Significance of plasma N-terminal pro-brain natriuretic peptide in patients with systemic sclerosis-related pulmonary arterial hypertension

OBJECTIVES: A single centre pilot study to investigate the role of the plasma N-terminal pro-brain natriuretic peptide (N-T proBNP) assay to risk stratify patients with suspected pulmonary arterial hypertension (PAH) from a background SSc population. METHODS: Out of 49 SSc patients, 23 had and 26 did not have PAH. Right ventricular haemodynamic variables, six-minute walk test and plasma N-T proBNP levels were recorded from patients catheterised for suspected PAH (23 with PAH and 11/26 without PAH). RESULTS: Mean value of N-T proBNP for SSc patients with PAH was 3365 (standard error 1095) pg/ml compared to 347 (174) pg/ml for patients without PAH. There was a statistically significant correlation (P < 0.05) between N-T proBNP values and (i) mean pulmonary artery pressure (r = 0.53), (ii) right ventricular end diastolic pressure (r = 0.59) and (iii) pulmonary vascular resistance (r = 0.49). Receiver operator characteristic curve analysis showed that a cut-off value of 395.34 pg/ml had a sensitivity of 0.69 and specificity of 1.0. CONCLUSIONS: N-T proBNP estimation in systemic sclerosis-related pulmonary hypertension is a potentially useful diagnostic tool with a high specificity and negative predictive value. This test has the potential to have an important role in risk stratification and monitoring of therapy in the future.