Ad hoc PCI, CABG in Type 2 Diabetes Featured in Stable CAD Guidelines Update

Marlene Busko

February 16, 2016

DALLAS, TX — Cautions against engaging in PCI prematurely after angiography in patients with diabetes and more broadly as well as sharpened recommendations for CABG in diabetics feature prominently in a new focused update to the 2012 clinical-practice guidelines for patients with stable ischemic heart disease (IHD)[1].

Still, about 95% of the 2012 guidelines are unchanged with the addition of this update, writing committee chair Dr Stephan D Fihn (VA Puget Sound Health Care System, Seattle, WA) told heartwire . The document from the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, the American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons was published online July 28, 2014 in Circulation, the Journal of the American College of Cardiology, and Catheterization and Cardiovascular Interventions.

The update was partly triggered by the release of the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM) trial "and the concern that we might not have given a strong enough recommendation about CABG [vs PCI] in diabetes," he said.

FREEDOM, as heartwire previously reported, showed a significant drop in risk of death from any cause, nonfatal MI, or nonfatal stroke with CABG vs PCI in diabetic patients with multivessel CAD. The findings support prior but less conclusive studies pointing to better outcomes from CABG in such patients, such as BARI 2D . But the update states that "the strongest evidence supporting the use of CABG over PCI for patients with [type 2 diabetes] and multivessel CAD comes from a published meta-analysis of eight trials (including FREEDOM)."

Compared with earlier guideline, Fihn said, the update provides "a clearer recommendation that bypass surgery may be the optimal strategy in many patients who are diabetic with complex coronary disease."

Patients with stable IHD and type 2 diabetes should receive guideline-recommended medical therapy, and for those with symptoms that are still not adequately controlled, revascularization should be considered. The evidence points to the need for a heart-team approach early on, he said, "to get a consultation from the cardiologist and cardiovascular surgeon, before that patient is shuffled off" to the cath lab.

"Even though you've got a diabetic patient on the cath table and have determined the anatomy, just simply doing angioplasty at that point because it is convenient to do so may not be the best strategy for that patient," he noted. "Before a revascularization strategy is implemented, you really have to consider it from all points of view . . . and come up with what is optimal for a given patient."

Ad hoc PCI, Noninvasive Imaging, and Chelation

There was "concern among cardiologists that we hadn't adequately addressed [some worries] about diagnostic catheterization," according to Fihn. The update "makes the point that a catheterization in a stable patient in the absence of a noninvasive study should be a rare event," [and it] also has a new section that covers the use of invasive testing to diagnose CAD. In most patients with suspected stable IHD, "noninvasive stress testing for diagnosis and risk stratification is the appropriate initial study," it states.

Furthermore, invasive "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 [are] understood by the patient."

It may be appropriate to place multiple stents in a patient who does not want surgery or has a very high risk of surgical complications, but this might not be the best strategy for other patients. "The question really is, even in patients [with stable IHD] with a fairly substantial amount of ischemic burden, 'Does revascularization improve survival?' There's no evidence that PCI does this, at this point," he said.

The update also changes the recommendation for chelation therapy—which is not FDA-approved for preventing or treating CVD—from class 3 (no benefit) to class 2b (uncertain benefit), although a new abstract presented at a recent meeting again showed it didn't work in patients with stable IHD, he noted.

Finally, results from the ongoing International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial should help to better inform physicians. "The writing group strongly endorses the ISCHEMIA trial, which will provide contemporary, high-quality evidence about the optimal strategy for managing patients with non–left main [stable IHD] and moderate to severe ischemia," the update states. The trial, which has a projected enrollment of 8000 patients, is scheduled for completion in 2019.

Finn has no conflicts of interest. Disclosures for the coauthors are listed in the paper.


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