Sudden death and associated factors in a historical cohort of chronic haemodialysis patients

Background In haemodialysis patients, deaths due to cardiovascular causes constitute a large proportion of total mortality and sudden cardiac deaths account for approximately 22% of all deaths. The aim of this study was to evaluate the incidence of sudden cardiac death and associated risk factors in a cohort of haemodialysis patients. Methods and results The 3-year cumulative incidence of death in a cohort of 476 patients on chronic haemodialysis treatment was 34.3% (SE 2.3). Sudden death had a 6.9% (SE 1.2) cumulative incidence, with 32 events representing 19.2% of all deaths, while cardiovascular not sudden death and noncardiovascular death accounted for a 3-year cumulative incidence of 7.3% (SE 1.2) and 20.1% (SE 1.9), respectively. According to Cox multivariate analysis, significant risk factors for sudden death were the presence of atrial fibrillation, diabetes mellitus, predialytic hyperkalaemia, haemodialysis mode and C-reactive protein level, which were associated with a 2.9 (CI(95%) 1.3-6.4), 3.0 (CI(95%) 1.3-7.2), 2.7 (CI(95%) 1.3-5.8), 4.5 (CI(95%) 1.3-15.5) and 3.3 (CI(95%) 1.2-8.8)-fold increase in the risk of sudden death, respectively. Sudden death was significantly more frequent during the first 24 h of the first short interdialytic interval and during the last 24 h of the long interval, i.e. immediately before and immediately after the first weekly haemodialysis session (P = 0.02). Conclusions Our data show that the incidence of sudden death in haemodialysis patients is high and that atrial fibrillation, diabetes, hyperkalaemia, haemodialysis mode and C-reactive protein play an important role in developing fatal arrhythmia. Further studies will be necessary to define which interventions could be helpful in reducing this cause of mortality.