Comparison of systemic immune-inflammation index levels in patients with isolated coronary artery ectasia versus patients with obstructive coronary artery disease and normal coronary angiogram.

Coronary artery ectasia (CAE) is associated with increased risk of mortality, equivalent to that of patients with obstructive coronary artery disease (CAD). Considering the role of inflammation in the pathogenesis of CAE, we aimed to investigate whether there is an association between systemic immune-inflammation index (SII) and isolated CAE. The study population included 510 patients of which 170 patients with isolated CAE, 170 patients with obstructive CAD and 170 patients with normal coronary angiograms (NCA). The severity of CAE was determined according to the Markis classification. Patients with isolated CAE had significantly higher SII values compared to those with obstructive CAD and NCA [median 550 IQR (404-821), median 526 IQR (383-661), and median 433 IQR (330-555), respectively, p  < .001]. In multivariate analysis, SII (OR 1.032, 95% CI 1.020-1.044, p  = .003), male gender (OR 2.083, p  = .008), eGFR (OR 0.979, p  = .016), and CRP (OR 1.105, p  = .005) were independent factors of isolated CAE. Moreover, in the Spearman correlation analysis, there was a moderate but significant positive correlation between SII and CRP ( r  = 0.379, p  < .001). In conclusion, higher SII levels were independently associated with the presence of isolated CAE. This result suggests that a more severe inflammatory process may play a role in the development of this variant of CAD.