Mortality, sudden death and indication for cardioverter defibrillator implantation in a dialysis population.
BACKGROUND
The incidence of sudden death among dialysis patients is high, but end stage renal disease was an exclusion criterion in the trials that demonstrated the benefit of implantable cardioverter defibrillator (ICD) for sudden death prevention.


METHODS
Dialysis patients alive on January 2010 or starting dialysis between January 2010 and January 2013 were enrolled and retrospectively evaluated. Patients were divided into three groups: No-Indication, Indication-With ICD and Indication-Without ICD. Cox and Fine and Gray regression models were used to estimate the total and cause-specific (sudden or non-sudden) mortality hazard ratio (HR, HR(cpRisk)), respectively. Survival was defined as the time from start of dialysis to the time of death.


RESULTS
154/2072 patients (7.4%) had indication for ICD implantation and 52 (33.8%) of them received the device; 688 (33.2%) deaths were recorded. Mortality was different among groups [Indication-With ICD vs No-Indication: HR 1.59 (95% CI 1.06-2.38) and Indication-Without ICD vs No-Indication: HR 2.67 (95% CI 2.09-3.39, p < 0.001)]. 84/688 (12.2%) were sudden deaths. The cumulative incidence of sudden death was higher in patients with ICD indication [Indication-With ICD vs No-Indication HR(cpRisk) 3.21 (95% CI 1.38-7.40) and Indication-Without ICD vs No-Indication: HR(cpRisk) 4.19 (95% CI 2.38-7.39), p < 0.001], but also No-Indication patients showed a high rate of sudden death [8.5% (95% CI.6.5-10.9) at 8 years of follow-up].


CONCLUSIONS
Dialysis patients with ICD indication had a worse survival than No-Indication subjects and the prognosis was particularly poor for the Indication-Without ICD group. Sudden death incidence was much higher than in the general population, even among No-Indication subjects.