Major adverse coronary events status post percutaneous coronary intervention in Veterans exposed to Agent Orange versus non-exposed

Abstract: INTRODUCTION: United States Veterans who served in Vietnam, the Korean Demilitarized Zone, or Thailand Air Force bases from 1962 to 1971 were likely exposed to Agent Orange, as approximately 107 million pounds of the chemical were sprayed in the areas where the fighting occurred. Agent Orange was an herbicide used by the United States military to kill the jungle, foliage, tall grasses, bushes, and weeds. Agent Orange contained 2,3,7,8-tetrachlorodibenzo-p-dioxin, the most toxic form of dioxin, which has been associated with multiple disease processes and cardiac issues. MATERIALS AND METHODS: An original quantitative descriptive, retrospective cohort, secondary data analysis study was conducted utilizing data collected by the Veterans Health Administration (VHA) via the Cardiovascular Assessment, Reporting, and Tracking System for Cath Labs and the Computerized Patient Record System. A new and innovative Structured Query Language report was created for data mining. Statistical tests included Chi-square tests, two-sample t-tests, prevalence, logistic regression, and odds ratios. A secondary analysis was conducted to assess for confounders, associations, and differences. RESULTS: Veterans exposed to Agent Orange status post (s/p) percutaneous coronary intervention (PCI) have significantly higher body mass index (P ≤ .01), with a higher percentage of obesity (45.4% vs. 41.0%) and severe obesity (7.0% vs. 6.1%). There is a higher prevalence of those exposed to Agent Orange in the white (85% vs. 79.3%, P ≤ .01) and non-Hispanic/Latino (93.9% vs. 92.9%, P ≤ .01) male population. There is a higher prevalence of hypertension (91.3% vs. 90.7%, P = .03), hyperlipidemia (91.7% vs. 90.1%, P ≤ .01), and diabetes (53.5% vs. 49.8%, P ≤ .01) in those exposed vs. non-exposed. Lastly, there is a higher prevalence (1.8% vs. 1.5%) and fully adjusted odds 1.22 (95%CI: 1.08, 1.37; P = .0011) of coronary artery bypass graft surgery (CABG). CONCLUSIONS: Veterans exposed to Agent Orange are high-risk cardiovascular patients with a higher prevalence and odds of CABG s/p PCI. The increased prevalence of hypertension, hyperlipidemia, obesity, severe obesity, and diabetes in Veterans exposed to Agent Orange s/p PCI suggests that Agent Orange may contribute to the development of these disease processes. Strengths include the quality and longevity of the data collected, the Promise to Address Comprehensive Toxics (PACT) Act supporting Agent Orange research, and the advanced age of the Veterans increases the likelihood of cardiovascular disease. Weaknesses include the inability to quantify and confirm Agent Orange exposure, the inability to determine causation, and the VHA registrar's office could have erroneously assigned the Agent Orange disability flag by not verifying the service location. This study impacts the care of the Veterans s/p PCI; providers should assess the comorbidities, coronary artery disease progression, number of vessels affected, tortuosity of the cardiac vessels, location of the coronary artery lesion(s), size of the lesion(s), and the number of stents needed to determine if repeat PCI is the preferred treatment over CABG. Future studies should include the newly categorized Veterans exposed to Agent Orange from the PACT Act screenings, the CABG outcomes, the characteristics of the coronary lesions, the type of stent(s), and the medications prescribed at the time of the original PCI.