Impaired Left Atrial Reserve Function in Heart Failure With Preserved Ejection Fraction

Area of Science:

• Cardiology
• Echocardiography
• Heart Failure Research

Background:

• Left atrial (LA) dysfunction is prevalent in heart failure with preserved ejection fraction (HFpEF).
• Limited data exist on the pathophysiologic effects of impaired LA functional reserve.

Purpose of the Study:

• To investigate the association between abnormal LA dynamics during exercise and cardiovascular reserve, exercise capacity, and clinical outcomes in HFpEF patients.

Main Methods:

• Exercise stress echocardiography with expired gas analysis was performed on 231 HFpEF patients and 219 controls.
• LA function was assessed at rest and during exercise using speckle-tracking echocardiography.

Main Results:

• HFpEF patients showed reduced increases in LA reservoir and booster pump strain during exercise compared to controls.
• Impaired exercise LA reservoir strain correlated with diminished biventricular systolic reserve, reduced cardiac output augmentation, and lower peak oxygen consumption.
• Lower exercise LA reservoir strain was associated with a 2.7-fold increased risk of HF events.
• Guideline-directed medical therapy and atrial fibrillation ablation improved LA reservoir and booster pump strain.

Conclusions:

• Impaired LA reservoir function during exercise in HFpEF is linked to biventricular reserve limitations and exercise intolerance.
• This impairment is associated with an increased risk of HF events.