SESSION TYPE: Pulmonary Hypertension I
PRESENTED ON: Sunday, October 21, 2012 at 10:30 AM - 11:45 AM
PURPOSE: To assess if different inflammatory biomarkers could inform the diagnosis and risk stratification in pulmonary arterial hypertension (PAH).
METHODS: We measured interleukin-6 (IL-6), ultra-sensitive C-reactive protein (CRP) and myeloperoxidase (MPO) in 77 PAH patients, 49 patients with connective tissue disease (CTD) without PAH, and 49 healthy controls. Comparisons were adjusted for age and gender. In the PAH group, we also recorded usual determinants of PAH severity and time to death since the date of blood sampling.
RESULTS: Population: PAH (age 51 ± 14, female 82%), CTD (age 46 ± 13, female 86%), controls (age 33 ± 8, female 66%). Baseline PAH features: 50 idiopathic, 27 associated PAH (20 CTD, and 7 congenital heart disease), 88% prevalent cases, NYHA class 2.5 ± 0.7, 6MWD 360 ± 127 meters, pericardial effusion 27%, BNP 167 ± 257 pg/mL, right atrial pressure 10 ± 6 mmHg, mean pulmonary artery (PA) pressure 51 ± 13 mmHg, cardiac index 2.4 ± 0.8. Levels of IL-6 and CRP were lowest in controls and highest in PAH, with CTD in the middle, while MPO levels were only elevated in CTD and APAH. Age older than 59, MPO above 2626 pmol/L and CRP above 13 g/L discriminated CTD-PAH from CTD without PAH. Both IL-6 and CRP were univariate predictors of transplant-free survival, while MPO was not. IL-6 and CRP had significant correlations with the 6MWD and NYHA class, while IL-6 also correlated with right atrial pressure, PA diastolic pressure and BNP. A multivariable forward stepwise regression Cox model identified BNP (HR 1.96, 95% CI 1.42 - 2.71 per 1 SD change) and CRP (HR 1.97, 95% CI 1.03 - 3.64 per 1 SD change) as independent predictors of transplant-free survival. A tree-based analysis showed that the combination of BNP, IL-6 and cardiac index best defined patient subsets with different outcomes.
CONCLUSIONS: IL-6 driven inflammation is associated with more severe disease and decreased survival in PAH.
CLINICAL IMPLICATIONS: IL-6 and CRP may aid in the risk stratification of a prevalent PAH population.
DISCLOSURE: The following authors have nothing to disclose: Gustavo Heresi, Metin Aytekin, Raed Dweik
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