ACC/AHA Release New Comprehensive ACS Guidelines

The American College of Cardiology (ACC) and the American Heart Association (AHA), in collaboration with other societies, released a full guideline on the management of patients with ACS on Thursday, more than a decade after separate STEMI and NSTE ACS guidelines were released.

The document, which incorporates fresh evidence as well as advice from other guidelines, “reflects something old, something new, something borrowed, and something talked through,” Sunil Rao, MD (NYU Langone Health, New York, NY), chair of the writing committee, told TCTMD. “It really does cover the gamut of recommendations from the time the patient is in the emergency department all the way through discharge.”

The last full guidelines for STEMI and NSTE ACS were published in 2013 and 2014, respectively, with a focused update on PCI in patients with STEMI released in 2015. A guideline dedicated to coronary revascularization was released in 2021, and recommendations from that document were adopted for the ACS guideline—published in the Journal of the American College of Cardiology and Circulation—in the absence of new data, Rao said.

This latest ACC/AHA guidance, developed in collaboration with the American College of Emergency Physicians, the National Association of EMS Physicians, and the Society for Cardiovascular Angiography and Interventions, brings STEMI and NSTEMI patients into one document.

“There’s a lot of similarities in the final treatment of these patients, but the initial treatment in terms of reperfusion or not will depend on what their presentation is,” Jacqueline Tamis-Holland, MD (Cleveland Clinic, OH), an author of the new guidelines, told TCTMD.

By grouping STEMI and NSTEMI together, she added, “I’m really hoping that it’s going to make everybody much more comfortable because we had clinical trials that came out, but the guidelines were so out of date. I’m really hoping it’ll just put people on a more contemporary level now.”

Procedural Considerations

Among the new or updated guidance in the document are class 1 recommendations for complete revascularization including the nonculprit arteries for both STEMI and NSTE ACS. Although the 2021 revascularization guidelines recommended doing so in a staged fashion for patients with STEMI, the current document gives a “slight preference” for completing it in one procedure, Rao said.

Use of intracoronary imaging—IVUS or OCT—during PCI also has been given a class 1 recommendation, up from class 2a in the revascularization guidelines, in response to recent RCT data showing improvements in stent-related and clinical outcomes. The guidance applies to patients with left main or complex lesions.

What we all hope for is just for patient outcomes to get better. Sunil Rao

Another noteworthy addition is a class 2a recommendation stating that use of a microaxial intravascular flow pump—like the Impella CP device (Abiomed/Johnson & Johnson MedTech)—is reasonable to reduce death in selected patients with STEMI and severe or refractory cardiogenic shock.

That advice is based on the positive results of the DanGer Shock trial, and there had been some debate about whether the study would support a class 1 or 2a recommendation. The decision, Rao said, came down to a balance of the risks and benefits. “There is a risk associated with these large-bore devices—that was very clearly laid out in the DanGer Shock trial as it relates to peripheral arterial complications and so forth,” he explained. “It’s one trial. It’s a huge benefit. But again, when you try to balance that benefit and the risk, the entire writing committee felt that it was better to land on the 2a recommendation rather than the class 1.”

Transfusion Strategies, Antiplatelet Therapy, and Secondary Prevention

Rao also highlighted a new recommendation based on the MINT trial, which he participated in. The study missed its primary endpoint but suggested that liberal use of red blood cell transfusions in patients with acute MI and anemia may improve some outcomes, including cardiac death. The new guideline contains a class 2b recommendation stating that giving transfusions to maintain a hemoglobin of at least 10 g/dL may be reasonable in patients with acute or chronic anemia who aren’t actively bleeding.

Much of the guidance around use of antiplatelet therapy is carried over from prior documents, and there is still a class 1 recommendation to use dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor for at least 12 months as the default in patients with low bleeding risk.

There are several recommendations covering strategies to reduce bleeding risk in patients who undergo PCI. These include use of a proton pump inhibitor in patients at risk for GI bleeding; transitioning to ticagrelor monotherapy a month or more after the procedure in patients who have tolerated DAPT with ticagrelor and aspirin; and discontinuing aspirin 1 to 4 weeks after PCI in patients who require long-term anticoagulation and continuing with a P2Y12 inhibitor (preferably clopidogrel) plus the anticoagulant.

The new document offers additional secondary prevention recommendations, such as guidance around lipid management. Here, the writing group gave a class 1 recommendation to doing a fasting lipid panel 4 to 8 weeks after initiation of dose adjustment of lipid-lowering therapy to assess response and whether additional medications might be needed.

The authors recommend that patients who have an LDL cholesterol level of 70 mg/dL or more despite taking maximally tolerated statin therapy should add a nonstatin, lipid-lowering agent like ezetimibe, evolocumab, alirocumab, inclisiran, or bempedoic acid to further reduce the risk of MACE (class 1). And it’s reasonable to add a nonstatin therapy if the LDL-cholesterol level is 55 to 69 mg/dL (class 2a).

Referral to outpatient cardiac rehabilitation prior to discharge gets a class I recommendation as a means for reducing death, MI, and hospital readmissions and for improving functional status and quality of life; home-based programs are a reasonable alternative (class 2a).

Overall, Rao said, the document “is really the best synthesis of the best evidence that’s out there. It’s gone through a very rigorous process with the writing committee [and] several rounds of peer review. So we’re really proud of this document.”

And ultimately, “what we all hope for is just for patient outcomes to get better,” he added, noting that prior research has shown that adherence to guideline recommendations is associated with improved outcomes in patients with ACS. “I think we still all believe that to be true. And so as the guidelines writing committee chair, what I really hope for is to see widespread implementation, particularly of our class 1 recommendations, so that patients continue to do better. And I also hope that we can de-implement our class 3 recommendations. Because that’s really where I think the evidence is very clear that you should do something or you should not do something.”

As in prior documents, there are class 3 recommendations advising against the use of manual aspiration thrombectomy during primary PCI in patients with STEMI due to lack of benefit, against routine PCI of non-infarct-related arteries at the time of index PCI in patients with ACS complicated by cardiogenic shock due to increased risks of death and renal failure, and against the routine use of glycoprotein IIb/IIIa inhibitors due to the lack of ischemic benefit and a greater risk of bleeding, among others.