Left Atrial Strain Predicts Poor Exercise Capacity in Patients With Indeterminate Diastolic Function

Area of Science:

• Cardiology
• Echocardiography
• Diastolic Function

Background:

• Diastolic dysfunction has limited diagnostic accuracy, with ~20% indeterminate cases per guidelines.
• Left atrial strain shows potential for improved diastolic dysfunction assessment.
• The specific role of left atrial reservoir strain (LARS) requires further investigation.

Purpose of the Study:

• To investigate the impact of LARS on exercise capacity.
• To determine the association between LARS and exercise capacity in patients with indeterminate diastolic function.

Main Methods:

• 118 patients with indeterminate diastolic function underwent cardiopulmonary exercise testing and stress echocardiography.
• Exclusion criteria included atrial fibrillation and significant valvular heart disease.
• Poor exercise tolerance defined as peak oxygen consumption (pVO₂) <14 mL/kg/min.

Main Results:

• LARS was independently associated with pVO₂ (β=0.12, p<0.001).
• LARS was a strong predictor of impaired pVO₂ (AUC: 0.871), with an optimal cut-off of 21%.
• Patients with LARS ≤21% had significantly reduced exercise capacity (OR, 12.77; p<0.001).

Conclusions:

• LARS is significantly associated with exercise capacity in indeterminate diastolic dysfunction.
• Impaired LARS predicts exercise intolerance, enhancing diastolic function assessment.
• Measuring LARS can improve individualized management of diastolic dysfunction.