title: Coronary plaque rupture in patients with myocardial infarction after noncardiac surgery: frequent and dangerous.
abstract: OBJECTIVE
  The pathophysiology of acute coronary syndromes (ACS) after noncardiac surgery is not established yet. Thrombosis over a vulnerable plaque or decreased oxygen supply secondary to anemia or hypotension may be involved. The purpose of this study was to investigate the pathophysiology of ACS complicating noncardiac surgery.
  
  
  METHODS
  Clinical and angiographic data were prospectively recorded into a database for 120 consecutive patients that had an ACS after noncardiac surgery (PACS), for 120 patients with spontaneous ACS (SACS), and 240 patients with stable coronary artery disease (CAD). Coronary lesions with obstructions greater than 50% were classified based on two criteria: Ambrose's classification and complex morphology. The presence of Ambrose's type II or complex lesions were compared between the three groups.
  
  
  RESULTS
  We analyzed 1470 lesions in 480 patients. In PACS group, 45% of patients had Ambrose's type II lesions vs. 56.7% in SACS group and 16.4% in stable CAD group (P<0.001). Both PACS and SACS patients had more complex lesions than patients in stable CAD group (56.7% vs. 79.2% vs. 31.8%, respectively; P<0.001). Overall, the independent predictors of plaque rupture were being in the group PACS (P<0.001, OR 2.86; CI, 1.82-4.52 for complex lesions and P<0.001, OR 3.43; CI, 2.1-5.6 for Ambrose's type II lesions) or SACS (P<0.001, OR 8.71; CI, 5.15-14.73 for complex lesions and P<0.001, OR 5.99; CI, 3.66-9.81 for Ambrose's type II lesions).
  
  
  CONCLUSIONS
  Nearly 50% of patients with perioperative ACS have evidence of coronary plaque rupture, characterizing a type 1 myocardial infarction.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, Interdisciplinary Medicine in Cardiology Unit, Brazil. danielle.gualandro@incor.usp.br
authors.forename: Danielle Menosi
authors.initials: DM
authors.lastname: Gualandro
authors.forename: Carlos Augusto
authors.initials: CA
authors.lastname: Campos
authors.forename: Daniela
authors.initials: D
authors.lastname: Calderaro
authors.forename: Pai Ching
authors.initials: PC
authors.lastname: Yu
authors.forename: Andre Coelho
authors.initials: AC
authors.lastname: Marques
authors.forename: Adriana Feio
authors.initials: AF
authors.lastname: Pastana
authors.forename: Pedro Alves
authors.initials: PA
authors.lastname: Lemos
authors.forename: Bruno
authors.initials: B
authors.lastname: Caramelli
mesh_terms: D054058:Acute Coronary Syndrome / Q000209:etiology*; D000368:Aged; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000000981:diagnostic imaging; D058226:Plaque, Atherosclerotic / Q000150:complications* / Q000503:physiopathology; D011446:Prospective Studies; D011859:Radiography; D012421:Rupture / Q000150:complications / Q000503:physiopathology*; D013514:Surgical Procedures, Operative / Q000009:adverse effects*