The effect of predialysis fistula attempt on risk of all-cause and access-related death

Abstract

Whether the lower risk ofmortality associated with arteriovenous fistula use in hemodialysis patients is due to the avoidance of catheters or if healthier patients are simplymore likely to have fistulas placed is unknown. To provide clarification,wedetermined the proportion of access-relateddeaths in a retrospective cohort studyof patients aged ≥18 years who initiated hemodialysis between 2004 and 2012 at five Canadian dialysis programs. A total of 3168 patients initiated dialysis at the participating centers; 2300 met our inclusion criteria. Two investigators independently adjudicated cause of death using explicit criteria and determined whether a death was access-related.We observed significantly lower mortality in individuals who underwent a predialysis fistula attempt than in those without a predialysis fistula attempt in patients aged,<65 years (hazard ratio [HR], 0.49; 95%confidence interval [95%CI],0.29 to 0.82) andin the first 2 yearsof follow-upin those aged≥65 years (HR0-24 months, 0.60; 95% CI, 0.43 to 0.84; HR24+ months, 1.83; 95% CI, 1.25 to 2.67). Sudden deaths that occurred out of hospital accounted formost of the deaths, followed by deaths due to cardiovascular disease and infectious complications. We found only 2.3% of deaths to be access-related. In conclusion, predialysis fistula attemptmay associate with a lower risk ofmortality.However, the excessmortality observed inpatients treatedwith catheters does not appear to be due to direct, access-related complications but is likely the result of residual confounding, unmeasured comorbidity, or treatment selection bias.