The Incidence and Associated Factors of Sudden Death in Patients on Hemodialysis: 10-Year Outcome of the Q-Cohort Study

Aim: The incidence of sudden death and its risk factors in patients on hemodialysis remain unclear. This study aimed to clarify the incidence of sudden death and its risk factors in Japanese patients on hemodialysis. Methods: A total of 3505 patients on hemodialysis aged 18 years were followed for 10 years. Multivariate-adjusted hazard ratio (HR) with 95% confidence interval (95% CI) of each risk factor of sudden death were calculated using a Cox proportional hazards model. Results: During the 10-year follow-up, 1735 patients died, including 227 (13%) sudden deaths. The incidence rate of sudden death was 9.13 per 1000 person-years. In multivariable-adjusted Cox analysis, male sex (HR 1.67; 95% CI 1.20-2.33), age (HR 1.44; 95% CI 1.26-1.65 per 10-year higher), the presence of diabetes (HR 2.45; 95% CI 1.82-3.29), history of cardiovascular disease (HR 1.85; 95% CI 1.38-2.46), cardiothoracic ratio (HR 1.21; 95% CI 1.07-1.39 per 5% higher), serum C-reactive protein (HR 1.11; 95% CI 1.03-1.20 per 1-mg/dL higher), and serum phosphate (HR 1.15; 95% CI 1.03-1.30 per 1-mg/dL higher) were independent predictors of sudden death. A subgroup analysis stratified by sex or age showed that lower serum corrected calcium levels, not using vitamin D receptor activators in women, and a shorter dialysis session length in men or older people (>= 65 years) increased the risk for sudden death. Conclusions: This study clarified the incidence of sudden death and its specific predictors in Japanese patients on hemodialysis.