Update to stable ischemic heart disease guideline clarifies use of coronary angiography
A focused update to a guideline on the diagnosis and management of patients with stable ischemic heart disease clarifies when coronary angiography is appropriate to perform in that patient population.
The authors of the update also considered new evidence on chelation therapy for patients with stable ischemic heart disease and found its usefulness uncertain, and upgraded the recommendation that CABG is preferable to PCI in patients with type 2 diabetes and multivessel CAD.
The document is an update of the 2012 guideline on diagnosis and management of patients with stable ischemic heart disease from the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. The writing group, chaired by Stephan D. Fihn, MD, MPH, consisted of representatives from ACC, AHA, the American Association for Thoracic Surgery, the Preventive Cardiovascular Nurses Association, the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons.
Invasive coronary angiography
“It was not clear from the initial guideline when proceeding directly to diagnostic coronary angiography would be an option,” Srihari S. Naidu, MD, FSCAI, FACC, FAHA, the representative to the writing group from SCAI, told Cardiology Today. “Virtually all patients with potential ischemic heart disease should be evaluated by some type of stress testing. The field has evolved toward that … but there are areas where there is a gap, in which stress testing may not be adequate or may not be absolutely necessary prior to diagnostic angiography.”
For most patients in this population, according to the writing group, noninvasive stress testing should be the initial strategy. “Coronary angiography is appropriate only when the information derived from the procedure will significantly influence patient management and if the risks and benefits of the procedure have been carefully considered and understood by the patient,” they wrote. “Coronary angiography to assess coronary anatomy for revascularization is appropriate only when it is determined beforehand that the patient is amenable to, and a candidate for, percutaneous or surgical revascularization.”
If a noninvasive stress test is abnormal and a diagnosis of CAD is uncertain, many doctors proceed to invasive coronary angiography, but “in some patients, multidetector CT angiography may be appropriate and safer than routine invasive angiography for this purpose,” Fihn and colleagues wrote.
Appropriate use of angiography
The panel concluded that coronary angiography:
- Is useful in patients with presumed stable ischemic heart disease and unacceptable ischemic symptoms despite medical therapy and who are appropriate for and willing to undergo revascularization;
- Is reasonable to define the extent and severity of CAD in patients whom noninvasive testing (but not stress testing) indicates a high probability of severe ischemic heart disease and who are appropriate for and willing to undergo revascularization;
- Is reasonable in patients with suspected symptomatic stable ischemic heart disease who cannot undergo diagnostic stress testing or whose stress tests were inconclusive when it is likely that findings will result in important changes to therapy;
- May be considered in patients with stress test results of acceptable quality that do not suggest CAD presence, but in whom clinical suspicion of CAD remains high and for whom it is likely that findings will result in important changes to therapy.
“In this day and age, when cost effectiveness is important, it’s imperative to make sure you do the right test from the get-go,” Naidu, director of the cardiac catheterization laboratory, the interventional cardiology fellowship program and the hypertrophic cardiomyopathy treatment center at Winthrop University Hospital, Mineola, N.Y., said. “A challenge was figuring out when stress testing is not necessary and going right to angiography is reasonable.
“One scenario is patients who you think have ischemic symptoms and are candidates for revascularization and whose symptoms are not controlled with medication; that was an easy one,” Naidu said. “A more controversial one was patients who … look like they have severe disease that would warrant revascularization. Examples include those with longstanding diabetes, end-organ damage or peripheral vascular disease. In those kinds of patients, it does not make sense to do stress testing first when there’s such a high pretest probability of disease that will require some kind of invasive treatment; it would make sense, financially and from a patient safety perspective, to proceed directly to coronary angiography.”
The recommendation regarding patients with stress test results indicating no CAD presence but in whom their doctor highly suspects CAD may be controversial, but “in real-world practice, it’s very helpful to rule out coronary disease in those kinds of patients,” Naidu said. “It shouldn’t be done routinely, but it should be done in patients in whom you think the information to either exclude or rule in coronary disease is absolutely necessary for good patient management.”
CABG vs. PCI
The panel strengthened its recommendation that CABG is preferable to PCI for patients with type 2 diabetes and multivessel CAD, upgrading it from a Class IIa recommendation to a Class I recommendation. It also added a Class I recommendation that a Heart Team approach should be used for decision-making in that patient population.
The upgrade was primarily prompted by the results of the FREEDOM trial, which found that among patients with diabetes and multivessel CAD, the outcome of death, nonfatal MI or nonfatal stroke at 5 years was less likely to occur in those undergoing CABG compared with those undergoing PCI with DES (18.7% vs. 26.6%; P=.005), Naidu told Cardiology Today.
“We kept the same overall reasoning that we had in the first guideline,” he said. “But we modified the language to identify the patient population in whom Class I makes sense. That means patients with diabetes who have significant complex disease, the higher SYNTAX tertiles; they should also have a [left internal mammary artery] that can be used and should be a good surgical candidate.”
The panel modified its recommendation on chelation therapy for improving symptoms or reducing CV risk in patients with stable ischemic heart disease. The 2012 guideline recommended against it, while the update, prompted by positive but modest results from the TACT trial, states that its usefulness is uncertain.
The panel also reviewed literature on enhanced external counterpulsation for relief of refractory angina in patients with stable ischemic heart disease, but did not change the recommendation that it may be considered for that indication. – by Erik Swain
For more information:
Disclosure: Naidu reports no relevant financial disclosures. See the full document for a list of relevant financial disclosures for members of the writing group and task force.