The ACC Foundation (ACCF), in partnership with 10 other leading professional societies, released its newest set of appropriate use criteria (AUC) on June 11, this time focused on peripheral vascular ultrasound and physiological testing.
"This is the first systematic and comprehensive evaluation looking at appropriate indications for vascular testing, such as ultrasound or functional testing," said Emile R. Mohler III, MD, FACC, director of vascular medicine for the University of Pennsylvania Health System and chair of the writing committee.
This newest set of AUC focuses on 159 indications for which ultrasound and physiological testing are frequently considered. Of the 255 total indications (with the inclusion of surveillance timeframes), 117 were rated as appropriate, 84 were rated as uncertain, and 54 were rated as inappropriate.
In particular, arterial vascular testing was found to be "appropriate" in about half of the clinical situations evaluated. For example, there was "significant consensus regarding the appropriateness of cerebrovascular duplex ultrasound for evaluation of the patient with signs or clinical symptoms of cerebrovascular disease with 7 of 8 clinical indications rated as appropriate and 1 clinical indication rated as uncertain."
Overall, vascular studies were deemed appropriate when clinical signs and symptoms were the main reason for testing. For example, Mohler explained, it is reasonable to order a lower extremity vascular study for a patient who reports calf pain upon walking that resolves with rest. Tests that were conducted in patients with existing atherosclerotic disease or to establish a "baseline" after a revascularization procedure were also considered appropriate based on ratings.
Of the indications rated as "uncertain," the panel noted variations in practice and important gaps in the evidence that made it difficult to determine appropriateness. For example, there was uncertainty regarding the use of cerebrovascular duplex for assessment of the asymptomatic patient with risk factors or comorbidities associated with carotid artery stenosis, with 6 of 7 indications receiving an uncertain score. According to the writing panel, clinical and cost-effectiveness studies on non-invasive vascular testing are needed in order to gain more clarity.
Notably, one in five uses of vascular testing were determined to be "inappropriate," meaning that although doing the test does not cause harm, the information gleaned would not further inform clinical judgment. A few examples include:
- Ordering a carotid screening ultrasound for assessment of patients with low Framingham risk scores or patients with low or intermediate Framingham risk scores who have already undergone another imaging risk assessment.
- Ordering a renal or mesenteric artery ultrasound for patients with peripheral artery disease with well controlled hypertension on one medication.
- Choosing to perform an abdominal ultrasound in a patient with non-specific lower extremity discomfort.
- Ordering a mesenteric artery ultrasound as an initial test to evaluate the patient with chronic constipation or diarrhea.
- Performing a follow-up study for a patient with a normal baseline study who has no new symptoms.
"As imaging technology and clinical applications continue to advance, the health care community needs to understand how to best incorporate these technologies into daily clinical care," said Dr. Mohler. "These appropriate use criteria should guide clinicians as to what is an appropriate and inappropriate test so that we can rationally decide when testing is the best next step, especially in this time of cost-effectiveness in medicine."
In addition to looking at the reasons for ordering these tests, the work group also sought to determine how frequently repeat testing is needed in clinical practice in light of the need for ongoing surveillance in some patients.
Mohler stressed that the new AUC should not supersede sound clinical judgment for individual patients. The document also outlines key research areas moving forward. A related report presenting appropriate use criteria for vascular laboratory testing to evaluate venous circulation is expected to be released in late fall of this year.
The AUC were developed in collaboration with the American College of Radiology, American Institute of Ultrasound in Medicine, American Society of Echocardiography, American Society of Nephrology, Intersocietal Commission for the Accreditation of Vascular Laboratories, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society of Interventional Radiology, Society for Vascular Medicine and Society for Vascular Surgery. The document is further endorsed by the American Academy of Neurology, American Podiatric Medical Association, Society for Clinical Vascular Surgery, Society for Cardiovascular Magnetic Resonance, and Society for Vascular Ultrasound.