Application of appropriate use criteria to cardiac stress testing in the hospital setting: limitations of the criteria and areas for improved practice.

BACKGROUND: Imaging cardiac stress test use has risen significantly, leading to the development of appropriate use criteria. Prior studies have suggested the rate of inappropriate testing is 13% to 14%, but inappropriate testing in hospitalized patients has not been well studied. HYPOTHESIS: Appropriate use of stress testing in hospitalized patients is not comparable to the ambulatory setting.
METHODS: We studied 459 consecutive patients referred for imaging stress tests (nuclear imaging or stress echocardiography) at a single institution over a 6-month period. Appropriate use was determined by research cardiologists blinded to patient outcomes.
RESULTS: Most tests (68%) were in patients with chest pain or possible acute coronary syndrome (ACS). Another 20% were for preoperative evaluation. The rate of inappropriate testing was 13%. Imaging modality did not correlate with appropriate use. Only 2% of the chest pain or possible ACS were inappropriate, compared to 49% of the preoperative exams (P < 0.001). The most common reason a test was considered inappropriate was for a low-risk patient for preoperative exam (77% of inappropriate tests). Using Thrombolysis in Myocardial Infarction score 0 to define inappropriate testing in the possible ACS cohort might make an additional 27% inappropriate.
CONCLUSIONS: The rate of inappropriate use of cardiac stress testing with imaging in the inpatient setting is similar to that in the ambulatory setting. However, there is wide variation in inappropriate testing based on the indication for the test. Taking risk into consideration in possible ACS patients could result in a larger number of tests being considered inappropriate.