Abstract Body (Do not enter title and authors here): Background: Transcatheter edge-to-edge mitral valve repair (TEER) is an established procedure in patients with severe mitral regurgitation (MR) and elevated surgical risk on optimal medical therapy. However, there remains considerable mortality in this patient population. Some studies have shown that serum brain natriuretic peptide (BNP) and N-terminal pro b-type natriuretic peptide (NT-proBNP) predict all-cause mortality after TEER, whereas other studies have shown mortality to be independent of these markers. To address this gap in knowledge, we sought to examine the existing literature to determine whether there is an association between pre-procedural serum natriuretic peptides and mortality after TEER.

Hypothesis: Among patients undergoing TEER, elevated pre-procedural BNP and NT-proBNP are associated with increased all-cause mortality.

Methods: Databases including MEDLINE, Embase, and Cochrane Library were searched from inception through September 2023 for studies assessing pre-procedural serum natriuretic peptide levels and mortality among patients undergoing TEER. Pooled hazard ratios (HR) and standardized mean differences (SMD) were calculated using a random-effects model estimated by restricted maximum likelihood with the Hartung-Knapp modification.

Results: A total of 30 studies comprising 10259 patients undergoing TEER met inclusion criteria. 25 studies measured NT-proBNP and 5 studies measured BNP. Elevated pre-procedural NT-proBNP (>5000 or >10000 pg/mL) was associated with increased all-cause mortality in both adjusted (HR = 2.94; 95% CI = 1.75 - 4.95; I2 = 46.8%) and unadjusted (HR = 5.16; 95% CI = 1.85 - 14.40; I2 = 0.0%) analyses (Figures 1 and 2). Pre-procedural BNP and NT-proBNP were also significantly lower among survivors at 12 months compared to non-survivors (SMD = 0.82; 95% CI = 0.37 - 1.27; I2 = 78.3%) (Figure 3). This association was demonstrated in patients with primary or secondary MR.

Conclusions: Pre-procedural BNP and NT-proBNP levels are significant predictors of all-cause mortality in patients undergoing TEER for primary or secondary MR. This supports the inclusion of BNP or NT-proBNP in pre-procedural assessments to help inform patient discussions and guide post-procedural follow-up and monitoring.