Echocardiographic Evaluation of the Relationship between inflammatory factors (IL6, TNFα, hs-CRP) and Secondary Pulmonary Hypertension in patients with COPD: A Cross sectional study

Abstract

Background: Inflammatory mechanism appears to play a major role in the pathogenesis of various types of human pulmonary hypertension such as idiopathic PAH (IPAH) and PAH associated'' with connective tissue disease. Although we know that inflammatory factors such as IL6 and TNFa have an important role in IPAH, there is limited information about the relationship between acute phase reactants and pulmonary hypertension occurring secondary to pulmonary diseases such as chronic obstructive pulmonary diseases (COPD). Methods: This cross-sectional study was carried out on 94 patients who had COPD. Patients with a recent history of systemic steroid and acetylsalicylic acid ( ASA) use, infection, trauma or surgery, gastrointestinal bleeding, coronary artery disease (CAD) and Hypertension were excluded. Body plethysmography and transthoracic echocardiography were done. Blood samples for each patient included were drawn for complete blood count (CBC), IL6, TNFa and highly sensitive C reactive protein (hs-CRP). Results: Twenty patients (28.6%) had pulmonary hypertension. The difference between the mean IL6 and hs-CRP in patients with and without pulmonary hypertension was significant (7pg/ml vs. 4.4pg/ml and 13.04pg/ml vs. 3.31pg/ml) (p= 0.006 and p=0.000). There was a correlation between IL6 and mean pulmonary arterial pressure (r = 0.35, p=0.003). After adjustment for age, sex, serum Hemoglobin, Hematocrit, O2Sat, FEV1, FVC the relationship between the IL6, hs-CRP and the presence of pulmonary hypertension remained significant (p=0.022, p=0.026) . Conclusion: Inflammatory factors such as IL6 and hs-CRP are independent risk factors for pulmonary hypertension in COPD patients.