When the heart is burning: amino-terminal pro-brain natriuretic peptide as an early marker of cardiac involvement in active autoimmune rheumatic disease.

Background: We evaluated the influence of inflammation on cardiac endocrine function in autoimmune rheumatic disease (RD) patients with preserved left ventricular systolic function.

Methods: 160 consecutive RD patients (29 males, age 55 ± 14 years, left ventricular ejection fraction, LVEF, 63 ± 5%: inflammatory polyarthritis: 13%, systemic sclerosis: 25%, connective tissue diseases: 39%, systemic vasculitides: 23%) and 120 healthy controls (24 males, 55 ± 10 years) underwent clinical, echocardiographic evaluation and blood sampling for erythrocyte sedimentation rate, C-reactive protein (CRP), fibrinogen and plasma NT-proBNP.

Results: A significant correlation was found between plasma NT-proBNP and inflammatory markers (all p<0.001), with CRP and diastolic dysfunction being the only independent predictors of NT-proBNP level. RD patients with active disease (57%) showed higher values of inflammatory markers and NT-proBNP (all p<0.01). Patients with subclinical cardiac involvement (Stage B by ACC/AHA HF-classification) had higher NT-proBNP (p<0.001) than controls and patients only at risk for HF (Stage A). NT-proBNP showed a significant diagnostic accuracy in discriminating stage B (n=93) versus stage A patients (n=67, AUC=0.755 ± 0.038, p<0.001) and controls (AUC=0.834 ± 0.030, p<0.001).

Conclusion: Higher CRP and the presence of left ventricular diastolic dysfunction were independently associated with higher NT-proBNP. NT-proBNP might be used in RD as a marker of both disease activity and subclinical cardiac involvement.