title: Coronary artery spasm as a frequent cause of acute coronary syndrome: The CASPAR (Coronary Artery Spasm in Patients With Acute Coronary Syndrome) Study.
abstract: OBJECTIVE
  This study was conducted to clarify the incidence of coronary spasm in emergency patients with suspected acute coronary syndrome (ACS) and acute chest pain at rest.
  
  
  BACKGROUND
  Chest pain at rest is a frequent symptom in the emergency room. Acute coronary syndrome is suspected in patients with elevation of cardiac markers, ischemic electrocardiographic changes, or simply typical clinical symptoms of unstable (usually resting) angina. However, of all patients with suspected ACS who undergo coronary angiography, up to 30% have nonobstructed coronary arteries. We sought to clarify how many of these patients suffer from coronary spasm as a possible cause of their chest pain.
  
  
  METHODS
  In a prospective study from June to December 2006, all patients with suspected ACS who underwent coronary angiography and had no culprit lesion underwent intracoronary provocation with acetylcholine. The ACH testing was considered positive at a vasoconstriction of >/=75% relative to the diameter after intracoronary nitroglycerine when the initially reported symptoms could be reproduced.
  
  
  RESULTS
  Of 488 consecutive patients, 138 had no culprit lesion (28%). Twenty-two were found to have another diagnosis. The ACH testing was performed in 86 of the remaining 116 patients. In 42 patients, coronary spasm was verified (49%).
  
  
  CONCLUSIONS
  Every fourth patient with ACS had no culprit lesion. Coronary spasm could be documented in nearly 50% of the patients tested by ACH. Coronary spasm is a frequent cause of ACS and should regularly be considered as a differential diagnosis.
authors.affiliation: Department of Cardiology and Pulmology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Ong
authors.forename: Anastasios
authors.initials: A
authors.lastname: Athanasiadis
authors.forename: Stephan
authors.initials: S
authors.lastname: Hill
authors.forename: Holger
authors.initials: H
authors.lastname: Vogelsberg
authors.forename: Matthias
authors.initials: M
authors.lastname: Voehringer
authors.forename: Udo
authors.initials: U
authors.lastname: Sechtem
mesh_terms: D000109:Acetylcholine; D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000209:etiology*; D000368:Aged; D000787:Angina Pectoris / Q000209:etiology / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D017023:Coronary Angiography; D003329:Coronary Vasospasm / Q000150:complications*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D000109:Acetylcholine