Association of vasospastic angina with myocardial bridging and pericoronary adipose tissue attenuation on computed tomography angiography

Abstract Background Recent studies have suggested that vasospastic angina (VSA) is associated with myocardial bridging (MB). The relationship between VSA and pericoronary adipose tissue (PCAT) inflammation has also been reported but still remains to be determined. Purpose We investigated clinical and coronary computed tomography angiographic (CCTA) features in patients with VSA diagnosed by spasm provocation test (SPT). Methods We retrospectively studied patients with clinically suspected VSA who underwent both SPT with intracoronary acetylcholine administration and CCTA within three months before SPT at Tsuchiura Kyodo General Hospital. PCAT inflammation was evaluated on CCTA images by fat attenuation index (FAI) which has been recently used as a novel biomarker of coronary inflammation. In FAI analysis, we measured FAI of the proximal segments not only for 4mm (FAI4mm) but also for the inner and thinner 2mm pericoronary adipose tissue layer from the vessel wall (FAI2mm), since FAI2mm has been reported to provide better discriminating efficacy for VSA diagnosis than FAI4mm. We also evaluated the presence or absence of MB and its features including length, depth and location on CCTA images. Results A total of 172 patients were studied and VSA was diagnosed in 39.0% (67/172) of patients by SPT according to the latest guideline. Male (74.6% vs 49.5%, P=0.001), smoking history (74.6% vs 48.6%, P=0.001) were more frequent, and prevalence of CCTA-defined MB (47.8% vs 34.3%, P=0.082) and RCA-FAI2mm (-68.73 HU vs -73.35 HU, P<0.001) were higher in patients with versus without VSA. In multivariable analysis, presence of CCTA-defined MB (odds ratio [OR] 2.56, 95% confidence interval [CI] 1.26-5.19, P=0.0095), RCA-FAI2mm (OR 1.05, 95% CI 1.01-1.09, P=0.025), and smoking (OR 3.40, 95% CI 1.57-7.36, P=0.0019) were independently associated with VSA. A combination of high RCA-FAI2mm (≥-68.93HU, the best cut-off obtained by ROC analysis with AUC of 0.64, 95% CI 0.551 - 0.728), smoking history and existence of MB could predict VSA with 73.7% of probability, while an absence of all 3 covariates could exclude VSA with 85.3% of probability. Conclusion CCTA-defined MB, high RCA-FAI2mm and smoking were independently predictive of VSA.