Patterns of NT-proBNP in Systemic Lupus Erythematosus

OBJECTIVE: We evaluated patterns of N-terminal prohormone of n-terminal brain natriuretic peptide (NT-proBNP, a biomarker of cardiac disease) in SLE, and associations with demographic and clinical characteristics. METHODS: We analyzed data from the McGill SLE Research Cohort, including yearly serum NTproBNP. We assessed prevalence of baseline elevated NT-proBNP (≥133 ng/L) , and associations with baseline variables: age, sex, race/ethnicity, age at SLE diagnosis, SLE duration, smoking, and SLE International Collaborating Clinics Damage Index. Patients were classified into four NT-proBNP patterns: abnormal at baseline and remaining abnormal; abnormal and normalizing; normal and becoming abnormal; normal and remaining normal. We compared baseline characteristics across patterns using multivariate logistic regressions. RESULTS: We studied 294 patients with ≥2 measurements. At baseline, 101 (34.4%) had elevated NT-proBNP. Higher levels were associated with older age at SLE diagnosis, longer SLE duration, cardiovascular damage, pulmonary hypertension, and renal damage. Of 101 individuals with abnormal baseline NT-proBNP, 79 (78.2%) remained abnormal. Of the 193 with normal baseline levels, 30 (15.5%) became abnormal. No patient with a baseline level ≥350 normalized to <133. High-risk patterns (abnormal-remaining-abnormal and normal-becoming-abnormal) were more likely to have cardiovascular damage (OR 3.90, 95% CI 1.49-12.5, renal damage (OR 2.87, 95% CI 1.61-5.51), and pulmonary hypertension (OR 32.0, 95% CI 4.59-651.1). CONCLUSION: Over one-third of SLE patients had abnormal baseline NT-proBNP; most (78%) remained abnormal. Over 15% of those with an initially normal value became abnormal. Higher levels were associated with age, SLE duration, and organ damage. Levels ≥350 ng/L did not normalize over our evaluation.