Patients with coronary slow flow exhibited significantly impaired resting global longitudinal strain (-18.37% vs -20.07%; P<0.001) compared to controls, but preserved contractile reserve during exercise with similar GLS augmentation (ΔGLS 3.73% vs 3.19%; P=0.154).
Case-Control (n=63)
No
Does symptom-limited treadmill exercise testing with 2D-STE reveal differences in myocardial contractile reserve between patients with coronary slow flow and normal controls?
Patients with coronary slow flow exhibit impaired resting longitudinal strain but preserved contractile reserve during exercise, suggesting the underlying microvascular dysfunction is functional and reversible rather than structural.
Absolute Event Rate: -18.37% vs -20.07%
p-value: p=<0.001
Patients with CSF exhibit distinct subclinical longitudinal dysfunction at rest, likely attributable to elevated resting microvascular resistance. However, the preservation of contractile reserve during physiological stress suggests that the underlying microvascular dysfunction is predominantly functional and reversible. 2D-STE provides incremental diagnostic value over conventional angiography in stratifying the pathophysiology of INOCA.
Li et al. (Mon,) conducted a case-control in Adults with angiographically defined coronary slow flow phenomenon (CSF), mean age approximately 58 years, with angina pectoris and no obstructive coronary artery disease (luminal stenosis <40%) (n=63). Coronary Slow Flow (CSF) condition assessed vs. Age- and sex-matched controls with normal coronary flow was evaluated on Left ventricular global longitudinal strain (GLS) at rest and peak exercise stress (p=<0.001). Patients with coronary slow flow exhibited significantly impaired resting global longitudinal strain (-18.37% vs -20.07%; P<0.001) compared to controls, but preserved contractile reserve during exercise with similar GLS augmentation (ΔGLS 3.73% vs 3.19%; P=0.154).