New ESC ACS Guideline Combines STEMI and NSTE-ACS

September 08, 2023

New European Society of Cardiology (ESC) guidelines on the management of acute coronary syndromes (ACS) have for the first time combined ST-elevation MI (STEMI), non-ST-elevation MI (NSTEMI), and unstable angina into the same set of recommendations.

The new guideline was released at the recent European Society of Cardiology (ESC) Congress 2023, held in Amsterdam, the Netherlands, and was published online in the European Heart Journal.

"We found that it was realized by the cardiology community that patients with STEMI, NSTEMI, or unstable angina represent a spectrum," the chair of the guideline task force, Robert Byrne, MD, chair of cardiovascular research at the RCSI University of Medicine and Health Sciences, Dublin, Ireland, explained to | Medscape Cardiology. "After the initial triage and management decisions, then most of the rest of the care follows a common pathway so it would make sense to consider everything in one guideline."

Byrne noted that for all patients with a suspected ACS, the guideline recommendation is to administer an ECG within 10 minutes of presentation. The time is critical particularly for those with an occluded epicardial vessel. If there are features on the ECG that suggest an acutely occluded epicardial vessel, then the patient needs immediate angiography or primary angioplasty.

"The 10-minute guidance has been maintained from previous guidelines, but the nuance in the new guideline is that typically when we think of an occluded epicardial vessel we think of ST-elevation on the ECG," Byrne said. "While this captures most occluded epicardial vessels, it doesn't capture all of them. So, we have provided some guidance on alternative ECG patterns which might be indicative of an acute occlusion of the epicardial vessel and should be dealt with in the same way as an ST-elevation MI. This is a new concept."

This situation could arise when a patient has an occluded circumflex artery and the regular ECG may not show ST elevation but the patient has ongoing pain, he noted. "There are additional ECG leads that can be looked at that might identify patients who need an immediate invasive strategy.

"This is one more reason why all ACS patients should be considered as part of one spectrum, and while the ECG gives us important information, it is not the only thing to consider. Dividing the conditions up as to whether a patient has ST elevation or not does not always make pathophysiological sense," he added.

Byrne noted that the new guidelines have tried to reach a wider stakeholder group that includes emergency doctors, internal medicine physicians, general practitioners, surgeons, as well as cardiologists. The document includes animations in an effort to increase the reach of the guidelines to non-cardiology stakeholders, and for the first time, the task force included a patient representative.

"As part of this strategy, we have put more structure in to emphasize the importance that at first contact, we already want to be thinking of antithrombotic therapy and whether the patient needs urgent transfer to the nearest cath lab. We also want to be thinking straight away about preventing the next heart attack by implementing strong secondary prevention measures," he commented.

Byrne highlighted a few changes to individual recommendations in the new guidelines.

Invasive Management In NSTE-ACS

He pointed out that a small change has been made in the advice on invasive management for patients with non-ST-elevation ACS.

Byrne explained that patients with ST elevation should be sent immediately to a cath lab for PCI. If this is not possible within 120 minutes, then the patient should receive thrombolysis. This recommendation is the same as in previous guidelines.

He added, however, that there is some novelty in recommendations for patients who don't have ST elevation but do have a positive troponin. For this group, previous guidelines gave a Class I recommendation that all such patients undergo an angiogram within the first 24 hours. However, an additional meta-analysis that was published in 2022 showed that the evidence for triaging all patients to the cath lab within 24 hours is somewhat limited, Byrne noted.

"At the end of the day, the task force felt that a Class I recommendation to get all patients to the cath lab within 24 hours was too strong and couldn't be sustained, so it has been downgraded to a Class IIa recommendation, which we thought was more appropriate," he said.

"So, while all patients should still have an angiogram during the hospital admission, if they are hig- risk ACS, the imperative to get everyone to the cath lab within 24 hours ― which many of our colleagues were finding difficult to achieve ― does not seem to be backed up by the evidence," he added.

Antithrombotic Therapy

On administration of antithrombotics, the guidelines emphasize that at the time of initial diagnosis, all patients should receive antithrombotic therapy, usually aspirin and a parenteral antithrombotic, such as heparin, enoxaparin, bivalirudin, or fondaparinux. Byrne noted that the guidelines have a new algorithm as to which of these antithrombotics to give, depending on the clinical presentation of the patient.

On the use of upfront P2Y12 inhibitors, Byrne said the new guidelines only give a weak recommendation for this.

