title: Impact of early kidney resistance index on kidney graft and patient survival during a 5-year follow-up.
abstract: BACKGROUND
  Resistance index (RI) measured by Doppler sonography during the early post-transplant period reflects interstitial oedema within the transplanted kidney. We have prospectively analysed the relationship between RI measured shortly after kidney transplantation (KTx), patient and graft survival, as well as kidney graft function during a 5-year follow-up.
  
  
  METHODS
  RI was measured at the second to fourth day after KTx in 364 consecutive patients, who were divided into tertiles, according to baseline RI value (Group 1: RI < 0.73, Group 2: RI between 0.73 and 0.85 and Group 3: RI > 0.85). The kidney graft function [estimated glomerular filtration rate (eGFR)] during the follow-up period was calculated according to the Modification of Diet in Renal Disease formula.
  
  
  RESULTS
  During the 5-year follow-up period, 23 patients died (2.6 versus 6.5 versus 9.6% in RI tertiles, respectively) and 59 lost their kidney graft (12.1 versus 17.7 versus 18.4%, respectively). Survival analyses showed that the effect of RI was significant for a combined outcome [graft loss or death; hazard ratio (HR) = 10.88] and in relation to death, it was of borderline significance (HR = 45.3, P = 0.09). The effect of delayed graft function (DGF) was only significant on graft loss (HR = 1.73). eGFR in the highest tertile was lower than in the lowest tertile during the entire follow-up period.
  
  
  CONCLUSIONS
  High RI values measured in segmental arteries in the very early post-transplant period predict worse kidney graft function and increased risk of all-cause graft loss, including patient death in the 5-year follow-up period. (ii) The predictive value of RI is not completely independent from the adverse influence of DGF on the premature graft loss.
authors.affiliation: Department of Nephrology, Endocrinology and Metabolic Diseases, Medical University of Silesia, Katowice, Poland.
authors.forename: Aureliusz
authors.initials: A
authors.lastname: Kolonko
authors.forename: Jerzy
authors.initials: J
authors.lastname: Chudek
authors.forename: Jan E
authors.initials: JE
authors.lastname: Zejda
authors.forename: Andrzej
authors.initials: A
authors.lastname: Wiecek
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000401:mortality*; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015996:Survival Rate; D013997:Time Factors; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance / Q000502:physiology*