Abstract 12505: Clinical Characteristics of Patients With Vasospastic Angina Subjected to the Spasm Provocation Test Involving the Unavoidable Use of Nitroglycerin

Abstract

Introduction: Multivessel spasm (MVS) has a prognostic impact in patients with vasospastic angina (VSA). Thus, assessing for the presence of MVS in both left coronary artery and right coronary artery is preferable in the spasm provocation test (SPT). The use of nitroglycerin is necessary to avoid the complications related to SPT; however, this unavoidable use of NTG (U-NTG) may decrease the detection of MVS. Hypothesis: We investigated the frequency of U-NTG during SPT and clarified the clinical characteristics in VSA patients, with U-NTG during STP. Methods: Total 142 patients with positive SPT were evaluated. A positive SPT was defined as >90% constriction in coronary arteries, accompanied by the chest symptoms and/or ischemic ST-T changes. When a coronary spasm occurred, we usually waited for the spontaneous relief of the coronary spasm. However, if a prolonged coronary spasm or unstable hemodynamics occurred, NTG was administered to relieve the coronary spasm promptly (U-NTG). Even when U-NTG was administered in one coronary artery, an additional SPT was performed on another coronary artery. The patients were divided into two groups according to U-NTG: U-NTG(+) (n = 42) and U-NTG(-), (n = 100). The clinical characteristics and frequencies of MVS and complications (unstable hemodynamics) during the SPT were compared between the groups. Results: Except for smoking status, all other clinical characteristics status did not differ significantly between the groups. More current smokers were observed in the U-NTG(+) group (29%) compared with that in the U-NTG(-) group (12%, p = 0.03). The frequency of MVD did not vary significantly between the groups, with 64% in the U-NTG(+) and 52% in the U-NTG(-). No significant difference was found between the groups in the frequency of severe complications during SPT, with 5% in U-NTG(+) and 3% in U-NTG(-). In U-NTG(+), the positive induction of coronary spasm in another coronary artery was 40% (17/42). Conclusions: Our results show that U-NTG occurred in ~30% of VSA patients, especially in current smokers, and that it did not decrease the detection of MVS and prevented severe complications during SPT. Therefore, U-NTG is acceptable during SPT, after which, another test may be performed to assess the presence of MVS.