Quantitative Computed Tomography of Pulmonary Emphysema and Ventricular Function in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Hypertension

Objective: This study strived to evaluate the relationship between degree of pulmonary emphysema and cardiac ventricular function in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension (PH) using electrocardiographic-gated multidetector computed tomography (CT). Materials and Methods: Lung transplantation candidates with the diagnosis of COPD and PH were chosen for the study population, and a total of 15 patients were included. The extent of emphysema is defined as the percentage of voxels below -910 Hounsfield units in the lung windows in whole lung CT without intravenous contrast. Heart function parameters were measured by electrocardiographic-gated CT angiography. Linear regression analysis was conducted to examine the associations between percent emphysema and heart function indicators. Results: Significant correlations were found between percent emphysema and right ventricular (RV) measurements, including RV end-diastolic volume ($R^2$ = 0.340, p = 0.023), RV stroke volume ($R^2$ = 0.406, p = 0.011), and RV cardiac output ($R^2$ = 0.382, p = 0.014); the correlations between percent emphysema and left ventricular function indicators were not observed. Conclusion: The study revealed that percent emphysema is correlated with RV dysfunction among COPD patients with PH. Based on our findings, percent emphysema can be considered for use as an indicator to predict the severity of right ventricular dysfunction among COPD patients.