With Non-Ischemic Cardiomyopathy and Ventricular Functional Mitral Regurgitation Undergoing Transcatheter Edge-to-Edge Repair

Background: We investigated the efficacy of left ventricular (LV) myocardial damage by native T1 mapping obtained with cardiac magnetic resonance (CMR) for patients undergoing transcatheter edge -to -edge repair (TEER). Methods and Results: We studied 40 symptomatic non-ischemic heart failure (HF) patients and ventricular functional mitral regurgitation (VFMR) undergoing TEER. LV myocardial damage was defined as the native T1 Z -score, which was converted from native T1 values obtained with CMR. The primary endpoint was defined as HF rehospitalization or cardiovascular death over 12 months after TEER. Multivariable Cox proportional hazards analysis showed that the native T1 Z -score was the only independent parameter associated with cardiovascular events (hazard ratio 3.40; 95% confidential interval 1.51-7.67), and that patients with native T1 Z -scores <2.41 experienced significantly fewer cardiovascular events than those with native T1 Z -scores >= 2.41 (P=0.001). Moreover, the combination of a native T1 Z -score <2.41 and more severe VFMR (effective regurgitant orifice area [EROA] >= 0.30 cm(2)) was associated with fewer cardiovascular events than a native T1 Z -score >= 2.41 and less severe VFMR (EROA <0.30 cm(2); P=0.002). Conclusions: Assessment of baseline LV myocardial damage based on native T1 Z -scores obtained with CMR without gadoliniumbased contrast media is a valuable additional parameter for better management of HF patients and VFMR following TEER.