title: A case series of chronic haemodialysis patients: mortality, sudden death, and QT interval.
abstract: OBJECTIVE
  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.
  
  
  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.
authors.affiliation: Department of Clinical Medicine and Prevention, University of Milano-Bicocca, Via Cadore 48, Monza, Italy. simonetta.genovesi@unimib.it
authors.forename: Simonetta
authors.initials: S
authors.lastname: Genovesi
authors.forename: Emanuela
authors.initials: E
authors.lastname: Rossi
authors.forename: Michela
authors.initials: M
authors.lastname: Nava
authors.forename: Hilary
authors.initials: H
authors.lastname: Riva
authors.forename: Silvia
authors.initials: S
authors.lastname: De Franceschi
authors.forename: Paolo
authors.initials: P
authors.lastname: Fabbrini
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Viganò
authors.forename: Federico
authors.initials: F
authors.lastname: Pieruzzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Stella
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Valsecchi
authors.forename: Marco
authors.initials: M
authors.lastname: Stramba-Badiale
mesh_terms: D000367:Age Factors; D000368:Aged; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D007558:Italy / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000628:therapy*; D016014:Linear Models; D008133:Long QT Syndrome / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality*; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left
keywords: Dilated cardiomyopathy; Haemodialysis; Left ventricular mass index; QTc interval; Sudden cardiac death; Total mortality