Prognostic value of NT-proBNP in patients with primary mitral regurgitation undergoing transcatheter edge-to-edge repair

Abstract

Aims: The prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients undergoing mitral valve transcatheter edge-to-edge repair (M-TEER) for primary mitral regurgitation (PMR) is unclear. This study assessed the association between NT-proBNP and outcomes and explored its additive value to the Mitral Regurgitation International Database (MIDA) score.

Methods and results: PRIME-MR, a retrospective, international, multicentre registry, includes 3083 consecutive PMR patients treated with M-TEER. This analysis focused on 1382 patients (median age 81 years, 47% female, 82% New York Heart Association [NYHA] functional class III/IV, median EuroSCORE II 4.1%) with available NT-proBNP levels and follow-up. The primary endpoint was death or heart failure hospitalization within 3 years. Median NT-proBNP level was 1991 pg/ml (T1: 578, T3: 6285), and 384 patients reached the primary endpoint (Kaplan-Meier estimate: 48.5%). Log-transformed NT-proBNP levels independently predicted the primary endpoint (adjusted hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.07-1.28; p < 0.001) after adjusting for NYHA class, haemoglobin, creatinine, and atrial fibrillation. In 1041 patients with a modified MIDA score (median 9), the score was initially associated with the primary endpoint (HR 1.10, 95% CI 1.04-1.17; p = 0.002), but lost significance when adjusting for NT-proBNP levels, which remained independently predictive (adjusted HR 1.20, 95% CI 1.07-1.34; p = 0.002).

Conclusions: NT-proBNP, but not the MIDA score, was independently associated with death or heart failure hospitalizations within 3 years in M-TEER-treated PMR patients. Incorporating NT-proBNP levels into clinical assessment may improve risk stratification and potentially supports earlier intervention at lower NT-proBNP levels to optimize outcomes.

Keywords: Mitral valve transcatheter edge‐to‐edge repair; NT‐proBNP; PRIME‐MR; Primary mitral regurgitation.

Figure 1

Study flowchart. The PRIME‐MR registry includes a total of 3083 patients. N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) and survival status was available in 1382 patients. Patients were categorized into three groups according to NT‐proBNP tertiles. MR, mitral regurgitation; M‐TEER, mitral valve transcatheter edge‐to‐edge repair.

Figure 2

Kaplan–Meier survival curves for all‐cause mortality or heart failure hospitalization within 3 years stratified by N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) tertiles (T1–T3). Significant differences were observed between T1 versus T2 (p = 0.042), T1 versus T3 (p < 0.001), and T2 versus T3 (p = 0.003).

Figure 3

Kaplan–Meier survival curves for all‐cause mortality (A) and heart failure (HF) hospitalization (B) within 3 years stratified by N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) tertiles (T1–T3). For all‐cause mortality, significant differences were observed between T1 versus T2 (p < 0.001) and T2 versus T3 (p < 0.001), but not for T1 versus T2 (p = 0.120). For HF hospitalizations, a significant difference was observed between T1 versus T3 (p = 0.0046). No significant differences were found between other tertile comparisons: T1 versus T2 (p = 0.19) and T2 versus T3 (p = 0.091).

Figure 4

Unadjusted spline curve depicting the association between pre‐interventional N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) levels and hazard ratio for all‐cause mortality or heart failure hospitalization within 3 years. NT‐proBNP values were logarithmically transformed, with the median set as the reference point (hazard ratio = 1). The risk increases progressively with higher NT‐proBNP levels, as shown by the steep rise in the hazard ratio, particularly at the upper end.