title: Why do patients with ischemic cardiomyopathy and a substantial amount of viable myocardium not always recover in function after revascularization?
abstract: OBJECTIVE
  In patients with ischemic cardiomyopathy and a substantial amount of dysfunctional but viable myocardium, myocardial revascularization may improve left ventricular ejection fraction. The aim of this study was to evaluate why not all patients with a substantial amount of viable tissue recover in function after revascularization.
  
  
  METHODS
  A total of 118 consecutive patients with a depressed left ventricular ejection fraction (on average 29% +/- 6%) due to chronic coronary artery disease underwent myocardial revascularization. Before revascularization all patients underwent dobutamine stress echocardiography to assess regional dysfunction, left ventricular volumes, and myocardial viability as well as radionuclide ventriculography to determine the left ventricular ejection fraction. Next, 3 to 6 months after revascularization, the left ventricular ejection fraction and regional contractile function were reassessed. Improvement of left ventricular ejection fraction > or = 5% following revascularization was considered clinically significant.
  
  
  RESULTS
  Dobutamine stress echocardiography revealed that 489 (37%) of the 1329 dysfunctional segments were viable. A total of 61 (52%) patients had a substantial amount of viable myocardium (> or = 4 viable segments). In these 61 patients the global function was expected to recover > or = 5% after revascularization. However, left ventricular ejection fraction did not improve in 20 (33%) of 61 patients despite the presence of substantial viability. Clinical characteristics and echocardiographic data were comparable between patients with and without improvement. However, patients without improvement had considerably larger end systolic volumes (153 +/- 41 mL vs 133 +/- 46 mL, P =.007). The likelihood of recovery of global function decreased proportionally with the increase of end systolic volume (P <.001, R = 0.43, n = 61). Receiver operating characteristic curve analysis demonstrated that an end systolic volume > or = 140 mL had the highest sensitivity/specificity to predict the absence of global recovery.
  
  
  CONCLUSIONS
  In patients with ischemic cardiomyopathy not only the amount of dysfunctional but viable myocardium but also the extent of left ventricular remodeling determines the improvement in function following myocardial revascularization. Patients with a high end systolic volume due to left ventricular remodeling have a decreased likelihood of improvement of global function.
authors.affiliation: Thoraxcenter, Erasus Medical Center, Rotterdam, The Netherlands.
authors.forename: Arend F L
authors.initials: AF
authors.lastname: Schinkel
authors.forename: Don
authors.initials: D
authors.lastname: Poldermans
authors.forename: Vittoria
authors.initials: V
authors.lastname: Rizzello
authors.forename: Jean-Louis J
authors.initials: JL
authors.lastname: Vanoverschelde
authors.forename: Abdou
authors.initials: A
authors.lastname: Elhendy
authors.forename: Eric
authors.initials: E
authors.lastname: Boersma
authors.forename: Jos R T C
authors.initials: JR
authors.lastname: Roelandt
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
mesh_terms: D000368:Aged; D009202:Cardiomyopathies / Q000000981:diagnostic imaging / Q000503:physiopathology*; D023921:Coronary Stenosis / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D004452:Echocardiography; D025401:Echocardiography, Stress; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000503:physiopathology / Q000601:surgery; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D009204:Myocardial Revascularization; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D020257:Ventricular Remodeling / Q000502:physiology