Prolonged QT Interval and QT Dispersion in Individuals Infected with Human Immunodeficiency Virus (HIV)

1. Prolonged QT Interval and QT Dispersion in IndividualsInfected with Human Immunodeficiency Virus (HIV) Anne Tasaki, BS; James Taylor, BS; Dominic Chow, MD, MPH; Cecilia Shikuma, MD

2. HIV and Cardiovascular Disease • HIV-infected individuals have an increased risk of cardiovascular mortality, including sudden death • Possible risk factors are: – High rates of dyslipidemia, diabetes, and hypertension – Chronic vascular inflammation due to HIV per se

3. Importance of QT Interval • QT interval represents ventricular repolarization • Prolonged QT interval increases the risk of developing ventricular tachyarrhythmias and sudden cardiac death • Many factors prolong QT interval • How does HIV affect QT interval?

4. Purpose • Certain drugs, including protease inhibitors, have been associated with prolonged QT interval in HIV-infected individuals • Few studies have looked at QT interval and QT dispersion • We sought to identify factors that may increase QT interval and QT dispersion in HIV-infected individuals

5. Methods • Retrospective analysis of 105 HIV-infected patients in the Healthy Heart Study • Demographic information and medical histories were obtained by self-report • All leads of the electrocardiogram were simultaneously obtained • QT interval lengths were manually measured to one thousandth of a second using ImageJ

6. Heart-rate Corrected QT Interval (QTc) and QT Dispersion (QTd) • QT interval corrected for heart rate using Bazett’s formula • Prolonged QTc > 440 ms • QTd is the regional variation in ventricular repolarization – QTd = QTcmax – QTcmin – Abnormal QTd > 80 ms

7. Baseline Characteristics

8. Prolonged QTc vs Normal QTc

9. Abnormal QTd in HIV Individuals with Prolonged and Normal QTc

10. QTc and QTd in HIV Individuals r=0.41, p < 0.001

11. QTc and Age in HIV Individuals r=0.19, p=0.05

12. Summary • Higher rate of prolonged QTc (12.4%) found in the cohort compared to published population norms (6.3%) (p=0.05) • Higher rate of abnormal QTd (15.2%) found in the cohort compared to published population norms (2.0%) (p<0.05) • No significant associations found between prolonged QTc and abnormal QTd, and antiretroviral medications, CD4, and viral load • Significant correlation found between QTc and QTd • QTc, but not QTd, significantly correlated with age

13. Limitations • No control group • Small number of patients • Retrospective study • Medical histories were obtained from the patients by self-report • Multiple factors which affect QTc and QTd were not accounted for in this study

14. Conclusions • Higher rates of prolonged QTc and abnormal QTd in HIV-infected individuals • These abnormalities are associated with increased cardiovascular disease and sudden death • Further studies would be required to determine the factors associated with QTd abnormality and QTc prolongation in HIV-infected individuals

15. Acknowledgements Thank you to Dr. Chow, Dr. Shikuma, the Hawaii AIDS Clinical Research Program staff, and the participants of the Healthy Heart Study