Abstract 15928: Cardiovascular Stroke Nursing Best Abstract Award: Association of Posttraumatic Stress Disorder With Repolarization Heterogeneity in Veteran Twins
Introduction: Posttraumatic stress disorder (PTSD) is a debilitating psychological condition that is prevalent amongst veterans and associated with increased risk of CHD. The elevated sympathetic nervous system activity that characterizes PTSD could affect cardiac electrophysiology and increase the risk of sudden cardiac death. We hypothesized that PTSD is associated with increased microvolt T-wave alternans (TWA), a measure of repolarization heterogeneity that is associated with increased risk of sudden cardiac death.
Methods: We studied 186 male twins from the Vietnam Era Twin Registry. The twins wore a Holter monitor for 24 hours, and a thorough baseline assessment was performed, including a structured clinical interview for diagnosing psychiatric disorders, as well as cardiovascular assessment for traditional risk factors. The maximum T-wave alternans in 24 hours of monitoring was measured using the modified moving average method (GE Medical). Mixed models were used in analysis to assess covariance within pairs, and co-twin control modeling was performed to evaluate genetic and familial confounding.
Results: The average (SD) age was 57 (2) years, and 28 twins had PTSD symptoms within 30 days of assessment. The twins with active PTSD had a 28% higher TWA compared to the others (p=0.03). This relationship did not change after adding heart rate to the model; further addition of CHD history and traditional CHD risk factors to the model also did not significantly influence the association. When analyzing the association within 22 pairs discordant for PTSD (to adjust for familial factors), the brother with PTSD had a 42% higher TWA compared to the brother without PTSD in fully adjusted models. An interaction with zygosity was also found (p=0.03), such that the effect was significant within the dizygotic (10 pairs), but not monozygotic twin pairs (12 pairs). Within the dizygotic twin pairs, the PTSD brother was found to have a 127% (p=0.001, adjusted) higher TWA compared to the non-PTSD brother.
Conclusion: PTSD is associated with increased TWA in veteran twins, but this relationship is confounded by genetic factors. This suggests common genetic factors may predispose to both PTSD and repolarization heterogeneity. Further research is warranted.
Author Disclosures: A.J. Shah: None. Z. Khan: None. N. Isakadze: None. E. Veledar: None. J. Goldberg: None. J.D. Bremner: None. R. Lampert: None. V. Vaccarino: None.
- © 2016 by American Heart Association, Inc.