Modifiable practices associated with sudden death among hemodialysis patients in the dialysis outcomes and practice patterns study

Abstract

Background and objectives Sudden death is common in hemodialysis patients, but whether modifiable practices affect the risk of sudden death remains unclear. Design, setting, participants, & measurements This study analyzed 37,765 participants in 12 countries in the Dialysis Outcomes and Practice Patterns Study to explore the association of the following practices with sudden death (due to cardiac arrhythmia, cardiac arrest, and/or hyperkalemia): treatment time [TT] <210 minutes, Kt/V <1.2, ultrafiltration volume >5.7% of postdialysis weight, low dialysate potassium [K D <3]), and prescription ofQwave/Twave interval-prolonging drugs. Cox regressionwas used to estimate effects onmortality, adjusting for potential confounders. An instrumental variable approach was used to further control for unmeasured patient-level confounding. Results Therewere 9046 deaths, 26%ofwhich were sudden (crudemortality rate, 15.3/100 patient-years; median follow-up, 1.59 years). Associations with sudden death included hazard ratios of 1.13 for short TT, 1.15 for large ultrafiltration volume, and 1.10 for low Kt/V. Compared with K D ≥3 mEq/L, the sudden death rate was higher forK D≤1.5 andK D=2-2.5mEq/L. The instrumental variable approach yielded generally consistent findings. The sudden death rate was elevated for patients taking amiodarone, but not other Q wave/T wave interval-prolonging drugs. Conclusions This study identified modifiable dialysis practices associated with higher risk of sudden death, including short TT, large ultrafiltration volume, and low K D. Because K D <3 mEq/L is common and easy to change, K D tailoring may prevent some sudden deaths. This hypothesis merits testing in clinical trials. © 2012 by the American Society of Nephrology.