Impact of Left Atrial Pressure on Outcomes after Mitral Transcatheter Edge-to-Edge Repair

BACKGROUND: Increased left atrial pressure (LAP) has been associated with adverse outcomes after mitral transcatheter edge-to-edge repair (M-TEER). We sought to evaluate outcomes based on differences in postprocedural LAP measured after the final clip deployment. METHODS: We included consecutive patients who underwent M-TEER at our institution between 2014 and 2022 with LAP monitoring. Patients were stratified into 3 groups according to tertiles of post-TEER mean LAP. Outcomes were assessed using Kaplan-Meier analysis and Cox proportional hazards models. RESULTS: We included 273 patients (mean age, 76.8±10.8 years; 42.5% women; 78.4% White). The mean post-TEER LAP was 8.7±1.7 mm Hg in tertile 1 (n=85), 14.4±1.6 mm Hg in tertile 2 (n=95), and 21.9±3.8 mm Hg in tertile 3 (n=93). In comparison with tertile 1, both tertiles 2 and 3 were associated with increased risk of all-cause mortality or heart failure hospitalization at 2 years (adjusted hazard ratio [adjHR], 2.27 [95% CI, 1.25-4.12] and adjHR, 3.00 [95% CI, 1.59-5.64], respectively). Among patients with primary mitral regurgitation, higher LAP was associated with increased risk of 2-year all-cause mortality or heart failure hospitalization (tertile 2 versus 1: adjHR, 3.00 [95% CI, 1.37-6.56]; tertile 3 versus 1: adjHR, 5.52 [95% CI, 2.04-14.95]). However, in patients with secondary mitral regurgitation, neither being in tertile 2 (adjHR, 1.53 [95% CI, 0.55-4.24]) nor tertile 3 (adjHR, 2.18 [95% CI, 0.82-5.77]) were associated with the composite outcome compared with tertile 1. Any degree of LAP reduction following M-TEER was associated with lower mortality or heart failure hospitalization compared with no LAP reduction (adjHR, 0.59 [95% CI, 0.39-0.88]). CONCLUSIONS: Elevated LAP after M-TEER was associated with increased 2-year risk of mortality or heart failure hospitalization. Exploration of reasons for elevated LAP after M-TEER and ways to lower it warrant further investigation.