Setting: Outpatient
Numerator: Patients who have had a stress echocardiography or SPECT MPI study in the five-year period following a coronary artery bypass graft (CABG) procedure.
Denominator: Patients who have had a CABG procedure.
Exclusions: All tests performed in the first six months post-CABG; any patient with clinical risk predictors for silent ischemia or accelerated coronary artery disease (CAD) (e.g., diabetes); and any patient who undergoes a catheterization, percutaneous coronary intervention (PCI), or CABG procedure in the six months following the post-revascularization Stress Echocardiography or SPECT MPI.

A review of stress echocardiography appropriateness criteria for specific clinical scenarios was recently completed and published by The American College of Cardiology Foundation (ACCF) and the American Society of Echocardiography (ASE). Review of SPECT MPI appropriateness criteria for specific clinical scenarios was completed and published by ACCF and the American Society of Nuclear Cardiology (ASNC). The purpose of the published criteria is to "help guide a more efficient and equitable allocation of health care resources."

The proposed measure seeks to estimate relative use of stress echocardiography and SPECT MPI in asymptomatic patients less than five years after a CABG procedure.

The appropriateness criteria provided specific guidance that use of stress echocardiography is not appropriate for risk assessment within five years for asymptomatic patients. The appropriateness score assigned to the use of stress echocardiography for the indication is two (2). Scores of 1-3 are defined as inappropriate (the test is generally not indicated). Use of SPECT MPI for the indication was scored at six (6). Scores of 4 -6 are defined as uncertain.

Clinical guidelines and literature cited the importance and value of stress echocardiography for low-risk patients, specifically those who are asymptomatic after CABG, as being of limited value. Application of the appropriateness criteria was recently conducted by an academic medical center. The study concluded that eighteen percent of stress echocardiography procedures were performed for inappropriate reasons. Specific to risk assessment post-revascularization, the study found no inappropriate studies, however, eighteen of sixty-four studies (28%) reviewed were found to be unclassified or uncertain. Given the small sample size for the indication, further analysis is needed to determine potential financial relevance.

The guidelines and literature cited show the evidence in support of the measure. However, one study pointed out the lack of randomized trials of exercise testing in asymptomatic patients, and as a result, its value is difficult to assess. The ROSETTA-CABG registry study exemplifies the most significant examination to date related to the use of stress echocardiography, including whether its use is acceptable among patients who have recently undergone CABG surgery. However, patients were not stratified by symptoms.

As indicated above, further studies stratifying patients by symptoms may provide new evidence. However, no changes are anticipated. The science underlying the measure has not undergone significant changes, nor is new scientific evidence likely to emerge in the next 12 months.

Limited information was found after conducting the environmental scan in the area of usability. However, the experience in one academic setting suggests that the measure is eminently usable. Guidelines set forth by the American College of Cardiology, American Heart Association, and American Society of Nuclear Cardiology give a IIb classification (usefulness and efficacy is less well-established) related to the assessment of active, asymptomatic patients who have remained stable for up to 5 years after CABG surgery.

The measure is intended to align with published appropriateness criteria rendering the results easily understandable to the health care audience and potentially useful in decision-making. The health care provider can use the results to reduce cost without compromising the quality of care.

There are few measures that address imaging efficiency that have been developed despite the recent tremendous growth in imaging in the United States. There are no closely related existing measures.

Echocardiography and SPECT MPI are procedures that must be ordered by a physician to be performed. Therefore, there is the distinct opportunity for the physician not to order an unnecessary study, and for the rendering physician to ensure that an unneeded study is not performed.

The measure could be applied in any setting where stress echocardiography and SPECT MPI are performed after CABG; however, the focus of the measure is the outpatient facility setting.

The specifications are anticipated to be readily applied to Medicare claims data to estimate the use of stress echocardiography and SPECT MPI in the five years following a CABG procedure. As the measure will be claims-based and no 'right' number can be set in advance, data will be gathered and analyzed to identify outlier facility practices in this area.

Appropriate codes must be documented to assure that the population and studies are properly identified. We can expect some minimal distortion in the results due to imprecise coding.

To implement the measure, patient identifying information is used to link the procedure to antecedent claims or diagnostic claims. After this link has been determined and the numerators and denominators for the measure have been counted, the patient identifying information is eliminated from the file. The reporting of the measures is at an aggregate level that does not indicate any claim or person-level detail in compliance with HIPAA requirements.