Study Background and Disease Burden
Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome predominantly affecting older adults, characterized by symptoms of heart failure despite normal left ventricular ejection fraction. A hallmark of HFpEF is the exaggerated elevation of pulmonary capillary wedge pressure (PCWP) during exertion compared to healthy age-matched controls. This aberrant hemodynamic response contributes to exercise intolerance—a major limiting symptom affecting quality of life and prognosis in this population. Beyond cardiac abnormalities, HFpEF is increasingly recognized as a multisystem disorder involving systemic and pulmonary vascular dysfunction, alongside impairments in respiratory mechanics.
One underappreciated component in HFpEF pathophysiology concerns alterations in lung mechanics, particularly expiratory flow limitation (EFL) and dynamic hyperinflation (DH). EFL, resulting from obstructed expiratory airflow, can cause progressive increases in end-expiratory lung volume during exercise, known as DH. This phenomenon forces ventilation to occur at higher lung volumes, altering intrathoracic pressures, reducing inspiratory capacity, and potentially impacting cardiac filling pressures and overall cardiopulmonary interaction. However, the extent and clinical implications of DH and EFL in HFpEF remain incompletely understood, limiting therapeutic options targeting these lung mechanics abnormalities.
