PURPOSE:CRP and NT-proBNP are predictors of cardiovascular mortality. The purpose of this study was to evaluate the relation between these 2 markers. Patients with an impaired lung function are at increased risk of cardiovascular disease. CRP levels have been associated both with cardiovascular mortality and the degree of pulmonary inflammation in COPD. Another aim was to investigate the impact of lung disease on the relation between CRP and NT-proBNP.
METHODS:CRP and NT-proBNP were measured in 697 outpatients (57.5±16.4 years) with dyspnea. The patients were stratified into 3 groups according to the CRP values [stratum I: CRP ≤; 5 mg/l (n = 510), stratum II: CRP >5–10 mg/l (n = 97), stratum III: CRP > 10 mg/l (n = 90)] and classified into 2 categories based on the presence (n = 176) and absence (n = 521) of heart disease.
RESULTS:In patients without heart disease, NT-proBNP significantly (p<0.001) increased from CRP-stratum I (adjusted mean: 48.1 pg/ml, 95%-CI: 44.1–52.4 pg/ml) to CRP-stratum II (65.6 pg/ml; 95%-CI: 58.5–73.6 pg/ml) and to CRP-stratum III (89.4 pg/ml; 95%-CI: 71.5–112.0 pg/ml) after adjusting for age, sex, body mass index, and arterial hypertension. Likewise, the CRP-strata were predictive (p<0.001) of NT-proBNP in patients with heart disease after adjusting for cardiac disorders with NT-proBNP increasing from 261.0 pg/ml (95%-CI: 204.3–333.4 pg/ml) in CRP-stratum I to 453.7 pg/ml (95%-CI: 369.4–557.2 pg/ml) in CRP-stratum II and to 788.5 pg/ml (95%-CI: 540-1150 pg/ml) in CRP-stratum III. The presence of lung disease and the severity of airway obstruction had no effect on the relation between CRP and NT-proBNP.
CONCLUSION:CRP is a predictor of NT-proBNP in patients with and without heart disease. This relation was found at NT-proBNP levels well below currently used threshold values to rule out heart disease.
CLINICAL IMPLICATIONS:An ongoing systemic inflammation puts an excess burden on the heart. This inflammation-related cardiac strain is not affected by the pulmonary status and might account for the increased risk of cardiovascular events in patients with elevated CRP.
DISCLOSURE:Siegfried Wieshammer, No Financial Disclosure Information; No Product/Research Disclosure Information