Thromboembolic risk scores in patients with non-obstructive coronary architecture with and without coronary slow flow: A case-control study

Aim: Coronary slow flow phenomenon (CSFP) detected on coronary angiography (CA) has been related to poor prognosis. We sought to examine the relationship between thromboembolic risk scores, routinely used in cardiology practice, and CSFP.

Methods: This single-center, retrospective, case-control study comprised 505 individuals suffering from angina and had verified ischemia between January 2021 and January 2022. Demographic and laboratory parameters were obtained from the hospital database. The following risk scores were calculated; CHA₂DS₂-VASc, M-CHA₂DS₂-VASc, CHA₂DS₂-VASc-HS, R₂-CHA₂DS₂-VASc, M-R₂-CHA₂DS₂-VASc, ATRIA, M-ATRIA, M-ATRIA-HSV. The overall population was divided into two groups; coronary slow flow and coronary normal flow. Multivariable logistic regression was performed to compare risk scores between patients with and without CSFP. Pairwise comparisons were then undertaken to test performance in determining CSFP.

Results: The mean age was 51.7 ± 10.7 years, of whom 63.2% were male. CSFP was detected in 222 patients. Those with CSFP had higher rates of male gender, diabetes, smoking, hyperlipidemia, and vascular disease. All scores were higher in CSFP patients. Multivariable logistic regression analysis found that CHA₂DS₂-VASc-HS score was the most powerful determinant of CSFP among all risk schemes (for each one-point increase in score OR = 1.90, p < 0.001; for score of 2-3 OR = 5.20, p < 0.001; for score of >4 OR = 13.89, p < 0.001). Also, the CHA₂DS₂-VASc-HS score provided the best discriminative performance, with a cut-off value of ≥2 in identifying CSFP (AUC = 0.759, p < 0.001).

Conclusion: We showed that thromboembolic risk scores may be associated with CSFP in patients with non-obstructive coronary architecture who underwent CA. The CHA₂DS₂-VASc-HS score had the best discriminative ability.