Functional capacity and inflammatory biomarkers as predictors for right atrial volume index in COPD patients

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and right-heart complications. So, this study aimed to evaluate the role of right atrial volume index (RAVI), inflammatory biomarkers and functional capacity in predicting poor outcomes for patients with COPD, classified by COPD assessment test (CAT) questionnaire, as early predictors of right heart diseases.

151 patients with COPD with ejection fraction (LVEF) > 55% were enrolled and classified according to CAT questionnaire into CAT ≥ 10 (group I) and CAT < 10 (group II). RAVI was calculated using Echocardiography. Assessment of RV systolic function was done by Doppler imaging. Functional capacity parameters were assessed by modified medical research council dyspnea scale (mMRC). IL-1β, adiponectin, hs-CRP and neopterin were evaluated by ELSA kits.

Group I (CAT ≥ 10) had higher RAVI (73.92 ± 21.20 ml/m² vs 22.73 ± 6.24 ml/m², p < 0.001), lower S`tri (0.05 ± 0.01 vs 0.13 ± 0.03 m/s, p < 0.001), lower tricuspid annular plane systolic excursion (TAPSE) (1.20 ± 0.17 cm vs 2.17 ± 0.48 cm, p < 0.001), higher RVSP (54.88 ± 7.97 vs 26.79 ± 9.84 mmHg, p < 0.001) compared with group II (CAT < 10). RAVI was good predictor of CAT (r = 0.954, p < 0.001) and strongly correlated with tricuspid S`tri, RVSP, tricuspid E/e' and Mitral E/e' (r = -0.737, r = 0.753, r = 0.817 and r = 0.515, respectively, p < 0.001). RAVI was correlated with TAPSE (r = -0.673, p < 0.001) and with tricuspid E/A ratio & LVEF (r = 0.628, r = -0.407, respectively, p < 0.001). Hs-CRP: 2.50 ± 1.43 vs 2.03 ± 1.19, IL-1β: 37.96 ± 14.35 vs 27.57 ± 8.06, neopterin: 91.37 ± 17.30 vs 76.90 ± 16.75, p < 0.05) were significantly higher besides lower adiponectin levels (3.19 ± 1.98 vs 5.32 ± 1.33 p < 0.05) in group I as compared to group II.

Functional capacity might be useful predictor for right heart diseases in COPD patients. Inflammatory biomarkers, low adiponectin and high Hs-CRP, IL-1β and neopterin levels, might not only be useful to monitor treatment response but may also help to discriminate patients with a worsen prognosis.