Hollie Russell1, Leonid Churilov2, Lisa Toh3, Glenn M Eastwood4, Rinaldo Bellomo5. 1. Department of Intensive Care, Austin Hospital, Heidelberg, Melbourne, Australia; Melbourne Medical School (Austin Clinical School), The University of Melbourne, Victoria, Australia. 2. Centre for Integrated Critical Care, The University of Melbourne, Victoria, Australia; Melbourne Medical School (Austin Clinical School), The University of Melbourne, Victoria, Australia. 3. Department of Intensive Care, Austin Hospital, Heidelberg, Melbourne, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia. 4. Department of Intensive Care, Austin Hospital, Heidelberg, Melbourne, Australia. 5. Department of Intensive Care, Austin Hospital, Heidelberg, Melbourne, Australia; Centre for Integrated Critical Care, The University of Melbourne, Victoria, Australia. Electronic address: rinaldo.bellomo@austin.org.au.
Abstract
PURPOSE: To study the incidence, predictors and outcomes of QTc prolongation (≥500 ms) during ICU admission. METHODS: Prospective observational study of patients admitted to a tertiary ICU during a two-month period. We obtained daily data on QTc intervals and arrhythmias from ICU monitors. We performed univariate and multivariable analyses to compare patients who did or did not experience QTc prolongation. RESULTS: Of the 257 patients, 93 (36.2%) developed ≥1 episode of QTc ≥500 ms. Such patients had higher APACHE II scores (p < .001), received more QT-prolonging medications (p = .002), and more frequently developed non-sustained (<8 beats, p = .007) and sustained ventricular tachycardia (≥8 beats; p < .001). However, after adjustment for confounders, there was no independent association between QTc duration and odds of ventricular tachyarrhythmia (OR = 0.921 [0.593-1.431], p = .715). Moreover, 98% of ventricular tachyarrhythmias resolved spontaneously. Patients with QTc prolongation had longer ICU (p < .001) and hospital length-of-stay (p = .002), and greater ICU (p = .030) and in-hospital mortality (p = .015). No patient experienced sustained Torsades de Pointes or died from ventricular arrhythmia. CONCLUSIONS: A QTc ≥500 ms likely represents a marker of illness severity modulated by several risk factors, and carries no independent association with clinically-significant ventricular tachyarrhythmias. Thus, cessation of QT-prolonging medications to prevent arrhythmias may lack clinical benefit.
PURPOSE: To study the incidence, predictors and outcomes of QTc prolongation (≥500 ms) during ICU admission. METHODS: Prospective observational study of patients admitted to a tertiary ICU during a two-month period. We obtained daily data on QTc intervals and arrhythmias from ICU monitors. We performed univariate and multivariable analyses to compare patients who did or did not experience QTc prolongation. RESULTS: Of the 257 patients, 93 (36.2%) developed ≥1 episode of QTc ≥500 ms. Such patients had higher APACHE II scores (p < .001), received more QT-prolonging medications (p = .002), and more frequently developed non-sustained (<8 beats, p = .007) and sustained ventricular tachycardia (≥8 beats; p < .001). However, after adjustment for confounders, there was no independent association between QTc duration and odds of ventricular tachyarrhythmia (OR = 0.921 [0.593-1.431], p = .715). Moreover, 98% of ventricular tachyarrhythmias resolved spontaneously. Patients with QTc prolongation had longer ICU (p < .001) and hospital length-of-stay (p = .002), and greater ICU (p = .030) and in-hospital mortality (p = .015). No patient experienced sustained Torsades de Pointes or died from ventricular arrhythmia. CONCLUSIONS: A QTc ≥500 ms likely represents a marker of illness severity modulated by several risk factors, and carries no independent association with clinically-significant ventricular tachyarrhythmias. Thus, cessation of QT-prolonging medications to prevent arrhythmias may lack clinical benefit.
Authors: Avni Thakore; James Nguyen; Simcha Pollack; Stefan Muehlbauer; Benjamin Chi; Derek Knight; Bhoomi Mehrotra; Joshua Stern; J Jane Cao; Charles Lucore; Joseph Levine Journal: EClinicalMedicine Date: 2021-08-06