Impaired Coronary Microcirculation and Myocardial Systolic Function: A Narrative Review on Non-Invasive Assessment in...

Coronary microvascular dysfunction (CMD) is presently recognized as a condition characterized by a reduction in coronary blood flow. CMD is associated with poor cardiac outcomes, and mounting evidence suggests that coronary microcirculation may be impaired in various cardiology pathologies. Non-invasive assessment of CMD remains challenging, and several imaging modalities-positron emission tomography (PET), computed tomography (CT), cardiac magnetic resonance (CMR), myocardial contrast echocardiography (MCE), and transthoracic Doppler echocardiography (TTE)-are proven to quantify coronary flow reserve (CFR) and myocardial blood flow (MBF), both valuable markers of CMD. However, each modality is limited by availability, standardization, and diagnostic utility. Furthermore, a growing number of studies have attempted to correlate CMD indices with systolic myocardial function markers, such as left ventricular ejection fraction, global longitudinal strain, and myocardial work indices. This review refers to the current evidence on CMD imaging and examines the association between CMD indices and systolic function in cardiovascular diseases. Understanding the impact of CMD on myocardial function is essential, as it highlights the coronary microcirculation impairment pathway as a potential target for therapeutic strategies.