Cardiovascular
Cardiovascular Disease and Post-traumatic Stress Disorder in World Trade Center Exposed Firefighters Madeline Cannon* Madeline Cannon Hillel W. Cohen Charles B. Hall Nadia Jaber David Prezant Rachel Zeig-Owens
Background: World Trade Center (WTC) exposure is associated with cardiovascular disease (CVD) in firefighters, other first responders, and survivors. However, the extent to which this is caused by particulate matter or post-traumatic stress disorder (PTSD) is unclear.
Aim: To assess if PTSD is a mediator of the association between WTC exposure and CVD in male firefighters.
Methods: We prospectively followed 9,758 male WTC-exposed firefighters from 9/11/01 (9/11) to 9/11/22. Cox regression models analyzed WTC exposure and CVD, adjusted for race/ethnicity and age and positive screen for PTSD symptoms (y/n) at first exam. CVD included electronic medical record of myocardial infarction, stroke, angina, coronary artery surgery, angioplasty, transient ischemic attack, cardiomyopathy, aortic aneurysm, peripheral arterial vascular intervention, carotid artery surgery, or CVD death. Age and PTSD were also modeled as time-dependent covariates, including all exams with complete data. A causal mediation analysis assessed PTSD as a mediator of the association between WTC exposure and CVD.
Results: 1,027 participants had a CVD event. Compared to firefighters who arrived at the WTC site from 9/12/01 to 9/24/01, those who arrived in the morning on 9/11 had a 34% increased hazard of CVD (95% CI=1.11-1.62), while those arriving in the afternoon had a 20% increased hazard (CI=1.04-1.38). PTSD at first exam was not associated with CVD (HR=1.02, CI=0.84-1.25). In the time-dependent analysis, arrival in the morning of 9/11 (HR=1.30, CI=1.08-1.57), arrival in the afternoon of 9/11 (HR=1.18, CI=1.02-1.36), and PTSD (HR=1.38, CI=1.14-1.68) were all associated with CVD. PTSD symptoms mediated 10% of the association between arrival in the morning of 9/11 and CVD, with a controlled direct effect of 1.30 (CI=1.08-1.57) and a natural indirect effect of 1.03 (CI=1.01-1.04).
Conclusion: PTSD symptoms partially mediate, albeit minimally, the association between WTC exposure and CVD among firefighters.