Prognostic significance of vascular endothelial dysfunction in patients with vasospastic angina

BACKGROUND Vascular endothelial dysfunction (VED) is thought to contribute to the pathogenesis of vasospastic angina (VSA), but its prognostic significance remains unclear. AIM To evaluate whether clinical characteristics and prognosis differ according to the presence or absence of VED in patients with VSA. METHODS We retrospectively analyzed 244 patients (mean age 67 years, 107 men) admitted for chest pain screening and diagnosed with VSA by spasm provocation testing. Vascular endothelial function was evaluated using brachial artery flow-mediated dilation (FMD). Patients were divided into a high-FMD group (≥ 3.7%; n = 123) and a low-FMD group (FMD-L, < 3.7%; n = 121). VSA was defined as ≥ 90% coronary vasoconstriction on angiography with chest symptoms and/or electrocardiographic changes during spasm provocation testing. Focal spasm was defined as spasm localized within a single American Heart Association coronary segment. Major adverse cardiovascular events included cardiac death and cardiovascular rehospitalization. RESULTS Baseline characteristics, except for age (P = 0.017), did not differ significantly between groups. Focal spasm tended to be more frequent in the FMD-L group (43% vs 32%, P = 0.069). Kaplan-Meier analysis showed a significantly lower major adverse cardiovascular events-free survival rate in the FMD-L group (log-rank P = 0.004). Multivariate Cox regression identified FMD-L (P = 0.025) and older age (P = 0.026) as independent prognostic factors, whereas focal spasm was not significant (P = 0.157). CONCLUSION VED is an independent predictor of adverse outcomes in VSA. Evaluation of endothelial function may provide valuable prognostic information in patients with VSA.