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

Highlights

• Coronary slow flow phenomenon (CSFP) is an angiographic finding related to microvascular disease

• Individual parameters of thromboembolic risk scores have been linked to CSFP.

• The majority of the risk schemes were higher in individuals with CSFP than in those with coronary normal flow.

• CHA₂DS₂-VASc-HS score outperformed all others in determining CSFP for patients with non-obstructive coronary artery architecture.

• Among the individual parameters of the CHA₂DS₂-VASc-HS score, hyperlipidemia was the strongest determinant of CSFP.

Abstract

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.

Introduction

Coronary slow flow phenomenon (CSFP) is an angiographic finding associated with coronary microvascular disease, characterized by the slow distal flow of contrast dye in the absence of obstructive coronary artery disease (CAD). Previous studies have reported a prevalence of 1–34% [1]. Although the underlying processes are poorly understood, endothelial dysfunction, inflammatory response, subclinical atherosclerosis, blood cell/platelet abnormalities, impaired microvascular reserve function, and genetic factors are the most prominent initiators [2]. The relationships of CSFP with recurrent angina-like symptoms, readmission to the hospital, arrhythmia, and a poor prognosis [3] further reinforce the notion that it is a clinically significant angiographic event. Furthermore, the fact that risk factors for CAD, such as age [4], gender [4], hypertension [5], diabetes mellitus (DM) [6], dyslipidemia [7], smoking [8], and end-stage renal disease [9], may play a role in the development of CSFP, even in individuals with non-obstructive epicardial coronary atherosclerosis, suggests that the entity is at least a part of the early atherosclerotic process. Despite all of these supportive implications, there is still a lack of comprehensive approach to better understanding the pathophysiology of CSFP.

The two most important scoring schemes used in clinical practice to determine the risk of stroke in patients with non-valvular atrial fibrillation (AF) are; CHA₂DS₂-VASc (Congestive heart failure, Hypertension, Age [≥65 = 1 point, ≥75 = 2 points], Diabetes mellitus, Stroke/transient ischemic attack [TIA] [2 points], and Vascular disease [peripheral arterial disease, previous myocardial infarction, and aortic atheroma], Sex category [female sex = 1 point]), and anticoagulation and risk factors in atrial fibrillation (ATRIA). Moreover, subsequent research has indicated that these scores and their derivatives are related to a wide range of clinical outcomes, including the severity of CAD and major adverse cardiovascular events [[10], [11], [12]].

In patients with documented ischemia on non-invasive imaging and who underwent coronary angiography (CA) for suspected ischemic heart disease, the aim of the present study is twofold; (i) to investigate the association of coronary flow patterns with various thromboembolic risk scores, which include certain parameters associated with CSFP and (ii) to compare the discriminative power of these scoring schemes for slow coronary flow.