Continuous Direct Left Atrial Pressure: Intraprocedural Measurement Predicts Clinical Response Following MitraClip Therapy

Objectives: The aim of this study was to assess the additional utility of measuring left atrial (LA) pressure as a complement to transesophageal echocardiography (TEE) and Doppler imaging. Background: The efficacy of the MitraClip (MC) is assessed intraoperatively by TEE. However, TEE measures are operator dependent and can be influenced by left ventricular (LV) function and changes in LA compliance. Methods: Fifty patients undergoing MC therapy with continuous left-sided heart pressure measurements were analyzed. LA V-wave pressure (LAvP), LA mean pressure (LAmP), LV systolic pressure, and LV end-diastolic pressure were measured continuously. LA pressures were indexed to LV pressures to account for changes in afterload during the procedure. Results: Most patients (70%) had degenerative mitral regurgitation (MR). TEE MR grade decreased from 3+ to 0+. LAvP (p < 0.001), LAmP (p = 0.007), LV end-diastolic pressure (p = 0.001), LAvP index (p < 0.001), and LAmP index (p = 0.001) decreased significantly, and LV systolic pressure(p = 0.009) significantly increased after MC therapy. In multivariate Cox regression analysis, intraprocedural increase of LAmP index, but not post-MC ≥2+ residual MR, was significantly associated with rehospitalization due to heart failure (hazard ratio: 3.377; 95% CI: 3.180 to 3.585; p = 0.007) and with New York Heart Association functional class III to IV (hazard ratio: 1.497; 95% CI: 1.006 to 2.102; p = 0.005) in the follow-up period. Conclusions: This study demonstrates the value of real-time monitoring of LA pressure during MC therapy to predict clinical outcomes. An increase in LAmP was a predictive of worse clinical outcomes at short-term follow-up, independent from echocardiographic findings.