title: The renal arterial resistance index and renal allograft survival.
abstract: BACKGROUND
  Most renal transplants fail because of chronic allograft nephropathy or because the recipient dies, but no reliable factor predicting long-term outcome has been identified. We tested whether a renal arterial resistance index of less than 80 was predictive of long-term allograft survival.
  
  
  METHODS
  The renal segmental arterial resistance index (the percentage reduction of the end-diastolic flow as compared with the systolic flow) was measured by Doppler ultrasonography in 601 patients at least three months after transplantation between August 1997 and November 1998. All patients were followed for three or more years. The combined end point was a decrease of 50 percent or more in the creatinine clearance rate, allograft failure (indicated by the need for dialysis), or death.
  
  
  RESULTS
  A total of 122 patients (20 percent) had a resistance index of 80 or higher. Eighty-four of these patients (69 percent) had a decrease of 50 percent or more in creatinine clearance, as compared with 56 of the 479 patients with a resistance index of less than 80 (12 percent); 57 patients with a higher resistance index (47 percent) required dialysis, as compared with 43 patients with a lower resistance index (9 percent); and 36 patients with a higher resistance index (30 percent) died, as compared with 33 patients with a lower resistance index (7 percent) (P<0.001 for all comparisons). A total of 107 patients with a higher resistance index (88 percent) reached the combined end point, as compared with 83 of those with a lower resistance index (17 percent, P<0.001). The multivariate relative risk of graft loss among patients with a higher resistance index was 9.1 (95 percent confidence interval, 6.6 to 12.7). Proteinuria (protein excretion, 1 g per day or more), symptomatic cytomegalovirus infection, and a creatinine clearance rate of less than 30 ml per minute per 1.73 m2 of body-surface area after transplantation also increased the risk.
  
  
  CONCLUSIONS
  A renal arterial resistance index of 80 or higher measured at least three months after transplantation is associated with poor subsequent allograft performance and death.
authors.affiliation: Department of Nephrology, Hannover Medical School, Hannover, Germany. radermacher.joerg@mh-hannover.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Radermacher
authors.forename: Michael
authors.initials: M
authors.lastname: Mengel
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ellis
authors.forename: Stephan
authors.initials: S
authors.lastname: Stuht
authors.forename: Markus
authors.initials: M
authors.lastname: Hiss
authors.forename: Anke
authors.initials: A
authors.lastname: Schwarz
authors.forename: Ute
authors.initials: U
authors.lastname: Eisenberger
authors.forename: Michael
authors.initials: M
authors.lastname: Burg
authors.forename: Friedrich C
authors.initials: FC
authors.lastname: Luft
authors.forename: Wilfried
authors.initials: W
authors.lastname: Gwinner
authors.forename: Hermann
authors.initials: H
authors.lastname: Haller
mesh_terms: D001706:Biopsy; D003404:Creatinine / Q000378:metabolism; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000473:pathology; D007676:Kidney Failure, Chronic / Q000209:etiology; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000401:mortality / Q000473:pathology / Q000502:physiology*; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D012079:Renal Circulation / Q000502:physiology*; D016019:Survival Analysis; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance
chemical_list: D003404:Creatinine