Clinical Outcomes After Cardiac Stress Testing Among US Patients Younger Than 65 Years.

backgroundScientific statements have championed the measurement of clinical outcomes after cardiac stress testing to better define their value. Using contemporary national data, we sought to describe the characteristics of patients who experience outcomes after stress testing. METHODS AND

resultsUsing administrative claims from a large national private insurer, we conducted an observational cohort study of patients without cardiovascular disease aged 25 to 64 years who underwent stress testing from 2006 to 2011 and had at least 1 year of membership in the insurance company before and after testing. We used Kaplan-Meier time-to-event analyses to determine rates of acute myocardial infarction (AMI), elective coronary revascularization, and coronary angiography without revascularization in the year following testing. We used logistic regression to determine factors associated with outcomes, and stratified the cohort into quintiles based on likelihood of experiencing AMI and/or revascularization to describe the characteristics of patients at highest and lowest risk. Among 553 027 patients who underwent stress testing (mean age 50 years, 49% women, 73% white), 0.8% were hospitalized for AMI, 1.8% underwent elective coronary revascularization, and 2.5% underwent coronary angiography without revascularization within 1 year. Patients who were older, male, and white were more likely to undergo subsequent revascularization. Patients in the lowest likelihood quintile were young (mean age 40 years), frequently women (84.7%), had a low incidence of coexisting conditions (5.2% with diabetes mellitus), and had a 0.5% rate of AMI and/or revascularization.

conclusionsThe proportion of US patients younger than 65 who had AMI and/or coronary revascularization after stress testing was low. Assessing risk of subsequent outcomes may be useful in improving patient referrals for stress testing.