Assessment of Cardiac Dysfunction in Patients With Chronic Obstructive Pulmonary Disease (COPD): A Cross-Sectional Study

Abstract

Background: Cardiovascular diseases (CVDs) are frequent in patients having chronic obstructive pulmonary disease (COPD). Despite that, comorbid CVDs receive less guideline-recommended screening in this population compared to others. We aimed to evaluate the cardiac function using echocardiography and to assess spirometry, arterial blood gas (ABG) as well as brain natriuretic peptide (BNP) as prognostic indicators of cardiovascular dysfunction in COPD patients. Methods: One hundred moderate to very severe COPD patients according to GOLD guidelines with no history of cardiac diseases were recruited from two hospitals in Saudi Arabia and evaluated using electrocardiography (ECG), chest X-ray, BNP, pulmonary functions, ABG analysis, and transthoracic echocardiography. Multiple linear regression analysis was used to determine the predictors of right ventricular (RV) and left ventricular (LV) dysfunction. Results: Pulmonary hypertension (PH) was detected in 28% of the patients, while 25% had abnormal tricuspid annular plane systolic excursion (TAPSE). Low left ventricular ejection fraction (LVEF) and abnormal LV strain were present in 20%, abnormal right ventricular strain was present in 17%, and abnormal fractional area change (FAC) was detected in 9% of patients. Multiple linear regression analysis was used to explore possible determinants of cardiac function. Age, gender, and the presence of diabetes and hyperlipidemia were significant predictors of cardiac dysfunction in COPD patients. Forced vital capacity (FVC) was an independent predictor of LVEF (odds ratio, OR: 0.424, confidence interval, 95 CI%: 0.025-0.505, p<0.031) and FAC (OR: 0.496, 95 CI%: 0.008-655). Hypoxemia and hypercapnia significantly predict both RV and LV dysfunctions. BNP was an independent predictor of FAC (OR: 0.307, 95 CI%: -0.021, p<0.001). Conclusion: Cardiac abnormalities are common in moderate to very severe COPD patients. Echocardiography could be considered for the assessment of these patients even in the absence of a history of cardiac disease. Pulmonary functions, ABG, and BNP may offer additional predictive information on cardiac functions in COPD patients.