ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO0890

Associations of Serum and Dialysate Potassium Concentrations with Incident Atrial Fibrillation in Older US Persons Initiating Hemodialysis for Kidney Failure

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis

Authors

  • Hu, Austin, Stanford University School of Medicine, Stanford, California, United States
  • Liu, Sai, Stanford University School of Medicine, Stanford, California, United States
  • Montez-Rath, Maria E., Stanford University School of Medicine, Stanford, California, United States
  • Khairallah, Pascale, Baylor College of Medicine, Houston, Texas, United States
  • Niu, Jingbo, Baylor College of Medicine, Houston, Texas, United States
  • Chang, Tara I., Stanford University School of Medicine, Stanford, California, United States
  • Winkelmayer, Wolfgang C., Baylor College of Medicine, Houston, Texas, United States
Background

Atrial fibrillation (AF) is the most common arrhythmia and affects more than a third of U.S. patients with kidney failure on hemodialysis (HD). Hyperkalemia is a common concern in the HD population and been associated with higher mortality, especially sudden death. However, little is known about the associations of serum potassium (S-K+) and prescribed dialysate potassium (D-K+) concentrations with incident AF in persons on HD.

Methods

We used health records data of a large dialysis provider merged with the US Renal Data System (2006-11). We identified persons aged 67+ when initiating HD who had 2+ years of prior Medicare coverage and not been diagnosed with AF by day 120 after start of HD. Subsequent 30 day periods were created during which S-K+ measurements were averaged; the most recent D-K+ in the preceding 30 day window was also recorded. Demographic, comorbidity, and health utilization variables were defined as were other laboratory/biometric characteristics. The outcome, newly-diagnosed AF during the subsequent 30 days, was recorded from claims. This process was repeated after frameshifting all measurements by +30 day increments. Cox regression was used to estimate hazard ratios.

Results

We studied 15,190 persons on HD without prior AF diagnosis; average age was 76 yrs, 49% were male; 69% were white, 26% black, and 8% Hispanic. At baseline, 7183 persons had a S-K+ ≥4.5 and 6988 <4.5 mEq/L. With the exception of race and ethnicity, all other characteristics, including D-K+, which was 2 mEq/L in 52% and 3 mEq/L in 34%, were balanced between groups. During a mean follow-up of 527 days the overall incidence of AF was 13/100 person-years. Modeling S-K+ as squared-term variable fit the data best. After multivariable adjustment, AF was associated with lower, but not with higher S-K+ concentrations unless extreme values >6.5 mEq/L were reached. D-K+ of 3 mEq/L, vs. 2 mEq/L, was associated with 14% (95%CI, 5-24%) lower adjusted rates of AF. No interaction between S-K+ and D-K+ was found (P=0.34).

Conclusion

Hypokalemia was strongly and independently associated with incident AF whereas hyperkalemia was not. However, choice of D-K+ of 2 mEq/L vs. 3 mEqu/L did associate with higher AF rates, independent of S-K+ and other measured characteristics.

Funding

  • NIDDK Support