Vasodilator Strain Stress Echocardiography in Suspected Coronary Microvascular Angina

Area of Science:

• Cardiology
• Diagnostic Imaging
• Physiology

Background:

• Ischemia and non-obstructive coronary artery stenosis (INOCA) often presents with normal wall motion on stress echocardiography (SE).
• Assessing cardiac mechanics in INOCA patients with reduced coronary flow velocity reserve (CVFR) requires further investigation.

Purpose of the Study:

• To evaluate cardiac mechanics in INOCA patients with reduced CVFR using 2DSTE during SE.
• To determine if reduced CVFR in INOCA is associated with altered cardiac function.

Main Methods:

• A prospective, international study involving 135 INOCA patients.
• High-dose dipyridamole SE combined with CVFR and 2DSTE assessment.
• Comparison of 2DSTE parameters between patients with normal (n=95) and abnormal (n=35) CVFR.

Main Results:

• High feasibility (98% for CVFR, 97% for 2DSTE) was observed.
• At peak SE, patients with abnormal CVFR showed significantly lower global longitudinal strain and layer-specific strain, and higher mechanical dispersion compared to those with normal CVFR.
• No significant differences in resting 2DSTE values were found between groups.

Conclusions:

• Simultaneous vasodilator SE, CVFR, and 2DSTE assessment is feasible in INOCA patients.
• Coronary microvascular dysfunction in INOCA is associated with impaired global and layer-specific cardiac deformation during stress.
• 2DSTE can identify subtle cardiac mechanical alterations in INOCA patients with reduced CVFR.