Characterization and Mortality Risk of Impaired Left Ventricular Filling in Chronic Obstructive Pulmonary Disease

Area of Science:

• Cardiology
• Pulmonology
• Echocardiography

Background:

• Impaired left ventricular (LV) filling in chronic obstructive pulmonary disease (COPD) may stem from heart failure with preserved ejection fraction (HFpEF) or reduced pulmonary venous return due to small LV size.
• Distinguishing between these two patterns is crucial for understanding their impact on mortality.

Purpose of the Study:

• To investigate the association of small LV size and HFpEF with all-cause mortality in COPD patients.
• To identify clinical features that differentiate between small LV and HFpEF in this population.

Main Methods:

• Transthoracic echocardiography (TTE) was used to define small LV (LV end-diastolic diameter below normal) and HFpEF features in 1,752 stable COPD patients from the COSYCONET cohort.
• Key parameters assessed included E/A, E/e', N-terminal pro-brain natriuretic peptide, high-sensitivity troponin I, FEV1, residual volume, and DlCO.
• All-cause mortality was tracked for 4.5 years.

Main Results:

• Small LV was present in 8% of patients, HFpEF features in 16%, and normal TTE in 45%.
• Both small LV and HFpEF were associated with significantly higher all-cause mortality compared to normal TTE (HR 2.75 and 2.16, respectively).
• Small LV independently predicted mortality and was characterized by reduced LV filling (low E/A) but normal LV filling pressures (E/e') and lower biomarker levels.

Conclusions:

• Small LV and HFpEF are distinct echocardiographic patterns of impaired LV filling in COPD.
• Both patterns are independently associated with increased all-cause mortality in COPD patients.
• Clinical features and echocardiographic parameters differentiate small LV from HFpEF, aiding in risk stratification.