Echocardiographic Assessment of Pulmonary Artery Pressure and Its Association with Disease Severity in Chronic Obstructive Pulmonary Disease: A Prospective Observational Study

Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung disease with clinically important cardiovascular comorbidity, significant morbidity and mortality. PH is a complication of COPD and linked to increased symptom burden, decreased exercise capacity, right-ventricular dysfunction and worse outcomes. Right-heart catheterization is an invasive procedure and is not indicated for routine examination and evaluation, so transthoracic echocardiography is a safer, non-invasive method to estimate pulmonary artery systolic pressure (PASP) and estimate the likelihood of PH. The aim of this study was to assess the echocardiographic estimation of PASP and its association with the severity of COPD (spiro) as assessed by spirometry. Material and Methods: This was a prospective observational study carried out in Respiratory Medicine Department, Noida International Institute of Medical Sciences (NIIMS), Noida, Uttar Pradesh, India. Sixty patients with spirometry-diagnosed COPD who met the eligibility criteria were enrolled, with no data missing. Severity of the disease was determined by post-bronchodilator FEV1 percentage predicted. Transthoracic echocardiograms (TTE) were performed in all patients. In this study, echocardiographic PH was defined as an estimated systolic pulmonary artery pressure (sPAP) of ≥30 mmHg. Frequencies and percentages were used for summarising data. Results: Among 60 patients, 25 (41.67%) met the study's echocardiographic threshold for PH. Mild, moderate, and severe pressure elevation was observed in 14 (23.33%), 6 (10.00%), and 5 (8.33%) patients, respectively. The frequency of echocardiographic PH increased across spirometric categories, occurring in 23.08% of patients with mild COPD, 46.67% with moderate COPD, 61.54% with severe COPD, and 66.67% with very severe COPD. Conclusion: Echocardiographic evidence of PH was observed in 41.67% of the study population and showed a descriptive increase with worsening airflow limitation. Transthoracic echocardiography may assist the initial evaluation of appropriately selected patients with COPD; however, definitive haemodynamic diagnosis requires right-heart catheterization.

Keywords: Chronic obstructive pulmonary disease; pulmonary hypertension; pulmonary artery systolic pressure; echocardiography; GOLD classification; right-ventricular dysfunction.