Preliminary Evaluation of NT-proBNP and cTnI as Predictors of Procedure Safety in Dogs Undergoing Transcatheter Edge-to-Edge Mitral Valve Repair

Myxomatous mitral valve disease (MMVD) in dogs can be treated with transcatheter edge-to-edge mitral valve repair (TEER), an emerging minimally invasive surgical technique. However, reports on prognostic markers for preoperative evaluation remain limited. This study evaluated the association of preoperative N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) levels with procedure safety in dogs undergoing TEER. A retrospective analysis was conducted on 25 dogs diagnosed with stage C (n = 18) or D (n = 7) MMVD that underwent TEER between September 2023 and January 2025. Preoperative NT-proBNP and cTnI values were measured and compared between survivors and non-survivors. Among the survivors, 15 and 4 dogs were stages C and D, respectively. Among the non-survivors, three and three dogs were stages C and D, respectively. Non-survivors had higher median NT-proBNP levels (3557 pmol/L; range: 774-10,000) and cTnI levels (0.39 ng/mL; range: 0.22-0.51) than survivors (NT-proBNP: 1262.6 pmol/L, range: 500-8773; cTnI: 0.1 ng/mL, range: 0.01-3.6). However, the two groups showed no significant differences in NT-proBNP (<i>p</i> = 0.187) or cTnI (<i>p</i> = 0.869). Increased preoperative NT-proBNP and cTnI levels were not strong predictors of procedure safety in dogs with MMVD stages C and D undergoing TEER. Further studies with larger sample sizes and longer follow-up periods are needed to better evaluate the prognostic value of these biomarkers in this population.