Comparative effectiveness of diagnostic testing strategies in emergency department patients with chest pain: an analysis of downstream testing, interventions, and outcomes

Abstract

Importance: Patients presenting to the emergency department (ED) with chest pain whose evaluation for ischemia demonstrates no abnormalities receive further functional or anatomical studies for coronary artery disease; however, comparative evidence for the various strategies is lacking and multiple testing options exist.

Objective: To compare chest pain evaluation pathways based on their association with downstream testing, interventions, and outcomes for patients in EDs.

Design, setting, and participants: Retrospective analysis of health insurance claims data for a national sample of privately insured patients from January 1 to December 31, 2011. Individuals with a primary or secondary diagnosis of chest pain in the ED were selected and classified into 1 of 5 testing strategies: no noninvasive testing, exercise electrocardiography, stress echocardiography, myocardial perfusion scintigraphy, or coronary computed tomography angiography.

Main outcomes and measures: The proportion of patients in each group who received a cardiac catheterization, coronary revascularization procedure, or future noninvasive test as well as those who were hospitalized for an acute myocardial infarction (MI) during 7 and 190 days of follow-up.

Results: In 2011, there were 693 212 ED visits with a primary or secondary diagnosis of chest pain, accounting for 9.2% of all ED encounters. After application of the inclusion and exclusion criteria, 421 774 patients were included in the final analysis; 293 788 individuals did not receive an initial noninvasive test and 127 986 did, representing 1.7% of all ED encounters. Overall, the percentage of patients hospitalized with an MI was very low during both 7 and 190 days of follow-up (0.11% and 0.33%, respectively). Patients who did not undergo initial noninvasive testing were no more likely to experience an MI than were those who did receive testing. Compared with no testing, exercise electrocardiography, myocardial perfusion scintigraphy, and coronary computed tomography angiography were associated with significantly higher odds of cardiac catheterization and revascularization procedures without a concomitant improvement in the odds of experiencing an MI.

Conclusions and relevance: Patients with chest pain evaluated in the ED who do not have an MI are at very low risk of experiencing an MI during short- and longer-term follow-up in a cohort of privately insured patients. This low risk does not appear to be affected by the initial testing strategy. Deferral of early noninvasive testing appears to be reasonable.

Figure 1. Flow Diagram of Cohort Selection Process

Cath indicates coronary catheterization; CCTA, coronary computed tomography angiography; EE, exercise electrocardiography; MI, myocardial infarction; MPS, myocardial perfusion scintigraphy; PCI, percutaneous coronary intervention; and SE, stress echocardiography.

Figure 2. Adjusted Odds Ratios for Cardiac Catheterization, Revascularization, and Hospitalizations for Myocardial Infarction (MI) During 7 and 190 Days of Follow-up vs No Testing

CCTA indicates coronary computed tomography angiography; EE, exercise electrocardiography; MPS, myocardial perfusion scintigraphy; and SE, stress echocardiography. Vertical lines indicate the reference group (those who did not receive initial testing); limit lines, 95% CI.

Figure 3. Adjusted Odds Ratios for Second Noninvasive Testing During 190 Days of Follow-up

CCTA indicates coronary computed tomography angiography; EE, exercise electrocardiography; MPS, myocardial perfusion scintigraphy; and SE, stress echocardiography. Vertical lines indicate the reference group (those who did not receive initial testing); limit lines, 95% CI.