title: Assessment of drug-induced torsade de pointes risk for hospitalized high-risk patients receiving QT-prolonging agents.
abstract: BACKGROUND
  Although risk factors for torsade de pointes (TdP) are known, identifying hospitalized patients at greatest risk for QTcP who should receive cardiac monitoring is poorly defined.
  
  
  OBJECTIVE
  Describe the prevalence of risk for TdP in patients and associations between risk factors and QTc prolongation (QTcP) at a tertiary teaching hospital.
  
  
  METHODS
  This retrospective analysis assessed physiological and pharmacological risk factors for TdP of adult patients receiving ≥1 QTc-prolonging medications (QTcMed) during hospitalization. The QTcMeds were stratified by risk for causing TdP (probable, possible, and conditional). Baseline electrocardiograms (ECGs) were assessed for QTcP associated with risk for TdP.
  
  
  RESULTS
  During a 6-month period, 12,401 (51%) hospitalizations received ≥1 QTcMed. A baseline ECG was obtained for 2381 (19%) patients. A total of 386 (16%) patients with a baseline ECG were found to have QTcP. Significant associations for QTcP were found with the following physiological risk factors: female (P = .021), left-ventricular ejection fraction <40% (P < .0001), cardiac arrest (P < .0001), and cardioversion (P = .007). Significantly more patients with QTcP (n = 209, 54%) received probable-risk QTcMeds than those without QTcP (n = 542, 27%; P < .0001). Probable-risk QTcMeds administered alone or concomitantly with other QTcMeds were more frequently associated with QTcP. No documented cases of TdP were identified.
  
  
  CONCLUSIONS
  Of the population receiving QTcMeds, only a small portion had a baseline ECG, identifying a large population at risk of QTcP without appropriate monitoring. Patients with cardiac disease receiving probable-risk QTcMeds were associated with the highest risk of QTcP and should be monitored closely.
authors.affiliation: St Luke's Health System, Houston, TX, USA.
authors.forename: Carla G M
authors.initials: CG
authors.lastname: Jardin
authors.forename: David
authors.initials: D
authors.lastname: Putney
authors.forename: Stephen
authors.initials: S
authors.lastname: Michaud
mesh_terms: D000328:Adult; D000368:Aged; D004562:Electrocardiography; D005260:Female; D006323:Heart Arrest / Q000453:epidemiology; D006760:Hospitalization; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced* / Q000453:epidemiology*; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D016171:Torsades de Pointes / Q000139:chemically induced* / Q000453:epidemiology*; D016277:Ventricular Function, Left
keywords: QTc prolongation; electrocardiogram; pharmacological risk factor; physiological risk factor; torsade de pointes