Sudden cardiac death in dialysis: do current guidelines for implantable cardioverter defibrillator therapy apply to patients with end-stage kidney disease?

Efficacy of Implantable Cardioverter-defibrillators for Secondary Prevention of Sudden Cardiac Death in Patients with End-stage Renal Disease

End-stage renal disease (ESRD) constitutes a major burden on the health-care system in the United States, with more than 300,000 patients nationwide being treated with renal replacement therapy. Very few studies to date have evaluated the benefit of implantable cardioverter-defibrillator (ICD) implantation for secondary prevention in patients with ESRD. In this study, we evaluated the efficacy of secondary-prevention ICDs in reducing all-cause mortality in patients on dialysis using the United States Renal Data System (USRDS) database. We queried the USRDS for relevant data between 2004 and 2010. Patients with diagnoses of ventricular fibrillation (VF), ventricular tachycardia (VT), or sudden cardiac arrest (SCA) were included in the study. Patients were excluded from the analysis if they were younger than 18 years; had missing age, sex, or race/ethnicity information; had experienced myocardial infarction; or had an ICD in situ at the time of VF, VT, or SCA diagnosis. The primary endpoint of this study was to determine the efficacy of secondary-prevention ICDs in reducing all-cause mortality in patients on dialysis. A total of 1,442 patients (3.4%) with ESRD had ICD insertion. Patients who received an ICD were predominantly younger, white males with lower Charlson Comorbidity Index and with fewer cardiovascular events. Survival at two years was 53% among those with an ICD relative to 27% among those without an ICD. In this study, we observed a substantial decrease in mortality in patients receiving an ICD for secondary prevention when compared with a cohort of similar patients with a history of VF, VT, or SCA.

Cardiovascular Outcomes in Patients on Hemodialysis following Drug-Eluting versus Bare-Metal Coronary Stents

Aim

This study sought to compare short- and long-term outcomes of drug-eluting stents (DESs) versus bare-metal stents (BMSs) implantation in patients with end-stage renal disease on hemodialysis (ESRD-HD) undergoing percutaneous coronary intervention (PCI).

Methods

Adult patients with ESRD-HD who underwent PCI at all nonfederal hospitals in Massachusetts between July 1, 2003, and September 30, 2007, were stratified based on the stent type placed at index hospitalization: DES or BMS. The primary outcome compared was a composite of all-cause death, myocardial infarction (MI), congestive heart failure (CHF), target vessel revascularization (TVR), and stroke at 30 days and one year.

Results

HD patients had a high mortality (31%) and were more likely to receive a DES than a BMS (77% versus 23%). Propensity score analysis of 2 : 1 matched DES (268) versus BMS (134) patients demonstrated the DES group to more likely have proximal LAD disease and a history of prior PCI. Conditional logistic regression analysis demonstrated no significant difference in the composite cardiovascular endpoint measured at 30 days (hazard ratio (HR) 1.09; 95% confidence interval (CI) 0.61–1.94) and one year (HR 1.03; 95% CI 0.68–1.57).

Conclusions

There were no significant differences in 30-day or 1-year major cardiovascular outcomes in HD patients undergoing PCI using the DES compared to the BMS in this high-mortality patient cohort.

A meta-analysis of mortality in end-stage renal disease patients receiving implantable cardioverter defibrillators (ICDs)

Data on the effectiveness of implantable implantable cardioverter defibrillators (ICDs) with respect to reducing mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) are lacking. The purpose of this meta-analysis was to compare the mortality of patients with ESRD who have received and not received an ICD. A search was conducted on January 31, 2013 of Medline, Cochrane, EMBASE, and Google Scholar. Studies were selected for inclusion based on the following criteria. 1) Randomized controlled trial. 2) ESRD patients with heart failure. 3) Device therapy (ICD, CRT-defibrillator [CRT-D]) used to treat heart failure. 4) Primary outcome is survival analysis. 5) Retrospective study if survival analysis was performed. The primary outcome was overall survival (OS), and the secondary outcome was 2-year survival. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated, and a χ2-based test of homogeneity was performed. Three studies were included in the analysis. The combined OR for OS was 2.245 (95% CI 1.871 to 2.685, P<0.001), indicating that patients with an ICD had a significantly higher OS than those without an ICD. The combined OR for 2-year survival was 2.312 (95% CI 1.921 to 2.784, P<0.001), indicating that patients with an ICD had a significantly higher 2-year survival rate than those without an ICD. The use of ICD in patients with ESRD is associated with an increase in the OS and the 2-year survival rate.

Major arrhythmic events and T wave morphology descriptors in hemodialyzed patients

BACKGROUND

Sudden cardiac death is common in patients receiving regular hemodialysis (HD). We recently demonstrated that selected repolarization descriptors calculated from electrocardiographic monitoring during HD demonstrate intra-subject stability. In this study we followed up the initial cohort for major arrhythmic events (MAE).

METHODS

Holter electrocardiograms (ECGs) were recorded during dialysis in 81 HD patients and repeated 5 times at 2 week intervals. The QRS-to-T angle (TCRT), the principal component analysis (PCA) ratio and the T wave morphology dispersion (TMD) were calculated in overlapping 10 second ECG segments and averaged overall recordings in each patient. Patients were followed up for MAE and non-arrhythmic mortality.

RESULTS

During 18 ± 3 months, 3 patients experienced MAE. Compared to others, MAE patients exhibited extreme TCRT and TMD values and minimal intradialytic changes.

CONCLUSION

The prognostic value of repolarization descriptors from intradialytic monitoring should be assessed prospectively.