title: The natural history of myocardium awaiting revascularisation in patients with impaired left ventricular function.
abstract: OBJECTIVE
  Our aim was to follow changes in myocardial function and physiology in patients awaiting coronary artery bypass surgery (CABG) and relate changes to post-revascularisation functional response.
  
  
  RESULTS
  In 21 patients with CAD and LV dysfunction, myocardial glucose utilisation (MGU) and blood flow (MBF) were measured with positron emission tomography using F-18-fluorodeoxyglucose and oxygen-15-labelled water. Left ventricular function, MGU, and MBF were re-assessed after one year, immediately prior to CABG. At baseline, dysfunctional myocardium displayed a reduction in MGU, hyperaemic MBF, and coronary vasodilator reserve (CVR) compared to normally functioning muscle. In the year preceding CABG, the overall wall motion score index increased (2.09 +/- 0.65 vs. 2.3 +/- 0.7, p=0.0001) and the LV ejection fraction decreased (30.6 +/- 11.1% vs. 27.3 +/- 11.5%, p<0.001). LVEF fell in 14 patients (28.7 +/- 9.4 vs. 23.8, p<0.0001). Aggregate regional wall motion worsened in 15 patients. In contrast to myocardium displaying stable function at echocardiography, myocardium with evidence of deterioration showed a parallel decrease in hyperaemic MBF and CVR (1.57 +/- 0.67 vs. 1.19 +/- 0.7 ml/min/g, [p=0.004] and 1.9 +/- 0.75 vs. 1.33 +/- 0.6, [p=0.005], respectively). Such myocardium displayed attenuated recovery postoperatively (21/68 [31%] LV segments) versus 'waiting-time' stable myocardium (98/169 [58%], p=0.0002).
  
  
  CONCLUSIONS
  Delayed revascularisation in ischaemic left ventricular impairment results in declining function and a reduced likelihood of contractile improvement.
authors.affiliation: Department of Cardiology, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK. michael.pitt@heartsol.wmids.nhs.uk
authors.forename: Michael
authors.initials: M
authors.lastname: Pitt
authors.forename: David
authors.initials: D
authors.lastname: Dutka
authors.forename: Domenico
authors.initials: D
authors.lastname: Pagano
authors.forename: Paolo
authors.initials: P
authors.lastname: Camici
authors.forename: Robert
authors.initials: R
authors.lastname: Bonser
mesh_terms: D001026:Coronary Artery Bypass; D003326:Coronary Circulation / Q000502:physiology; D004452:Echocardiography; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000601:surgery*; D009204:Myocardial Revascularization; D009206:Myocardium; D011182:Postoperative Care; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D018487:Ventricular Dysfunction, Left / Q000209:etiology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18