Contractile Reserve in Heart Failure with Preserved Ejection Fraction

Area of Science:

• Cardiology
• Diagnostic Imaging
• Heart Failure Research

Background:

• Diastolic stress echocardiography (SE) aids in diagnosing heart failure with preserved left ventricular ejection fraction (HFpEF) when initial tests are inconclusive.
• New echocardiographic parameters require evaluation for their diagnostic utility in suspected HFpEF cases presenting with dyspnea.

Purpose of the Study:

• To evaluate novel echocardiographic parameters during diastolic SE for diagnosing HFpEF.
• To assess the diagnostic value of contractile reserve (LVCR) using left ventricular ejection fraction (LVEF), stress-to-rest ratio of force, and global longitudinal strain (GLS).

Main Methods:

• Sixty-two patients with exertional dyspnea and inconclusive rest echocardiography underwent exercise SE.
• Left ventricular contractile reserve (LVCR) was assessed by changes in LVEF, stress-to-rest ratio of force, and mechanical reserve (change in GLS from rest to peak stress).

Main Results:

• SE diagnosed HFpEF in 26 patients. Group A (HFpEF) showed a significant increase in E/e' ratio at peak stress compared to Group B.
• Left ventricular global longitudinal strain (GLS) was significantly reduced at rest and stress in Group A versus Group B (p=0.01 at rest, p=0.04 at stress).
• GLS did not increase significantly at peak stress in Group A, but did increase in Group B (p=0.04), indicating impaired mechanical reserve in HFpEF.

Conclusions:

• Patients with HFpEF exhibit impaired left ventricular contractile reserve (LVCR) when assessed by global longitudinal strain (GLS).
• Assessment of mechanical reserve via GLS during stress echocardiography provides additional diagnostic information for HFpEF.