Focused Update on SIHD Guideline Released

The ACC and the American Heart Association, along with several other partnering societies, have released an updated guideline for the diagnosis and management of patients with known or suspected stable ischemic heart disease (SIHD), including those with new-onset chest pain or stable pain syndromes.

The focused update, published July 28 in the Journal of the American College of Cardiology,  adds a new section specifically addressing the role of coronary angiography for the diagnosis of coronary artery disease (CAD) in patients with suspected SIHD, and includes several new or updated recommendations for treatment options, as well as CAD revascularization. The new section on coronary angiography includes four new recommendations, including a "Class I" recommendation for use "in patients with presumed SIHD who have unacceptable ischemic symptoms despite guideline-directed medical therapy and who are amenable to, and candidates for, coronary revascularization." Despite its certain "shortcomings and potential complications," the guideline writing group noted several areas where coronary angiography can be used to:

• Ascertain the cause of chest pain or anginal equivalent symptoms
• Define coronary anatomy in patients with ‘high-risk' noninvasive stress test findings as a requisite for revascularization
• Determine whether severe coronary artery disease may be the cause of depressed left ventricular ejection fraction
• Assess for possible ischemia-mediated ventricular arrhythmia
• Evaluate cardiovascular risk among certain recipient and donor candidates for solid-organ transplantation
• Assess the suitability for revascularization of patients with unacceptable ischemic symptoms (i.e., symptoms that are not controlled with medication and that limit activity or quality of life)

They also suggest that coronary angiography may be helpful if initial stress testing is inconclusive or has conflicting results.

In terms of SIHD treatment, the guideline writing group updated the recommendation for chelation therapy from "Class III: No Benefit" to "Class IIb" indicating the usefulness of chelation therapy is uncertain for reducing cardiovascular events in SIHD patients. "Although disodium ethylene diamine tetraacetic acid is approved by the U.S. Food and Drug Administration for specific indications, such as iron overload and lead poisoning, it is not approved for use in preventing or treating cardiovascular disease," they said. However, the writing group chose not to update the 2012 recommendation stating enhanced external counterpulsation (EECP) may be considered to help relieve refractory angina in SIHD patients. After re-examining the scientific evidence the group noted that, "in general, existing data, largely from uncontrolled studies, suggest a benefit from EECP among patients with angina refractory to other therapy." They went on to say that "additional data from well-designed randomized controlled trials are needed to better define the role of this therapeutic strategy in patients with SIHD."

CAD revascularization was another area of renewed focus for the writing group. The updated guideline includes a new "Class I" recommendation for a Heart Team approach to revascularization in patients with diabetes mellitus and complex multivessel CAD. In addition, the 2012 Guideline provision "probably" recommending coronary artery bypass graft surgery (CABG) over percutaneous coronary intervention (PCI) to improve survival in patients with multivessel CAD and diabetes mellitus, was updated to say "CABG is generally recommended in preference to PCI to improve survival in patients with diabetes mellitus and multivessel CAD for which revascularization is likely to improve survival … provided the patient is a good candidate for surgery." The writing group suggests going forward that future research may be facilitated by including a field in the ACC's CathPCI Registry and the Society of Thoracic Surgeons database to identify cases "turned down" for the alternative revascularization strategy.