Comparing cardiac function and structure and their relationship with exercise capacity between patients with stable COPD and recent acute exacerbation: a cross-sectional study

OBJECTIVE: Patients with COPD are prone to cardiac remodeling; however, little is known about cardiac function in patients recovering from an acute exacerbation of COPD (AECOPD) and its association with exercise capacity. The aim of this study was to evaluate the cardiac function and structure and to compare their relationship with exercise capacity in patients with a recent AECOPD and patients with clinically stable COPD. METHODS: This was a cross-sectional study including 40 COPD patients equally divided into two groups: recent AECOPD group (AEG) and clinically stable COPD group (STG). Echocardiography was performed to assess cardiac function and chamber structure. The six-minute walk distance (6MWD) and the Duke Activity Status Index (estimated Vo(2)) were used in order to assess exercise capacity. RESULTS: No significant differences in cardiac function and structure were found between the groups. The 6MWD was associated with early/late diastolic mitral filling velocity ratio (r = 0.50; p < 0.01), left ventricular posterior wall thickness (r = −0.33; p = 0.03), and right atrium volume index (r = −0.34; p = 0.04), whereas Vo(2) was associated with right atrium volume index (r = −0.40; p = 0.02). CONCLUSIONS: Regardless of the clinical condition (recent AECOPD vs. stable COPD), the cardiac function and structure were similar between the groups, and exercise capacity (determined by the 6MWD and Vo(2)) was associated with cardiac features.