title: Collateral donor artery physiology and the influence of a chronic total occlusion on fractional flow reserve.
abstract: BACKGROUND
  The presence of a concomitant chronic total coronary occlusion (CTO) and a large collateral contribution might alter the fractional flow reserve (FFR) of an interrogated vessel, rendering the FFR unreliable at predicting ischemia should the CTO vessel be revascularized and potentially affecting the decision on optimal revascularization strategy. We tested the hypothesis that donor vessel FFR would significantly change after percutaneous coronary intervention of a concomitant CTO.
  
  
  RESULTS
  In consecutive patients undergoing percutaneous coronary intervention of a CTO, coronary pressure and flow velocity were measured at baseline and hyperemia in proximal and distal segments of both nontarget vessels, before and after percutaneous coronary intervention. Hemodynamics including FFR, absolute coronary flow, and the coronary flow velocity-pressure gradient relation were calculated. After successful percutaneous coronary intervention in 34 of 46 patients, FFR in the predominant donor vessel increased from 0.782 to 0.810 (difference, 0.028 [0.012 to 0.044]; P=0.001). Mean decrease in baseline donor vessel absolute flow adjusted for rate pressure product: 177.5 to 139.9 mL/min (difference -37.6 [-62.6 to -12.6]; P=0.005), mean decrease in hyperemic flow: 306.5 to 272.9 mL/min (difference, -33.5 [-58.7 to -8.3]; P=0.011). Change in predominant donor vessel FFR correlated with angiographic (%) diameter stenosis severity (r=0.44; P=0.009) and was strongly related to stenosis severity measured by the coronary flow velocity-pressure gradient relation (r=0.69; P<0.001).
  
  
  CONCLUSIONS
  Recanalization of a CTO results in a modest increase in the FFR of the predominant collateral donor vessel associated with a reduction in coronary flow. A larger increase in FFR is associated with greater coronary stenosis severity.
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.). andrew.ladwiniec@nhs.net.
authors: Andrew
authors: A
authors: Ladwiniec
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Michael S
authors: MS
authors: Cunnington
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Jennifer
authors: J
authors: Rossington
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Adam N
authors: AN
authors: Mather
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Albert
authors: A
authors: Alahmar
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Richard M
authors: RM
authors: Oliver
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Sukhjinder S
authors: SS
authors: Nijjer
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Justin E
authors: JE
authors: Davies
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Simon
authors: S
authors: Thackray
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Farquad
authors: F
authors: Alamgir
authors: From the Department of Cardiology, Castle Hill Hospital, Kingston-upon-Hull, United Kingdom (A.L., M.S.C., J.R., A.N.M., A.A., R.M.O., S.T., F.A., A.H.); Department of Academic Cardiology, Hull York Medical School, Kingston-upon-Hull, United Kingdom (A.L., A.H.); and Imperial College London, London, United Kingdom (S.S.N., J.E.D.).
authors: Angela
authors: A
authors: Hoye
mesh_terms: D000368:Aged; D001158:Arteries / Q000502:physiology*; D002908:Chronic Disease; D003097:Collateral Circulation; D054059:Coronary Occlusion / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006940:Hyperemia / Q000175:diagnosis* / Q000209:etiology; D007511:Ischemia / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D011183:Postoperative Complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011379:Prognosis; D014019:Tissue Donors
keywords: collateral circulation; coronary artery disease; physiology; pressure