Interrelationship between electrocardiographic left ventricular hypertrophy, QT prolongation, and ischaemic stroke: the REasons for Geographic and Racial Differences in Stroke Study.

Academic Article

Abstract

  • AIMS: To determine if the association between electrocardiographic left ventricular hypertrophy (ECG-LVH) and ischaemic stroke is partially explained by the concomitant presence of QT prolongation. METHODS AND RESULTS: A total of 24 948 (mean age = 65 ± 9.4 years; 40% black; 55% women) participants from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were included in this analysis. Electrocardiographic left ventricular hypertrophy was defined by the Sokolow-Lyon criteria. Heart rate-adjusted QT (QTa) was computed using a linear regression model. Adjudicated ischaemic stroke events were the outcome of interest. Cox regression was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between ECG-LVH and prolonged QTa, in isolation and combined, with ischaemic stroke. There were 2422 (9.7%) participants with ECG-LVH, 820 (3.3%) with prolonged QTa, and 161 (0.6%) with both. Over a median follow-up of 7.6 years, 714 (2.9%) ischaemic stroke events occurred. After adjustment for stroke risk factors and potential confounders, an increased risk of ischaemic stroke was observed among participants with ECG-LVH and prolonged QTa (HR = 1.85, 95% CI = 1.04-3.30), isolated ECG-LVH (HR = 1.40, 95% CI = 1.13-1.75), and isolated prolonged QTa (HR = 1.45, 95% CI = 1.04-2.03) compared with participants without either condition. When ECG-LVH and prolonged QTa were examined as separate variables, the risk of ischaemic stroke for each condition remained statistically significant. CONCLUSION: The combination of ECG-LVH and prolonged QT is associated with a higher risk of ischaemic stroke compared with either condition in isolation, and the stroke risk for each condition does not depend on the presence of the other.
  • Published In

  • EP-Europace  Journal
  • Keywords

  • Left ventricular hypertrophy, QT interval, Stroke, Aged, Arrhythmias, Cardiac, Electrocardiography, Female, Heart Rate, Humans, Hypertrophy, Left Ventricular, Kaplan-Meier Estimate, Linear Models, Male, Middle Aged, Proportional Hazards Models, Risk Factors, Stroke, United States
  • Digital Object Identifier (doi)

    Author List

  • O'Neal WT; Howard VJ; Kleindorfer D; Kissela B; Judd SE; McClure LA; Cushman M; Howard G; Soliman EZ
  • Start Page

  • 767
  • End Page

  • 772
  • Volume

  • 18
  • Issue

  • 5