Non-heart transplant surgical approaches with mitral valve operation and surgical ventricular reconstruction for non-ischaemic dilated cardiomyopathy: a Japanese multicenter study

Objectives: There is uncertainty over the efficacy of additional surgical ventricular reconstruction (SVR) associated with mitral valve operation for non-ischaemic dilated cardiomyopathy (DCM). This study aims to assess mid-term outcomes of these non-heart transplant surgical approaches for DCM. Methods: We reviewed retrospectively 106 patients (median age 64, 44 females) who underwent isolated mitral annular plasty (MAP; n = 34), mitral valve replacement (MVR; n = 29), and SVR associated with MAP (SVR + MAP; n = 43) for DCM, in 11 Japanese hospitals. We analysed mid-term outcomes, specifically freedom from cardiac death and cardiac event. Results: Hospital deaths occurred in 16 patients (15.1%) and cardiac deaths in 36 patients (34.0%) during the study period of 4.4 ± 3.5 years. Freedom from cardiac death at 7 years in patients undergoing MAP, MVR, and SVR + MAP were, respectively, 79.1%, 82.6%, and 29.5% (P < 0.0001). Freedom from cardiac event at 7 years in patients undergoing MAP, MVR, and SVR + MAP were, respectively, 42.8%, 59.9%, 22.6% (P = 0.0004). In the multivariable analyses, preoperative tricuspid regurgitation (TR) grade was the only risk factor for both cardiac death and event, whereas MVR for DCM emerged as a protective factor for cardiac event. Conclusions: This study could not show any benefit of additional SVR, by means of volume reduction, to MAP, because the baseline characteristics were different even after the stratification of DCM grade. MVR can be performed with favorable mid-term outcomes even in patients with advanced DCM, while patients undergoing MAP with/without SVR had more frequent MR recurrence or cardiac events. Interestingly, the right ventricular feature is a predictor of both cardiac death and events, with the TR grade being a predictor of poor mid-term outcomes.