Utility of B-type natriuretic peptides in the assessment of patients with systemic sclerosis-associated pulmonary hypertension in the PHAROS registry

Objective. To assess the utility of B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) in detecting and monitoring pulmonary hypertension (PH) in systemic sclerosis (SSc). Methods. PHAROS is a multicenter prospective cohort of SSc patients at high risk for developing pulmonary arterial hypertension (SSc-AR-PAH) or with a definitive diagnosis of SSc- PH. We evaluated 1) the sensitivity and specificity of BNP≥64 and NT-proBNP ≥ 210 pg/mL for the detection of SSc-PAH and/or SSc-PH in the SSc-ARPAH population; 2) baseline and longitudinal BNP and NT-proBNP levels as predictors of progression to SSc-PAH and/or SSc-PH; 3) baseline BNP≥180, NT-proBNP≥553 pg/mL, and longitudinal changes in BNP and NT-proBNP as predictors of mortality in SSc-PH diagnosed patients. Results. 172 SSc-PH and 157 SSc-ARPAH patients had natriuretic peptide levels available. Median BNP and NTproBNP were significantly higher in the SSc-PH versus SSc-AR-PAH group. The sensitivity and specificity for SSc- PAH detection using baseline BNP≥64 pg/mL was 71% and 59%; and for NTproBNP≥ 210 pg/mL, 73% and 78%. NT-proBNP showed stronger correlations with haemodynamic indicators of right ventricular dysfunction than BNP. Baseline creatinine, RVSP > 40 mmHg, and FVC%:DLCO% ratio ≥1.8 were associated with progression from SSc-ARPAH to SSc-PH but no association with individual or combined baseline BNP and NT-proBNP levels was observed. Baseline and follow-up BNP or NTproBNP levels were not predictive of death, however, a composite BNP/NTproBNP group predicted mortality (HR 3.81 (2.08-6.99), p < .0001). Conclusion. NT-proBNP may be more useful than BNP in the detection and monitoring of PAH in SSc patients, but additional studies are necessary.