1300Sudden cardiac death in patients with end stage renal disease on hemodialysis and the serial change of ECG. Multicenter prospective study

Abstract

Background: Hemodialyzed patients with end-stage renal disease (ESRD) have a higher rate of sudden cardiac death (SCD) than the general population. Characteristic changes on an electrocardiogram (ECG) are associated with ventricular arrhythmias that can cause SCD. Objective: To analyze serial changes on an ECG in patients with ESRD on hemodialysis (HD) to determine predisposing factors of SCD. Methods: We enrolled 682 patients who underwent HD at three general hospitals in Korea. Twelve-lead electrocardiography was performed at the initial HD. Regular electrocardiographic monitoring was performed before HD. All patients were followed up, and the cause of death was evaluated at an outpatient clinic or by telephone. Characteristics of the ECG (the QTc interval and dispersion, and QT peak-to-end interval [QTpe-end] of each lead) were measured; their associations with SCD were analyzed. Unexpected natural death was defined as death due to a cardiac cause within 1 hour from symptom onset in the absence of prior fatal condition. Results: Of 682 patients (53% men; mean age, 61.1±14.1 years), 293 (73% men, 69.5±14.1 years) died during a mean of 47.1±19.5 months, with 37 (12.6%) dying of SCD. Other causes of death were cardiovascular death (29.3%) infection (38.6%), cancer (10.6%), intracerebral hemorrhage (8.5%), and other bleeding (5.1%). Compared to non-SCD patients, characteristics of those with SCD were an older age (68.7±12.1 vs. 60.4±14.1 years, p<0.001) and higher male ratio (69.4 vs. 50.2%, p=0.023). Patients with diabetes (86.2 vs. 62.2%, p=0.002) were predominant among those with SCD. The decrease in ejection fraction was prominent in patients with SCD (56.3±13.3 to 49.9±11.1%) compared to non-SCD patients (58.4±11.1 to 55.2±12.3%). In serial ECG analysis, SCD patients had a higher new onset left bundle branch block (8.3 vs. 0%, p<0.001), increased QTc dispersion (78.9±51.4 vs. 62.1±23.1 ms, p=0.002), and decreased QTpe-end (V2: 4 vs. 5, p<0.05) than non- SCD patients. There were no differences in other ECG parameters between the groups. Conclusions: HD affects cardiac electrophysiology by prolonging QTc dispersion and decreasing QTpe-end. Changes on ECGs that represent ventricular electrophysiology may predict SCD in patients with ESRD on HD.