Severe Kidney Dysfunction Associated With Increased Incidence of Arrhythmia

Severe Kidney Dysfunction Associated With Increased Incidence of Arrhythmia in Patients With Chronic Kidney Disease: Presented at NKF

By Deborah Brauser

NASHVILLE, Tenn -- March 30, 2009 -- Severely reduced renal function is associated with a significant increase in automatic implanted cardioverter defibrillator (AICD) shocks in patients with stage 4 and stage 5 chronic kidney disease (CKD), according to research presented at the National Kidney Foundation (NKF) 2009 Spring Clinical Meetings.

Lead investigator Marc Zelkowitz, MD, Jacobi Medical Center, Albert Einstein College of Medicine, New York, New York, presented details from his retrospective study in a poster session here on March 26.

Epidemiological studies have shown a link between kidney dysfunction and risk of cardiovascular disease, and Dr. Zelkowitz and colleagues sought to determine the association, if any, between decreasing estimated glomerular filtration rate (eGFR) in CKD and the incidence of arrhythmia by conducting a retrospective chart review.

The investigative team evaluated the charts of 235 patients aged older than 18 years, who underwent first-time placement of an AICD between January 2004 and December 2006, and had a minimum follow-up of 1 year.

The researchers examined demographic characteristics, as well as Modification of Diet in Renal Disease (MDRD) GFR using serum creatinine levels at the time of AICD implant. They also reviewed both outpatient and inpatient interrogation reports to determine the following: occurrence of any subsequent shock; antitachycardia overdrive pacing (ATP); other arrhythmias; and time to first shock.

A Chi-square test was used to analyse eGFR and a Cox regression model (adjusted for age, sex, and length of follow-up) was performed to analyse time to first shock, when applicable.

Results suggested a significant linear association between stage 4 and stage 5 CKD and the number of shock occurrences, which otherwise would have been fatal arrhythmias if not for the AICD.

An eGFR of less than 30 mL/min was significantly associated with shock occurrence (P = .048), but not with ATP or other type of arrhythmias.

The time to first shock also showed an increased hazard of eGFR at less than 30 mL/min (hazard ratio rate, 2.2; 95% confidence interval, 1.1 to 4.5; P = .03).

"Our thinking at the start [of the study] was that we're losing patients in the CKD groups before they're starting dialysis; [now] we're thinking that cardiovascular disease is probably a major component of that," said Dr. Zelkowitz.

"Eventually, for the long term, we think what needs to be done is looking into adding [AICDs] in stage 4 and stage 5 CKD patients as primary prophylaxis due to the occurrences of ventricular arrhythmias," concluded Dr. Zelkowitz. "So far, it's really only been cardiac patients who have [AICDs] placed for cardiac reasons, but maybe we should look in the future to possibly extending it to these severe CKD patients."

[Presentation title: CKD and Incidence of Arrhythmias in Patients With Internal Cardiac Defibrillators. Abstract 61]

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