Circ: Mandating CMR stress tests for lower-risk ACS patients adds costs

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Stress Test - 46.22 Kb
Nuclear stress tests assist in assessing patients who present with chest pain.
Source: Miriam Hospital, Providence, R.I.

Allowing physicians to choose a stress test modality for lower-risk patients presenting at an emergency department with chest pain was more cost-effective than mandating a cardiac magnetic resonance (CMR) stress test, according to a study published online Nov. 29 in Circulation: Cardiovascular Imaging. In an observation unit (OU), provider choice care resulted in similar results as CMR-mandated care, with a lower price tag.

In a previous randomized trial, Chadwick D. Miller, MD, MS, of the department of emergency medicine at Wake Forest School of Medicine in Winston-Salem, N.C., and colleagues had compared a strategy using CMR stress testing in patients with chest pain who were at intermediate to high risk of acute coronary syndromes (ACS) with inpatient care to determine one-year healthcare costs. They concluded that the CMR strategy implemented in an OU was more cost-effective.

The authors designed the present clinical trial to test whether mandatory CMR stress testing in an observation unit setting compared with provider choice would also provide cost savings in lower-risk patients. Their study population consisted of patients who presented in a single center’s emergency department with acute chest pain or symptoms of ACS. The strategies were compared first on efficiency, measured as length of stay (LOS); and second on cost and efficiency, measured as cardiac catheterizations without coronary intervention, appropriateness of cardiovascular admission decisions and clinical outcomes.

To be eligible, patients had to have a Thrombolysis Myocardial Infarction (TIMI) risk score of greater or equal to 1, or a physician diagnosis of likely ACS, a referral to an OU and be 18 years old or older. Patients not deemed safe for OU, with contraindications for CMR and other criteria indicating unsuitability were censored.

The final study cohort of 120 patients was randomized to a group that received OU care with stress CMR imaging (60 patients) or OU care with a provider-selected stress test (60 patients). Within the provider’s choice group, 62 percent underwent stress echo, 32 percent CMR, 3 percent cardiac catheterization, 2 percent nuclear tests and 2 percent coronary CT.

Both groups had similar LOS and outcomes. The median LOS was 23.8 hours in the provider choice group compared with 24.2 hours in the CMR group. There was a very low incidence of non-therapeutic catheterization and a high rate of appropriateness of admission decisions in each group.

Mean and median costs were higher in the CMR group, $2,586 vs. $2,050 and $2,005 vs. $1,686, respectively. The researchers attributed higher CMR costs primarily to pharmacy and noninvasive imaging costs.

“In these lower risk patients, it appears the physician’s ability to tailor testing to the individual patient, while considering institutional imaging strengths, may be a key to enhanced healthcare efficiency,” Miller and colleagues wrote.

They added that the results showed that physician discretion appeared favorable in this patient population and circumstances.

“In the PC [provider choice] group in this study, providers carefully selected the patient’s imaging modality,” they pointed out. “For instance, in PC participants with prior MIs (a group that physicians may perceive to be a higher risk of ACS), all received CMR perfusion stress imaging with techniques that could discriminate old from new infarcts.”

The high number of CMR stress tests in the provider care group likely added costs in that group, they wrote. Excluding these patients would have led to selection bias, they argued, and restricting patients from these tests potentially would be unethical. They advocated a larger study be conducted to evaluate costs and effectiveness.