Nitrates vs. Other Types of Vasodilators and Clinical Outcomes in Patients with Vasospastic Angina: A Propensity Score-Matched Analysis

Abstract

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.

Management of Coronary Artery Spasm

“…26 Several subsequent studies assessed the effects of nitrates on clinical outcomes in VSA patients, usually reporting increased or neutral risk of cardiovascular events compared with no nitrate therapy, as summarised in Table 1. [30][31][32][33][34][35] The lack of beneficial effects of nitrates on CAS-related events may be related to a loss of their vasodilator effects on constricted epicardial arteries due to the development of tolerance. 36 Furthermore, continuous exposure to nitrates may be associated with an impairment of endothelial function related to their release of nitric oxide molecules.…”

What More Can Be Delivered to Future Patients with Coronary Syndromes?

“…Teragawa et al [ 6 ] identified active smoking as a possible risk factor associated with the increase in the index of microcirculatory resistance (IMR) for patients who underwent an invasive microvascular vasodilatory function test, showing that IMR differed according to the coronary artery branches and types of coronary spasm. Kim et al [ 7 ] documented that the chronic use of nitrates in patients with vasospastic angina, relative to other types of vasodilators, such as nicorandil, was associated with an increased risk of adverse clinical outcomes in a prospective nationwide registry database.…”