Pre‐percutaneous Coronary Intervention Pericoronary Adipose Tissue Attenuation Evaluated by Computed Tomography Predicts Global Coronary Flow Reserve After Urgent Revascularization in Patients With Non–ST‐Segment–Elevation Acute Coronary Syndrome

BACKGROUND: Impaired global coronary flow reserve (g‐CFR) is related to worse outcomes. Inflammation has been postulated to play a role in atherosclerosis. This study aimed to evaluate the relationship between pre‐procedural pericoronary adipose tissue inflammation and g‐CFR after the urgent percutaneous coronary intervention in patients with first non–ST‐segment–elevation acute coronary syndrome. METHODS AND RESULTS: Phase‐contrast cine‐magnetic resonance imaging was performed to obtain g‐CFR by quantifying coronary sinus flow at 1 month after percutaneous coronary intervention in a total of 116 first non–ST‐segment–elevation acute coronary syndrome patients who underwent pre‐percutaneous coronary intervention computed tomography angiography. On proximal 40‐mm segments of 3 major coronary vessels on computed tomography angiography, pericoronary adipose tissue attenuation was assessed by the crude analysis of mean computed tomography attenuation value. The patients were divided into 2 groups with and without impaired g‐CFR divided by the g‐CFR value of 1.8. There were significant differences in age, culprit lesion location, N‐terminal pro‐B‐type natriuretic peptide levels, high‐sensitivity C‐reactive protein (hs‐CRP) levels, mean pericoronary adipose tissue attenuation between patients with impaired g‐CFR and those without (g‐CFR, 1.47 [1.16, 1.68] versus 2.66 [2.22, 3.28]; P<0.001). Multivariable logistic regression analysis revealed that age (odds ratio [OR], 1.060; 95% CI, 1.012–1.111, P=0.015) and mean pericoronary adipose tissue attenuation (OR, 1.108; 95% CI, 1.026–1.197, P=0.009) were independent predictors of impaired g‐CFR (g‐CFR <1.8). CONCLUSIONS: Mean pericoronary adipose tissue attenuation, a marker of perivascular inflammation, obtained by computed tomography angiography performed before urgent percutaneous coronary intervention, but not hs‐CRP, a marker of systemic inflammation was significantly associated with g‐CFR at 1‐month after revascularization. Our results may suggest the pathophysiological mechanisms linking perivascular inflammation and g‐CFR in patients with non–ST‐segment–elevation acute coronary syndrome.