N-terminal pro-brain-type natriuretic peptide (NT-pro-BNP) and mortality risk in early inflammatory polyarthritis: Results from the Norfolk Arthritis Registry (NOAR)

Abstract

Background: We measured N-terminal pro-brain natriuretic peptide (NT-pro-BNP), a marker of cardiac dysfunction, in an inception cohort with early inflammatory polyarthritis (IP) and assessed its association with disease phenotype, cardiovascular disease (CVD), all-cause and CVD related mortality. Methods: Subjects with early IP were recruited to the Norfolk Arthritis Register from January 2000 to December 2008 and followed up to death or until March 2010 including any data from the national death register. The associations of baseline NT-pro-BNP with IP related factors and CVD were assessed by linear regression. Cox proportional hazards models examined the independent association of baseline NT-pro-BNP with all-cause and CVD mortality. Results: We studied 960 early IP subjects; 163 (17%) had prior CVD. 373 (39%) patients had a baseline NT-pro-BNP levels ≥100 pg/ml. NT-pro-BNP was associated with age, female gender, HAQ score, CRP, current smoking, history of hypertension, prior CVD and the presence of carotid plaque. 92 (10%) IP subjects died including 31 (3%) from CVD. In an age and gender adjusted analysis, having a raised NT-pro-BNP level (≥100 pg/ml) was associated with both all-cause and CVD mortality (adjusted HR (95% CI) 2.36 (1.42 to 3.94) and 3.40 (1.28 to 9.03), respectively). These findings were robust to adjustment for conventional CVD risk factors and prevalent CVD. Conclusions: In early IP patients, elevated NT-pro-BNP is related to HAQ and CRP and predicts all-cause and CVD mortality independently of conventional CVD risk factors. Further study is required to identify whether NT-pro-BNP may be clinically useful in targeting intensive interventions to IP patients at greatest risk of CVD.