Trends in Hyperkalemia‐Related Sudden Cardiac Death Among Older Adults in the United States, 1999–2020

BACKGROUND: Hyperkalemia is a potentially life-threatening electrolyte disturbance, particularly in older adults with comorbidities. Hyperkalemia can trigger fatal arrhythmias and contribute to sudden cardiac death (SCD). However, national trends in hyperkalemia-related SCD remain poorly defined, especially in the aging US population. METHODS: We conducted a cross-sectional analysis using CDC WONDER mortality data from 1999 to 2020. Deaths were identified using ICD-10 codes for SCD (I46.1, I46.9) as the underlying cause and hyperkalemia (E87.5) as a contributing cause. Age-adjusted mortality rates (AAMRs) were calculated using the 2000 US standard population. Joinpoint regression was used to assess temporal trends and estimate annual percentage changes (APCs). Analyses were stratified by sex, age, race/ethnicity, region, urbanization, and state. RESULTS: Between 1999 and 2020, 36 607 hyperkalemia-related SCD deaths were recorded. The national AAMR more than doubled, from 0.65 to 1.32 per 100 000. Mortality was stable from 1999 to 2009 (APC -1.09%, p = 0.0566) but rose significantly from 2010 to 2020 (APC +5.02%, p < 0.0001). Males, Black individuals, and residents of the South and Midwest had the highest AAMRs and steepest increases. Rural areas consistently showed higher mortality than urban ones. Though most deaths occurred in older adults, significant increases were observed in younger adults (25-44 years) in the last decade. Nevada, Rhode Island, and California had the highest state-level rates. CONCLUSION: Hyperkalemia-related SCD mortality has risen substantially, with marked disparities by sex, race, geography, and age. These trends underscore the need for improved potassium monitoring, risk stratification, and equitable healthcare access to reduce preventable deaths.