Effect of Chronic Obstructive Pulmonary Disease (COPD) on Biventricular Mechanics in Patients Without Severe Airflow...

Background: Over the last 15 years, few echocardiographic studies have examined the biventricular mechanics by speckle tracking echocardiography (STE) in patients affected by chronic obstructive pulmonary disease (COPD) without advanced lung disease. We aimed to summarize the main findings of these studies and quantify the overall effect of COPD on biventricular mechanics in patients without severe airflow obstruction. Methods: Eligible studies assessing cardiac function by conventional transthoracic echocardiography (TTE), implemented with a STE analysis of left ventricular (LV)-global longitudinal strain (GLS) and/or right ventricular (RV)-GLS in COPD patients without severe airflow obstruction vs. healthy controls, were selected from the PubMed, Embase and Scopus databases. The primary endpoint was to quantify the effect of COPD on LV-GLS and RV-GLS in individuals without advanced lung disease. Continuous data [LV-GLS, RV-GLS, left ventricular ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE)] were pooled as the standardized mean difference (SMD) comparing COPD cohorts with healthy controls. Results: Ten studies were included, totaling 682 COPD patients and 316 healthy controls. Overall, COPD showed a large effect on LV-GLS (SMD -1.296; 95%CI -2.010, -0.582, p < 0.001) and RV-GLS (SMD -1.474; 95% CI -2.142, -0.805, p < 0.001), a medium-to-large effect on TAPSE (SMD -0.783, 95% CI -0.949, -0.618, p < 0.001) and a small effect on LVEF (SMD -0.366, 95% CI -0.659, -0.074, p = 0.014). The I² statistic value for the LV-GLS (91.1%), RV-GLS (88.2%) and LVEF (76.7%) studies suggested a high between-study heterogeneity, while that for the TAPSE (38.1%) studies was compatible with a low-to-moderate between-study heterogeneity. Egger's test yielded a p-value of 0.16, 0.48, 0.58 and 0.50 for LV-GLS, RV-GLS, LVEF and TAPSE studies, respectively, indicating an absence of publication bias. Meta-regression analyses excluded that the effect of COPD on biventricular mechanics might be influenced by potential confounders (all p > 0.05). Sensitivity analysis confirmed the robustness of the LV-GLS, RV-GLS and TAPSE studies' results. Conclusions: COPD appears to be independently associated with a mild attenuation of biventricular mechanics in patients with moderate airflow limitations, despite a preserved LVEF and TAPSE on conventional TTE. STE analysis may allow clinicians to identify COPD patients with subclinical myocardial dysfunction and an increased risk of heart failure and cardiovascular complications early.