"Giving a P2Y12-inhibitor up front does not have a strong evidence base, and it's not unreasonable to wait, do the angiogram, see where you are, and then start the P2Y12 inhibitor. This is something that's not widely done in clinical practice," he commented.

"The last 2020 guideline gave a Class III recommendation for upfront P2Y12 inhibitor therapy for ACS patients who do not have STEMI. We've generally maintained that with the introduction of the exception that if you are in a healthcare system where there is a long wait to get to the cath lab ― 5 ,6 or 7 days ― then its reasonable to make an exception and give a P2Y12 inhibitor, but otherwise we've sustained the Class III recommendation," he noted.

Also, for patients who have STEMI, there is a new Class IIb recommendation that upfront P2Y12 inhibitors may be considered.

"This is also rather a weak recommendation. There isn't a strong rationale to give a P2Y12 inhibitor it in ST elevation either. It's also reasonable to wait," he added.

Don't Rush Cardiac Arrest Patients to the Cath Lab

Another update in the guidelines involves the management of patients with cardiac arrest who have been resuscitated. Byrne explained that these patients would all receive an immediate ECG, and if it is found that they have ST elevation, they would be sent immediately to the cath lab. But a series of randomized trials has suggested that for patients who don't have ST elevation, it is not necessary to rush these patients to the cath lab.

"We've given a Class III recommendation for this, saying it may be better to stabilize the patients first in the ICU. This is in recognition that a large proportion of these patients turn out not to have an MI. They have had a cardiac arrest for another reason," Byrne noted. "Moving them to the cath lab when they are still unstable could be harming these patients rather than helping them."

Revascularization for Multivessel Disease

Byrne notes that revascularization remains a critical element in the care for patients with STEMI, and there is a new recommendation in this area for patients with multivessel disease.

"Up to half of patients presenting with STEMI have multivessel disease, and we now have five randomized trials to say that these patients should have complete revascularization rather than just the culprit vessel. There is a new Class I recommendation for this," he said.

However, the optimal timing of revascularization (immediate vs staged) has still not been investigated in adequately sized randomized trials, and no recommendation has been made on this, the task force notes.

Byrne commented: "If you want to do everything in one go, that's fine, but it's also okay to do culprit lesion first and then the other vessels at a later date within 45 days. This might depend on individual circumstances. For example, if there are complex lesions or the vessels are heavily calcified, then it may be best to get the culprit lesion fixed first and let the patient recover, then bring them back in for the rest."

He pointed out that the results of the MULTISTARS trial, which were not available when the task force was formulating the guidelines, were reported at the ESC congress and confirmed their recommendation.


On the duration of dual antiplatelet therapy (DAPT) after PCI, the new guidelines have largely retained prior recommendations for a default strategy of 12 months for the combination of aspirin and a P2Y12 inhibitor.

"This was the subject of some discussion, as there have been several trials now looking at shorter durations of DAPT and deescalating after a few months to just one of these treatments. And while there is a rationale to do this, we think it's best to be kept as an alternative strategy rather than the default strategy," Byrne said.

He explained that the trials of DAPT deescalation tended to enroll lower-risk patients, which reduced the generalizability of the results.

Most of the trials only randomly assigned patients to shorter durations of DAPT when they were event-free for some period, she said.

"This is a dynamic decision-making process and reflects the real world to some extent. We think it is best to recommend the standard aspirin and a P2Y12 inhibitor for the 12- month duration, but at 3 months, if the patient is doing well but you may be worried about bleeding risk, then you could decide to deescalate to single antiplatelet therapy," she noted. "So, there is Class IIa recommendation that this can be considered, but it is not recommended as the default position."

Polypill for Secondary Prevention

Another innovation in the new guidelines is a new Class IIa recommendation for prescription of a polypill containing secondary prevention medications for patients on discharge from hospital.

This recommendation follows a trial that showed that the use of such a polypill helps patients be more adherent to the therapies prescribed.

Byrne explains that such a polypill may contain aspirin, an ACE inhibitor, and a statin. Several varieties are available in most European countries, but they are not widely used.

On secondary prevention, he stressed, "Prevention of the next heart attack starts before the patient leaves hospital. It is important to make sure the patient has the right medication on board, including a high-dose, high-intensity statin, and has been referred to a cardiac rehabilitation program. These are largely maintained recommendations from previous guidelines, but they are very important."

European Society of Cardiology (ESC) Congress 2023: Presented August 25, 2023.

Eur Heart J. Published online August 25, 2023. Full text

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