Abstract: PO0890
Associations of Serum and Dialysate Potassium Concentrations with Incident Atrial Fibrillation in Older US Persons Initiating Hemodialysis for Kidney Failure
Session Information
- Fluid, Electrolytes, and Clinical Events with Dialysis: Getting to the "Heart" of the Matter
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
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