Prognostic value of left ventricular global longitudinal strain in transcatheter edge-to-edge repair for chronic primary mitral regurgitation

Aims Left ventricular global longitudinal strain (LVGLS) is a known outcome predictor in transcatheter edge-to-edge repair (TEER) for functional mitral regurgitation (MR). We aimed to assess its prognostic yield in the setting of TEER for chronic primary MR. Methods and results We conducted a single-centre, retrospective analysis of 323 consecutive patients undergoing isolated, first-time procedures. Stratified by baseline LVGLS quartiles (<=-19%, -18.9% to -16%, -15.9% to -12%, >-12%), the cohort was evaluated for the primary composite outcome of all-cause mortality or heart failure hospitalizations, as well as secondary endpoints consisting of mitral reinterventions and the persistence of significant residual MR and/or functional disability-all along the first year after intervention. Subjects with worse (i.e. less negative) LVGLS exhibited higher comorbidity, more advanced HF, and elevated procedural risk. Post-TEER, those belonging to the worst LVGLS quartile group sustained increased mortality (16.9% vs. 6.3%, Log-Rank P = 0.005, HR 1.75, 95% CI 1.08-4.74, P = 0.041) and, when affected by LV dysfunction/dilatation, more primary outcome events (21.1% vs. 11.5%, Log-Rank P = 0.037, HR 1.68, 95% CI 1.02-5.46, P = 0.047). No association was demonstrated between baseline LVGLS and other endpoints. Upon exploratory analysis, 1-month post-procedural LVGLS directly correlated with and was worse than its baseline counterpart by 1.6%, and a more impaired 1-month value-but not the presence/extent of deterioration-conferred heightened risk for the primary outcome. Conclusion TEER for chronic primary MR is feasible, safe, and efficacious irrespective of baseline LVGLS. Yet, worse baseline LVGLS forecasts a less favourable post-procedural course, presumably reflecting a higher-risk patient profile.