The predictive value of intraprocedural mitral gradient for outcomes after MitraClip and its peri-interventional dynamics

Abstract

Background: The current data on the impact of the increased mitral gradient (MG) on outcomes are ambiguous, and intraprocedural assessment of MG can be challenging. Therefore, we aimed to evaluate (a) peri-interventional dynamics of MG, (b) the impact of intraprocedural MG on clinical outcomes, and (c) predictors for unfavorable MG values after MitraClip. Methods: We prospectively included patients who underwent MitraClip. All patients underwent echocardiography at baseline, intraprocedurally, at discharge, and after 6 months. 12-month survival was documented. Results: One hundred and seventy five patients (age 81.2 ± 8.2 years, 61.2% male) with severe mitral regurgitation (MR) were included. We divided our cohort into two groups according to intraprocedural MG with a threshold of 4.5 mm Hg, determined by a multivariate analysis of predictors for 12-month mortality (<4.5 mm Hg: Group 1, ≥4.5 mm Hg: Group 2). Intraprocedural MG ≥4.5 mm Hg was found to be the strongest independent predictor for 12-month mortality (HR: 2.33, P =.03, OR: 1.70, P =.05), and >3.9 mm Hg was associated with adverse functional outcomes (OR: 1.96, P =.04). The baseline leaflet-to-annulus index >1.1 was found to be the strongest independent predictor (OR: 9.74, P =.001) for unfavorable intraprocedural MG, followed by the number of implanted clips (P =.01), MG at baseline (P =.02), and central clip implantation (P =.05). Conclusion: An intraprocedural MG <3.9 mm Hg appears to be the best strategy for 1-year survival and favorable functional outcomes after edge-to-edge MV repair with MitraClip independently from MR etiology. Peri-interventional echocardiographic and procedural parameters are useful for the adequate assessment of intraprocedural MG.