Risk of Mortality Associated With QT and JT Intervals at Different Levels of QRS Duration (from the Third National Health and Nutrition Examination Survey)

• Type of Material: Article
• Authors: Muhammad A. Zulqarnain, Wake Forest School of Medicine; Waqas T. Qureshi, Wake Forest School of Medicine; Wesley T. O'Neal, Wake Forest School of Medicine; Amit Shah, Emory University; Elsayed Z. Soliman, Wake Forest School of Medicine
• Language: English
• Date: 2015-07-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2015 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1016/j.amjcard.2015.03.038
• Title of Journal or Parent Work: American Journal of Cardiology
• ISSN: 0002-9149
• Volume: 116
• Issue: 1
• Start Page: 74
• End Page: 78
• Grant/Funding Information: AJS was supported, in part, by the National Center for Advancing Translational Sciences of the National institutes of Health under Award Number UL1TR000454 and KL2TR000455.; WTQ is funded by Ruth L. Kirschstein NRSA Institutional Training Grant 5T32HL076132-10.
• Keywords: JT interval; NHANES; mortality; QT interval
• Research Categories: Health Sciences, Epidemiology; Health Sciences, General

Abstract

QT prolongation in the setting of QRS>120 ms is believed to be triggered by prolonged depolarization rather than repolarization. Hence, JT interval is suggested as an alternative to QT interval when QRS duration is prolonged. It is unclear, however, if JT and QT intervals portend similar risk of mortality for different durations of QRS. We examined the association between QT and JT, separately, with all-cause mortality across different levels of QRS duration in 8,025 participants (60±13 years, 41% white, and 54% women) from the Third National Health and Nutrition Examination Survey. At baseline (1986–1994), 486 (6%) participants had QRS duration≥120 ms. During a follow-up of up to 18 years, 3,045 (38%) deaths occurred. There were significant non-linear relationships of QT and JT intervals with mortality (p <0.001). Hence, QT and JT were categorized as prolonged (>95th percentile), shortened (<5th percentile) and normal (reference group). In multivariate adjusted Cox regression models, prolonged JT [HR (95% CI): 4.75, (1.86, 12.11)] was associated with increased risk of mortality more than prolonged QT [HR (95%CI):1.50 (1.03, 2.17)] in participants with QRS ≥120 ms (Interaction p=0.02). In participants with QRS duration <120ms, prolonged QT and JT were equally predictive of all-cause mortality [HR (95%CI): 1.27(1.06, 1.54)] and [1.31 (1.10, 1.55)], respectively. Similar patterns were observed with shortened QT and JT intervals. In conclusion, although both QT and JT intervals are predictive of mortality, JT is more predictive in the setting of QRS duration>120 ms supporting the use of JT interval in individuals with prolonged QRS.