Abstract
BACKGROUND: Moderate-to-severe kidney disease increases risk for sudden cardiac death (SCD). Limited studies have evaluated how mild degrees of kidney dysfunction impact SCD risk. OBJECTIVE: The purpose of this study was to evaluate the association of albuminuria, which is one of the earliest biomarkers of kidney injury, and SCD. METHODS: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study is a prospective, population-based cohort of U.S. adults. Associations between albuminuria, which is categorized using urinary albumin-to-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and SCD were assessed independently and in combination. RESULTS: After median follow-up of 6.1 years, we identified 335 SCD events. Compared to participants with ACR <15 mg/g, those with higher levels had an elevated adjusted risk of SCD (ACR 15-30 mg/g, hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.11-2.11; ACR >30 mg/g, HR 1.56, 95% CI 1.17-2.11). In contrast, compared to the group with eGFR >90 mL/min/1.73 m(2), the adjusted risk of SCD was significantly elevated only among those with eGFR <45 mL/min/1.73 m(2) (HR 1.66, 95% CI 1.06-2.58). The subgroup with eGFR <45 mL/min/1.73 m(2) (n = 1003) comprised 3.7% of REGARDS, whereas ACR 15-30 mg/g (n = 3089 [11.3%]) and ACR >30 mg/g (n = 4040 [14.8%] were far more common. In the analysis that combined ACR and eGFR categories, albuminuria consistently identified individuals with eGFR ≥60 mLmin/1.73 m(2) who were at significantly increased SCD risk. CONCLUSION: Low levels of kidney injury as measured by ACR predict an increase in SCD risk.