A case series of chronic haemodialysis patients: mortality, sudden death, and QT interval

AIMS: A high prevalence of prolonged QT interval duration has been observed among haemodialysis (HD) patients. The aim of this cases series was to describe the association of various risk factors with total mortality and sudden cardiac death (SCD) in this population.METHODS AND RESULTS: One hundred and twenty-two patients undergoing HD, [median: age 71.3 years [interquartile ratio (IQR) 62.9-76.6], HD duration 3.0 years (IQR 1.3-7.8) and 64.8% male], of which 37.7% with ischaemic cardiac disease, 41.8% with dilated cardiomyopathy (DC), 84.4% with hypertension, and 27.1% with diabetes, were studied. Median left ventricular ejection fraction (LVEF) was 60.0% (IQR 52-64) and left ventricular mass index (LVMI) was 147.3 g/m(2) (IQR 128.0-179.9). QT interval duration corrected for heart rate (QTc) was measured by electrocardiogram Holter recording and considered prolonged when longer than 450 ms in men and 460 ms in women. Forty-four patients (36.0%) had a prolonged QTc. Female gender (P < 0.001) and DC (P = 0.018) were associated with a longer QTc, while LVEF (P = 0.012) was inversely related. During the study period (median follow-up 3.9 years), 51 patients died (41.8%), of whom 12 died for SCD. In multivariate analysis age at recruitment [HR = 1.07, 95% confidence interval (CI): 1.03-1.11, P < 0.001], prolonged QTc (HR = 2.16, 95% CI: 1.20-3.91, P = 0.011) and presence of DC (HR = 3.75, 95% CI: 1.01-7.00, P < 0.001) were independently associated with total mortality, while only a prolonged QTc (HR = 8.33, 95% CI: 1.71-40.48, P = 0.009) and increasing LVMI (HR = 1.01, 95% CI: 1.00-1.02, P = 0.022) were associated with SCD.CONCLUSIONS: In a case series of HD patients, QTc was associated with total mortality and SCD. Further studies to test this hypothesis in a larger population are necessary.