Visual Estimates of Coronary Slow Flow Are Not Associated With Invasive Wire-Based Diagnoses of Coronary Microvascular Dysfunction.

Background: Coronary slow flow (CSF) by invasive coronary angiography is frequently understood to be an indicator of coronary microvascular dysfunction (CMD) in patients with ischemia with nonobstructive coronary arteries. However, the relationship between visual estimates of CSF and quantitative wire-based invasive diagnosis of CMD is uncertain.

Methods: We prospectively enrolled adults aged ≥18 years with stable ischemic heart disease who were referred for invasive coronary angiography.