title: Regression of collateral function after recanalization of chronic total coronary occlusions: a serial assessment by intracoronary pressure and Doppler recordings.
abstract: BACKGROUND
  Collaterals can maintain myocardial function or preserve viability in chronic total coronary occlusions (CTOs). It is unknown whether and to what extent collaterals regress after successful recanalization of a CTO.
  
  
  RESULTS
  In 103 patients with successful recanalization of a CTO collateral function was assessed by intracoronary Doppler and pressure recordings before and after recanalization, and again after 5.0+/-1.3 months. Doppler (CFI) and pressure-derived collateral function indexes (CPI) and collateral (RColl) and peripheral resistance indexes (RP) were calculated. In 10 patients with reocclusion, all without myocardial infarction during follow-up, collateral function had reached a similar level as before the first recanalization. In the other 93 patients with or without restenosis, collateral function was attenuated during follow-up. CPI had decreased by 23% immediately after recanalization (P<0.001) and decreased further by another 23% at follow-up (P<0.001). The RColl increased immediately after recanalization by 82% (P<0.001) and by a further 273% at follow-up (P<0.001). In contrast, RP increased only by 22% after recanalization (P<0.001) and by an additional 12% at follow-up (P<0.05). The initial size of the collaterals but not the incidence of a restenosis influenced the collateral regression. Only 18% of patients at follow-up had collaterals with a CPI >0.30, presumably sufficient to prevent ischemia during acute occlusion.
  
  
  CONCLUSIONS
  Collateral function regresses during long-term follow-up, especially in collaterals with a small diameter. In the majority of patients, collaterals are not readily recruitable in the case of acute occlusion. However, collaterals have the potential to recover in the case of chronic reocclusion.
authors: Clinic for Internal Medicine I, Friedrich-Schiller-University, Jena, Germany. gerald.werner@med.uni-jena.de
authors: Gerald S
authors: GS
authors: Werner
authors: Ulf
authors: U
authors: Emig
authors: Oliver
authors: O
authors: Mutschke
authors: Gero
authors: G
authors: Schwarz
authors: Philipp
authors: P
authors: Bahrmann
authors: Hans R
authors: HR
authors: Figulla
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000925:Anticoagulants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D000077144:Clopidogrel; D003097:Collateral Circulation; D003131:Combined Modality Therapy; D017023:Coronary Angiography; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin; D011312:Pressure; D012008:Recurrence; D013318:Stroke Volume; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D014463:Ultrasonography
chemical_list: D000925:Anticoagulants; D006493:Heparin; D000077144:Clopidogrel; D005996:Nitroglycerin; D013988:Ticlopidine; D001241:Aspirin