Long Interdialytic Interval and Mortality among Patients Receiving Hemodialysis

TLDR

ESRD patients on dialysis tolerate few metabolic or volume deviations, and cardiovascular disease is highly prevalent. The study tested whether a long (2‑day) interdialytic interval increases adverse events in hemodialysis patients. Researchers compared death and cardiovascular‑related hospital admission rates on the day after the long interval versus other days in 32,065 U.S. hemodialysis patients (mean age 62.2, 24.2% dialysis ≤1 year). Event rates were significantly higher on the day after the long interval, including all‑cause mortality (22.1 vs 18.0), cardiac mortality (10.2 vs 7.5), infection mortality (2.5 vs 2.1), cardiac arrest (1.3 vs 1.0), myocardial infarction mortality (6.3 vs 4.4), MI admissions (6.3 vs 3.9), congestive heart failure (29.9 vs 16.9), stroke (4.7 vs 3.1), dysrhythmia (20.9 vs 11.0), and any cardiovascular event (44.2 vs 19.7), indicating heightened risk after the long interval.

Abstract

Patients with end-stage renal disease requiring dialysis have limited tolerance of metabolic and volume-related deviations from normal ranges; in addition, the prevalence of cardiovascular disease is high among such patients. Given these problems, we hypothesized that a long interdialytic interval is associated with adverse events in patients receiving hemodialysis.We studied 32,065 participants in the End-Stage Renal Disease Clinical Performance Measures Project, a nationally representative sample of U.S. patients receiving hemodialysis three times weekly, at the end of calendar years 2004 through 2007. We compared rates of death and cardiovascular-related hospital admissions on the day after the long (2-day) interdialytic interval with rates on other days.The mean age of the cohort was 62.2 years; 24.2% of the patients had been receiving dialysis treatment for 1 year or less. Over a mean follow-up interval of 2.2 years, the following event rates were higher on the day after the long interval than on other days: all-cause mortality (22.1 vs. 18.0 deaths per 100 person-years, P<0.001), mortality from cardiac causes (10.2 vs. 7.5, P<0.001), infection-related mortality (2.5 vs. 2.1, P = 0.007), mortality from cardiac arrest (1.3 vs. 1.0, P = 0.004), mortality from myocardial infarction (6.3 vs. 4.4, P<0.001), and admissions for myocardial infarction (6.3 vs. 3.9, P<0.001), congestive heart failure (29.9 vs. 16.9, P<0.001), stroke (4.7 vs. 3.1, P<0.001), dysrhythmia (20.9 vs. 11.0, P<0.001), and any cardiovascular event (44.2 vs. 19.7, P<0.001).The long (2-day) interdialytic interval is a time of heightened risk among patients receiving hemodialysis. (Funded by the National Institutes of Health.).