Objectives: The study sought to assess the prognostic impact of chronic kidney disease (CKD) in patients with electrical storm (ES). 
Background: ES represents a serious life-threatening heart rhythm disorder. Especially CKD-patients are at risk to suffer from ES. However, data regarding the prognostic impact of CKD on long-term mortality in ES-patients is limited. 
Methods: All consecutive ES-patients with implantable cardioverter defibrillator (ICD) were included retrospectively from 2002 to 2016. Patients with CKD (MDRD-GFR < 60 ml/min/1.73m²) were compared to patients without CKD. The primary endpoint was all-cause mortality at 3 years. Secondary endpoints were in-hospital mortality, cardiac rehospitalization, recurrences of electrical storm (ES-R) and major adverse cardiac events (MACE) at 3 years. 
Results: A total of 70 consecutive ES patients were included. CKD was present in 43% of ES-patients with a median glomerular filtration rate (GFR) of 43.3 ml/min/1.73m². CKD was associated with increased all-cause mortality at 3 years (63% vs. 20%; p=0.001; HR=4.293; 95% CI 1.874-9.836; p=0.00) and MACE (57% vs. 30%; p=0.025; HR=3.597; 95% CI 1.679-7.708; p=0.001). In contrast, first cardiac rehospitalization (43% vs. 45%; log rank p=0.889) and ES-R (30% vs. 20%; log rank p=0.334) were not affected by CKD. Increased long-term mortality was still evident after multivariable adjustment (HR=2.397; 95% CI 1.012-5.697; p=0.047). The presence of CKD was also associated with the secondary endpoint MACE (HR= 2.520; 95% CI 1.109 – 5.727; p= 0.027 after multivariable adjustment.
Conclusion: The presence of CKD was associated with increased long-term mortality and MACE in patients presenting with ES.