title: Outcome of bypass surgery in patients with chronic ischemic left ventricular dysfunction. Predictive value of MR imaging.
abstract: OBJECTIVE
  To determine the preoperative findings of MR imaging of the left ventricle (LV) that could best predict the functional outcome of the LV after surgical revascularization.
  
  
  METHODS
  Patients with angina pectoris, previous myocardial infarction, and dysfunction of the LV, and who had a preoperative cine MR, were re-evaluated after bypass surgery with MR in a study on the effects of revascularization after mean 22 months.
  
  
  RESULTS
  Angina pectoris was relieved in all patients except one, but the maximum workload during the exercise test was increased in only 3 patients. Coronary angiography showed that 37 of 45 (82%) of the distal anastomoses were open. The LV ejection fraction was the same before and after operation both at angiography and MR imaging. MR showed LV end-diastolic volume to be increased from 190 +/- 50 ml to 250 +/- 70 ml. Compared to angiography, MR provided additional information regarding myocardial wall thickness and function, and the size of myocardial infarction. Improvement in systolic wall thickening was seen in 65% of the segments that had had an end-diastolic wall thickness (EDWT) greater than 15 mm before operation, while only 4% of the segments with EDWT < 6 mm improved. In the wall thickness range of 6-15 mm, MR was unable to predict the functional outcome of the LV.
  
  
  CONCLUSIONS
  Preoperative MR findings of thick myocardial walls with poor function seem predictive of improved function after revascularization. When the LV wall thickness is less than 6 mm, no improvement should be expected.
authors.affiliation: Department of Radiology, National Hospital, Oslo, Norway.
authors.forename: N E
authors.initials: NE
authors.lastname: Kløw
authors.forename: H J
authors.initials: HJ
authors.lastname: Smith
authors.forename: L
authors.initials: L
authors.lastname: Gullestad
authors.forename: E
authors.initials: E
authors.lastname: Seem
authors.forename: K
authors.initials: K
authors.lastname: Endresen
mesh_terms: D000368:Aged; D000790:Angiocardiography / Q000379:methods / Q000706:statistics & numerical data; D016009:Chi-Square Distribution; D002908:Chronic Disease; D001026:Coronary Artery Bypass; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D011379:Prognosis; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery