Carotid artery intima-media thickness correlates with intravascular ultrasound parameters in patients with slow coronary flow

Background Coronary slow flow (CSF) phenomenon is characterized by delayed opacification of coronary vessels in a normal coronary angiogram. Although clinical and pathological features have been previously described, the underlying pathophysiology has not been fully elucidated. We aimed to determine and compare the carotid intima-media thickness (CIMT) values of SCF patients and healthy subjects, and to correlate patients’ values with intimal thickness and TIMI frame counts of their coronary arteries (assessed by intravascular ultrasound). Methods The study population consisted of 50 patients with SCF [38(76%) male, aged 53 ± 7 years] and 40 normal subjects [22(55%) male, aged 51 ± 8 years]. CIMT values, intravascular ultrasonographies and TIMI frame counts of the patients, and CIMT of the controls were investigated. Results Upon intravascular ultrasonography investigation, the common finding was longitudinally extended massive calcification throughout the epicardial coronary arteries in 44 (88%) of patients. Mean coronary intimal thickness was 0.52 ± 0.1 mm. CIMT was significantly increased in SCF patients than controls (0.84 ± 0.14 vs. 0.66 ± 0.13, p < 0.0001). Besides, CIMT was significantly correlated with coronary intima-media thickness. TIMI frame counts were positively correlated with CIMT and coronary intimal thickness (p < 0.05 and p < 0.05 respectively). Conclusion These results support the theory that SCF is the result of coronary atherosclerosis which is the part of systemic involvement.