title: Clinical impact of coronary artery spasm in patients with no significant coronary stenosis who are experiencing acute coronary syndrome.
abstract: OBJECTIVE
  To clarify the clinical features of coronary artery spasm (CAS) with no significant coronary stenosis in patients with suspected acute coronary syndrome (ACS) in real practice.
  
  
  METHODS
  This is a retrospective observational study of patients with suspected ACS (n=645) based on symptoms, electrocardiographic changes, and/or positive cardiac biomarkers and vasospastic angina (VSA, n=90). ACS patients were divided into two groups: (1) organic ACS (n=515), culprit lesion ≥75% coronary stenosis with/without thrombosis; (2) spastic ACS (n=70), coronary stenosis <75%, either with positive acetylcholine (ACh) test (n=51) or without ACh test but verified spontaneous spasm (n=19). The study compared clinical characteristics among organic ACS, spastic ACS, and VSA.
  
  
  RESULTS
  One hundred and thirty suspected ACS patients had a coronary organic stenosis <75% (130/645, 20%). Seventy of those patients (70/130, 54%) were confirmed to have CAS, and these accounted for 11% of all ACS patients (70/645). The rate of cigarette smoking was highest in the spastic ACS. No spastic ACS patients died during their hospital stay or after discharge, whereas acute myocardial infarction occurred in 19%, aborted sudden cardiac death in 6%, multivessel spasm was provoked in 78%, and diffuse spasm was more frequently provoked than in the VSA group (82% vs. 62%).
  
  
  CONCLUSIONS
  CAS is not a rare cause of ACS. Although the prognosis of spastic ACS is good, there are occasional critical cases. An initial differential diagnosis including an ACh test is thus important to decide the treatment strategy of ACS.
authors.affiliation: Department of Cardiology and Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan. satoshin@kyumed.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Satoh
authors.forename: Soichiro
authors.initials: S
authors.lastname: Omura
authors.forename: Hiroko
authors.initials: H
authors.lastname: Inoue
authors.forename: Takahiro
authors.initials: T
authors.lastname: Mori
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Takenaka
authors.forename: Kotaro
authors.initials: K
authors.lastname: Numaguchi
authors.forename: Etsuo
authors.initials: E
authors.lastname: Mori
authors.forename: Akemi
authors.initials: A
authors.lastname: Aso
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nakamura
authors.forename: Koji
authors.initials: K
authors.lastname: Hiyamuta
mesh_terms: D000109:Acetylcholine; D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography; D003329:Coronary Vasospasm / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D006334:Heart Function Tests / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
chemical_list: D000109:Acetylcholine