The decision to perform stress testing in the evaluation of chest pain is often based on the pretest likelihood of coronary artery disease (CAD).1-7 Cardiac risk scores, which incorporate smoking status, blood pressure, diabetes mellitus, and cholesterol levels, also may provide further risk stratification.8-11 Assuming that the prevalence of CAD increases with age, young adults could be deemed low risk, not warranting cardiac screening.12
Professional society guidelines from the American College of Cardiology/American Heart Association and American College of Physicians4,5 recommend stress testing as the initial diagnostic test for CAD in symptomatic patients; additionally, the guidelines also suggest that screening stress tests may confer primary prevention benefit in intermediate-risk asymptomatic patients.9,13 Exercise treadmill testing is considered the initial modality of choice, given its technical ease and lower cost, compared with stress echocardiography.14
Previously published reports have shown the limited use of stress testing to screen young asymptomatic adults.15-17 Because this patient demographic typically has a low pretest likelihood of CAD, positive stress tests are often false-positive results.7,18 The consequence of false-positive testing may be unnecessary additional cardiac testing, potentially leading to more patient harm than benefit.18,19 For active-duty service members, false-positive testing also has the potential to affect worldwide deployability and/or sea duty status while further risk stratification is performed; as a result, mission readiness may be impacted.Although the number of clinic visits for chest pain has declined, there has been a discordant increase in the rates of stress testing in the US.20-22 Additionally, the rate of stress testing among young adults, specifically in the 25- to 34-year age group, has increased in recent years. Given the rising use of stress tests in the young patient population, the clinical use of stress testing needs to be reassessed.
Although much of the literature has already demonstrated the low value of stress testing in young asymptomatic adults, no data currently exist regarding its outpatient use in evaluating young symptomatic patients. The military represents a predominantly young cross-section of the general population suitable for exploring this topic. Using a cohort of active-duty service members, we aimed to determine the use of outpatient stress testing in evaluating young patients with atypical chest pain.
The US Department of Defense (DoD) Military Health System Database Repository (MDR) and Comprehensive Ambulatory Professional Encounter Record (CAPER) were the data sources for this study. The MDR contains continually updated, longitudinal electronic medical records (EMRs) for nearly 1.4 million active-duty service members and is composed of administrative, medical, pharmacy, and clinical data. The Naval Medical Center Portsmouth (NMCP) Institutional Review Board approved this study.
We performed chart reviews of service members aged 18 to 35 years who received cardiac stress testing at NMCP, an academic tertiary care center, within 30 days after an office visit for atypical chest pain between October 1, 2010, and September 30, 2015. Atypical chest pain was defined as any outpatient claim with ICD-9 code, 786.5x, in the primary diagnosis field (Table 1).4