Abstract 15906: The Yield of Downstream Tests After Exercise Treadmill Testing: A Prospective Cohort Study
Background: The utility of additional cardiac diagnostic testing following exercise treadmill tests (ETT) is not well characterized. Our aim was to estimate the frequency and yield of downstream testing following exercise treadmill testing (ETT) and identify predictors of patients who are most and least likely to benefit from additional testing.
Methods and Results: We followed a cohort of 3,345 consecutive individuals without known coronary artery disease referred for a clinical ETT at large medical center. Downstream tests included all tests (invasive and noninvasive) within six months of ETT. Overall, 332 (9.0%) underwent noninvasive imaging while 84 (2.3%) were referred directly to invasive angiography. The rates of positive downstream testing following negative, inconclusive and positive ETT were 6.4%, 14.2% and 32.9% respectively. Over a mean follow-up of 2.5±1.1 years, there were 76 (2.2%) adverse events (cardiovascular death, myocardial infarctions, and coronary revascularizations) with annual incidence of 0.2%, 1.3% and 12.4% following negative, inconclusive and positive ETT respectively (P<0.001). Among 1,043 (28.5%) inconclusive ETT studies, rapid recovery of ECG changes (n=134, 13%) was associated with negative downstream test results and excellent prognosis while typical angina despite negative ECG (n=103, 10%) was associated with a higher frequency of positive downstream tests and adverse prognosis (P<0.001).
Conclusions: Among patients referred for additional testing after ETT, the lowest yield was observed among individuals with rapid recovery of ECG changes or negative ETT while the highest yield was observed among those who developed typical angina despite negative ECG or had a positive ETT. These findings may be used to identify patients who are most and least likely to benefit from additional testing.
- © 2013 by American Heart Association, Inc.