Among intermediate to high-risk patients with chest pain, we have shown that a cardiac magnetic resonance (CMR) stress-test strategy implemented in an observation unit (OU) reduces 1-year healthcare costs compared to inpatient care. In this study, we compare two OU strategies to determine among lower-risk patients if a mandatory CMR stress test strategy was more effective than a physicians’ ability to select a stress test modality.
Methods and Results
Upon ED arrival and referral to the OU for management of low to intermediate-risk chest pain, 120 individuals were randomized to receive an a) CMR stress imaging test (n=60), or b) a provider selected stress test (n=60: stress echo [62%], CMR (32%), cardiac catheterization (3%), nuclear (2%), and coronary CT [2%]). No differences were detected in length of stay (median CMR = 24.2 hours vs 23.8 hours, p=0.75), catheterization without revascularization (CMR=0% vs 3%), appropriateness of admission decisions (CMR 87% vs 93%, p=0.36), or 30-day ACS (both 3%). Median cost was higher among those randomized to the CMR mandated group ($2005 vs $1686, p<0.001).
In patients with lower-risk chest pain receiving ED-directed OU care, the ability of a physician to select a cardiac stress imaging modality (including echocardiography, CMR, or radionuclide testing) was more cost effective than a pathway that mandates a CMR stress test. Contrary to prior observations in individuals with intermediate to high-risk chest pain, in those with lower risk chest pain, these results highlight the importance of physician-related choices during ACS diagnostic protocols.
Clinical Trial Registration
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00869245.