Association between vasospastic angina and comprehensive coronary computed tomography angiography findings

Coronary computed tomography angiography (CCTA) provides anatomical coronary artery visualization and tissue characterization. Prior studies showed that elevated perivascular fat attenuation index (FAI) around the right coronary artery (RCA) correlates with vasospastic angina (VSA). Recurrent vasospasm potentially induces myocardial injury and fibrosis detectable as an increased myocardial extracellular volume fraction (ECV). However, the ability of comprehensive CCTA assessment to predict VSA remains elusive.

We investigated the correlation between VSA and CCTA findings including FAI-RCA and ECV.

We enrolled consecutive patients who underwent CCTA with an ECV quantification protocol followed by invasive spasm provocation test (SPT). Patients with hemodialysis were excluded. VSA was defined as a composite of chest symptoms, ischemic ECG changes, and severe stenosis or occlusion in the CAG induced by SPT. CCTA images were post-processed to quantify ECV and FAI-RCA.

A total of 100 patients were included (55 (55.0%) men; 65.3±11.8 years old) in the final analysis. VSA was diagnosed in 27 patients. A Multivariable Logistic Regression analysis showed that differences in ECV value between endocardium and epicardium, average CT value in left ventricle (avg-CTLV) and FAI-RCA > -70.95HU (cut off value derived from receiver operating characteristic curve analysis) were independently associated with VSA [Odds ratio; 1.13 (95% confidence interval; 1.01-1.26), 0.94 (0.89-0.99), 4.47 (1.62-12.40), respectively. All P<0.05].

Our results demonstrated that CCTA-derived ECV and FAI-RCA could help identify patients at high risk for VSA. ECV index was significantly associated with VSA independent of FAI, suggesting myocardial fibrosis imaging provides additional diagnostic value to adipose tissue inflammation.