title: An analysis of IN.PACT DEEP randomized trial on the limitations of the societal guidelines-recommended hemodynamic parameters to diagnose critical limb ischemia.
abstract: OBJECTIVE
  Recent small single-center data indicate that the current hemodynamic parameters used to diagnose critical limb ischemia are insensitive. We investigated the validity of the societal guidelines-recommended hemodynamic parameters against core laboratory-adjudicated angiographic data from the multicenter IN.PACT DEEP (RandomIzed AmPhirion DEEP DEB vs StAndard PTA for the treatment of below the knee Critical limb ischemia) Trial.
  
  
  METHODS
  Of the 358 patients in the IN.PACT DEEP Trial to assess drug-eluting balloon vs standard balloon angioplasty for infrapopliteal disease, 237 had isolated infrapopliteal disease with an available ankle-brachial index (ABI), and only 40 of the latter had available toe pressure measurements. The associations between ABI, ankle pressure, and toe pressure with tibial runoff, Rutherford category, and plantar arch were examined according to the cutoff points recommended by the societal guidelines. Abnormal tibial runoff was defined as severely stenotic (≥70%) or occluded and scored as one-, two-, or three-vessel disease. A stenotic or occluded plantar arch was considered abnormal.
  
  
  RESULTS
  Only 14 of 237 patients (6%) had an ABI <0.4. Abnormal ankle pressure, defined as <50 mm Hg if Rutherford category 4 and <70 mm Hg if Rutherford category 5 or 6, was found only in 37 patients (16%). Abnormal toe pressure, defined as <30 mm Hg if Rutherford category 4 and <50 mm Hg if Rutherford category 5 or 6, was found in 24 of 40 patients (60%) with available measurements. Importantly, 29% of these 24 patients had an ABI within normal reference ranges. A univariate multinomial logistic regression found no association between the above hemodynamic parameters and the number of diseased infrapopliteal vessels. However, there was a significant paradoxic association where patients with Rutherford category 6 had higher ABI and ankle pressure than those with Rutherford category 5. Similarly, there was no association between ABI and pedal arch patency.
  
  
  CONCLUSIONS
  The current recommended hemodynamic parameters fail to identify a significant portion of patients with lower extremity ulcers and angiographically proven severe disease. Toe pressure has better sensitivity and should be considered in all patients with critical limb ischemia.
authors: Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio. Electronic address: shishem@ccf.org.
authors: Mehdi H
authors: MH
authors: Shishehbor
authors: Department of Hospital Medicine, Medicine Institute, Cleveland Clinic, Cleveland, Ohio.
authors: Tarek A
authors: TA
authors: Hammad
authors: Department of Angiology, Universitäts Herzzentrum Freiburg Bad Krozingen, Bad Krozingen, Germany.
authors: Thomas
authors: T
authors: Zeller
authors: Swiss Cardiovascular Center, Division of Angiology, University Hospital, Inselspital, Bern, Switzerland.
authors: Iris
authors: I
authors: Baumgartner
authors: Department of Angiology and Cardiology, Center of Vascular Medicine, Park Hospital Leipzig, Leipzig, Germany.
authors: Dierk
authors: D
authors: Scheinert
authors: Department of Vascular and Endovascular Medicine, Prairie Heart Institute at St John's Hospital, Springfield, Ill.
authors: Krishna J
authors: KJ
authors: Rocha-Singh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000592:standards*; D055109:Ankle Brachial Index / Q000592:standards*; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000592:standards*; D016009:Chi-Square Distribution; D016638:Critical Illness; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007511:Ischemia / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D016015:Logistic Models; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014654:Vascular Patency