title: Predictors of improvement in left ventricular function after percutaneous revascularization of occluded coronary arteries: a report from the Total Occlusion Study of Canada (TOSCA).
abstract: BACKGROUND
  The Total Occlusion Study of Canada (TOSCA) is a multicenter, randomized trial evaluating the effect of stenting with > =1 heparin-coated stent on long-term patency after percutaneous coronary intervention by balloon angioplasty of occluded coronary arteries. The purpose of the current study was to compare the effect of stenting and balloon angioplasty on global left ventricular ejection fraction (LVEF) and regional wall motion and to examine what clinical and angiographic factors may have an effect on left ventricular function in this setting.
  
  
  RESULTS
  Analysis at the core angiographic laboratory of paired baseline and follow-up left ventricular angiograms, as well as target vessel patency, was possible in 244 of 410 cases. An improvement in LVEF was observed in the entire group (59.4% +/- 11% to 61.0% +/- 11%, P =.003). The LVEF change was +1.84 +/- 7.54 in the stent group (P =.009) and 1.28 +/- 8.16 in the percutaneous transluminal coronary angioplasty group (P =.085). There was no significant intergroup difference. Patients with duration of occlusion < or =6 weeks had an improvement in LVEF (+2.98 +/- 8.68, P =.0006), whereas those with an occlusion duration of > 6 weeks had no improvement (+0.48 +/- 7.01, P not significant). Multivariate analysis revealed baseline LVEF <60%, duration of occlusion < or =6 weeks, and Canadian Cardiology Society angina class I or II to be independent predictors of improvement in LVEF.
  
  
  CONCLUSIONS
  The restoration of coronary patency of nonacute occluded coronary arteries is associated with a small but significant improvement in regional and global left ventricular function, especially in patients with recent occlusions and depressed left ventricular function. In spite of significant effect on long-term patency, stenting of nonacute coronary occlusions does not result in significantly better left ventricular function compared with balloon angioplasty in this setting.
authors.affiliation: University Health Network, Toronto, Ontario, Canada. vlad.dzavik@uhn.on.ca
authors.forename: V
authors.initials: V
authors.lastname: Dzavik
authors.forename: R G
authors.initials: RG
authors.lastname: Carere
authors.forename: G B
authors.initials: GB
authors.lastname: Mancini
authors.forename: E A
authors.initials: EA
authors.lastname: Cohen
authors.forename: D
authors.initials: D
authors.lastname: Catellier
authors.forename: T E
authors.initials: TE
authors.lastname: Anderson
authors.forename: G
authors.initials: G
authors.lastname: Barbeau
authors.forename: C
authors.initials: C
authors.lastname: Lazzam
authors.forename: L M
authors.initials: LM
authors.lastname: Title
authors.forename: P B
authors.initials: PB
authors.lastname: Berger
authors.forename: M
authors.initials: M
authors.lastname: Labinaz
authors.forename: K K
authors.initials: KK
authors.lastname: Teo
authors.forename: C E
authors.initials: CE
authors.lastname: Buller
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000627:therapeutic use; D001955:British Columbia; D017023:Coronary Angiography; D003327:Coronary Disease / Q000628:therapy*; D005260:Female; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015607:Stents; D016896:Treatment Outcome; D016277:Ventricular Function, Left
chemical_list: D000925:Anticoagulants; D006493:Heparin