The relationship between coronary slow flow phenomenon and coronary calcium score

Coronary slow flow phenomenon (CSFP) is an angiographic finding characterized by delayed distal vessel opacification without any significant epicardial coronary artery disease. Several studies have suggested that CSFP might be a form of atherosclerosis. The present study was aimed to investigate the relationship between CSFP and coronary artery calcification, which is one of the clear-cut indicators of coronary atherosclerotic plaque, by using computerized tomography.

Fifty-five patients were included in the study. The coronary arteries of all patients were shown by angiography to be normal. Coronary slow flow (CSF) patterns were evaluated by the thrombolysis in myocardial infarction frame count (TFC) method. Patients with normal coronary arteries and CSF were allocated into the CSF group, and patients with normal coronary arteries and normal coronary flow were allocated into the control group. Coronary artery calcium (CAC) score was measured in 28 patients with CSF and in 27 controls by 64-slice computerized tomography.

The CSF and control groups were similar with respect to age, gender, smoking status, presence of hypertension and diabetes mellitus, cholesterol profiles, and Framingham risk scores (p>0.05). The CSF and control groups were not significantly different with respect to CAC score (p>0.05). Sub-group analysis of cardiac risk factors in patients with or without coronary artery calcification revealed that advanced age and low high density lipoprotein (HDL) levels were significantly associated with coronary artery calcification. There wasn't any relationship between coronary slow flow and cardiac risk factors or coronary calcium scores.

In the present study, no association was found between the CSFP and calcified atherosclerosis. Additionally, it was demonstrated that, among the cardiac risk factors, advanced age and low HDL levels were associated with coronary artery calcification.