Background: N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiopulmonary exercise testing (CPET) are useful for severity assessment in patients with pulmonary hypertension (PH). Correlations between these tests in pre-capillary PH patients is less well studied. Methods: We studied 23 patients with pre-capillary PH: 8 with idiopathic pulmonary arterial hypertension (IPAH), 6 with systemic sclerosis-associated PAH (SSc-PAH), and 9 with chronic thromboembolic pulmonary hypertension (CTEPH). Clinical evaluation, NT-proBNP levels, six-minute walking test (6MWT), spirometry, and CPET were evaluated on the same day. Correlation between NT-proBNP levels and CPET parameters were investigated. Results: In all patients, NT-proBNP levels were significantly correlated with peak oxygen uptake (VO2) ( r = −0.47), peak oxygen pulse ( r = −0.43), peak cardiac output (CO) ( r = −0.57), peak end-tidal partial pressure of carbon dioxide (PETCO2) ( r = −0.74), ventilatory equivalent to carbon dioxide (VE/VCO2) at anaerobic threshold (AT) ( r = 0.73), and VE/VCO2 slope ( r = 0.64). Significant correlations between NT-proBNP levels and peak PETCO2 and VE/VCO2 were found in IPAH and CTEPH subgroups, and a significant correlation between NT-proBNP levels and VO2 at AT was found in the CTEPH subgroup. No significant correlation was found in the SSc-PAH subgroup. Conclusion: NT-proBNP levels were significantly correlated with CPET parameters in patients with IPAH and CTEPH subgroups, but not in SSc-PAH subgroup. A further study with larger population is required to confirm these preliminary findings.
Original research Evaluation of exercise capacity with cardiopulmonary exercise testing and BNP levels in adult patients with single or systemic right ventricles
