P2796Percutaneous treatment of severe mitral regurgitation with mitraclip device: potential role of NT-proBNP in prognosis assessment

Abstract

Introduction: The implantation of mitraclip (MC) device for the treatment of patients with severe mitral regurgitation (MR) is increasing. Although the procedure is associated with high immediate success rates, tools for prognosis stratification could improve the clinical evaluation of patients with MC. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a widely used cardiac biomarker in heart failure (HF). Purpose: To evaluate the usefulness of NT-proBNP in prognostic stratification. Methods: Retrospective study of 50 patients with severe MR and treated with MC. The preprocedural NT-proBNP level cutoff point of ≥5487 pg/ml was identified by ROC analysis for the prediction of endpoints (emergency department visit or rehospitalization due to HF and death). Accordingly, patients were classified in low or high NT-proBNP group. To clarify the response of NT-proBNP after MC, we analyzed the decrease percentage of NT-proBNP levels at 6 months followup. The patients whose NT-proBNP level decreased by ≥30% were defined as responders. Four groups were created: (G1) low NT-proBNP/responders, (G2) low NT-proBNP/non responders, (G3) high NT-proBNP/responders and (G4) high NT-proBNP/non responders. Results: MC was successfully implanted in 98% of the patients (acute MR ≤2+). Most of the patients presented preprocedural NT-proBNP <5487 pg /ml (68%). The mean age (72 years ± 9.7), sex (male 66%), functional mechanism (82%) and severity of MR (grades III and IV, 20% and 80%) were similar regardless the preprocedural NT-proBNP levels. Comorbidities were more severe in patients with high NT-proBNP levels; highest Euroscore II (12.06 vs 5.71; p=0.01), renal dysfunction (serum creatinine 1.95 vs 1.31 mg/dl, p=0.003), severe depression of left ventricular function (ejection fraction <30%: 14% vs 12%; p=0.03) and right ventricular dysfunction (TAPSE 15 vs 21 mm, p=0.01). In the groups with high NTproBNP, G4 patients presented higher prevalence of advanced HF compared to the G3 patients (NYHA III / IV 43% / 13% vs 19% / 6%, p=0.01) and required more clips during the procedure (mean number of implanted MC 2 vs 1.5; p=0.03). In general, the groups with high NT-proBNP levels presented higher prevalence of adverse events than the groups with low NT-proBNP levels (26% vs 16%, p=0.01). Mortality at 30 days was 6% and between 31- 180 days by 10%, mostly in G4 group. The Kaplan Meier curves showed benefit at 6 months in the groups with low NT-proBNP for rehospitalization (Fig. 1, p=0.04) and for the composite of endpoints (Fig. 2, p=0.03). Conclusions: The preprocedural NT-proBNP levels and its response after MC implantation allowed the identification of patients with a greater risk of endpoints at 6 months. The heterogeneity of the patients with MR associated with multiple comorbidities suggest the need for additional studies to identify the ideal NT-proBNP cut-off point levels. (Figure Presented) .