Vasospastic angina (VA) is a functional disease caused by the alteration of vasomotor tone. We investigated the association of hyperthyroidism with the development and prognosis of VA. Study data were obtained from a prospective multicenter registry that included patients who had symptoms suggestive of VA. Coronary angiography and an ergonovine provocation test were performed, and patients were classified into a VA and a non-VA group. Among 1239 patients with suspected VA, 831 patients were classified in the VA group. Hyperthyroidism was more common in the VA group than in the non-VA group (10.0% vs. 3.7%, p < 0.001). After adjusting for confounding factors, hyperthyroidism was independently associated with a 3.27-fold increased risk of VA. Especially in women, hyperthyroidism was associated with a 4.38-fold higher risk of VA. All-cause death rates did not differ according to the presence or absence of hyperthyroidism. Hyperthyroidism is independently associated with the occurrence of VA especially in women but did not affect the total death in VA patients. Clinicians need to be aware of the role of thyroid function in patients with suspected VA.

Although vasodilators are widely used in patients with vasospastic angina (VA), few studies have compared the long-term prognostic effects of different types of vasodilators. We investigated the long-term effects of vasodilators on clinical outcomes in VA patients according to the type of vasodilator used. Study data were obtained from a prospective multicenter registry that included patients who had symptoms suggestive of VA. Patients were classified into two groups according to use of nitrates (n = 239) or other vasodilators (n = 809) at discharge. The composite clinical events rate, including acute coronary syndrome (ACS), cardiac death, new-onset arrhythmia (including ventricular tachycardia and ventricular fibrillation), and atrioventricular block, was significantly higher in the nitrates group (5.3% vs. 2.2%, p = 0.026) during one year of follow-up. Specifically, the prevalence of ACS was significantly more frequent in the nitrates group (4.3% vs. 1.5%, p = 0.024). After propensity score matching, the adverse effects of nitrates remained. In addition, the use of nitrates at discharge was independently associated with a 2.69-fold increased risk of ACS in VA patients. In conclusion, using nitrates as a vasodilator at discharge can increase the adverse clinical outcomes in VA patients at one year of follow-up. Clinicians need to be aware of the prognostic value and consider prescribing other vasodilators.