title: Protective effect of unstable angina in coronary artery bypass surgery.
abstract: OBJECTIVE
  To test the hypothesis that recent ischaemic episodes in unstable cases have a protective effect on coronary artery bypass graft (CABG) patients.
  
  
  METHODS
  Twenty unstable patients with ischaemic episodes within 3 days before operation were compared with 20 stable patients. Haemodynamic data were monitored up to the first postoperative day. Biochemical markers were measured up to the second postoperative day.
  
  
  RESULTS
  The cardiac index decreased at 1 and 6 h after declamping in the stable group (89% and 97% of baseline) but increased in unstable patients (104% and 122%, p =0.038 and 0.036, respectively). The depression in the right ventricular stroke work index was significantly attenuated in the unstable group (58%, 67% and 83% in stable and 90%, 97% and 117% in unstable patients, p = 0.027, 0.010 and 0.049 at 1 and 6 h after declamping and 1st POD). The release of cardiac troponin I (CTnI) and CK-MB was significantly lower in the unstable group at 6 h after declamping (5.6 +/- 2.9 and 19.0 +/- 6.3 microg/l in unstable vs 17.4 +/- 9.6 and 25.8 +/- 12.3 microg/l in stable patients, p = 0.000 and 0.039, respectively).
  
  
  CONCLUSIONS
  Recent unstable angina before CABG might act as an ischaemic preconditioning stimulus and could improve haemodynamic function and cellular viability. Delayed preconditioning most likely causes this protective effect.
authors.affiliation: Division of Cardiac Surgery, Tampere University Hospital, Finland.
authors.forename: Z K
authors.initials: ZK
authors.lastname: Wu
authors.forename: E
authors.initials: E
authors.lastname: Pehkonen
authors.forename: J
authors.initials: J
authors.lastname: Laurikka
authors.forename: L
authors.initials: L
authors.lastname: Kaukinen
authors.forename: E L
authors.initials: EL
authors.lastname: Honkonen
authors.forename: S
authors.initials: S
authors.lastname: Kaukinen
authors.forename: M R
authors.initials: MR
authors.lastname: Tarkka
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass; D005260:Female; D006334:Heart Function Tests; D006439:Hemodynamics; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology
chemical_list: D015415:Biomarkers