Background:
The clinical significance of non-obstructive coronary artery disease (CAD) is still controversial.
Purpose: The aim of this study was to compare CAD distribution and relation to risk factors in non-significant and significant CAD.
Subjects and methods: A retrospective analysis of a prospectively updated database was performed. Risk factors including body mass index (BMI), total cholesterol, triglycerides, high density lipoprotein (HDL) low density lipoprotein (LDL), smoking, diabetes mellitus (DM), hypertension (HTN) and family history were collected. CCTA was assessed for the presence of non-significant (1-50% stenosis) and significant (>51% stenosis) stenosis and CAD distribution (15 coronary segments). The correlation between CAD distribution and the different risk factors was studied using multiple logistic regressions.
Results:
The study included 1877 consecutive patients (mean age 50 years, 66.32% males) undergoing CCTA in the CPU (2006 - 2013). CCTA results: no CAD : 1024 patients (54.56 %), non-significant CAD: 698 patients (37.19%), significant CAD: 155 patients (8.25%). Overall, both significant and non significant CAD were mostly present in the proximal segments (proximal and mid LAD (segments 6 & 7) proximal and mid RCA (segments 1& 2) and proximal and mid CX (segments 11 & 12) in descending order (Fig 1). Overall CAD (non-significant and significant) were highly and positively related with age (p<0.001), gender (<0.001) BMI (p<0.001), HTN (p<0.001), smoking (p<0.001), DM (p<0.001) and negatively related with HDL (p<0.0001). Patients with HTN and DM demonstrated similar disease segmental distribution with a trend for higher % of significant CAD (although not statistically significant).
Conclusions:
Both significant and non significant CAD were similarly and preferentially located in the proximal segments of the three major coronary arteries. Classical risk factors apart from triglycerides, LDL and family history were significant and positively related to any documented CAD. These observations might suggest a continuum between non-significant and significant CAD.
