Unstable angina and NSTEMI: early management

Antiplatelet therapy

There was a strong indication from topic experts that the guideline needed to be updated. Experts stated that although no new evidence has been identified from literature searches, clinical practice indicates that ticagrelor and prasugrel are more potent and predictable antiplatelets than clopidogrel, but they also carry an increased risk of bleeding. As a result, cardiologists need to consider the predicted ischaemic risk and the estimated risk of bleeding. A further consideration is the duration of dual antiplatelet therapy. Experts stated that European Society of Cardiology and American Heart Association guidelines incorporated these issues into their revised guideline, which makes the prescription of antiplatelet therapy more individualised.

Decision: This review question should be updated.

Management strategies

Topic experts stated that there is an ongoing debate about whether angiography centres should have 24/7 capabilities for interventional procedures (angioplasty). They felt that this presents a substantive question about the structure of service provision. Some experts suggested that early angiography results in less radiation to the patient, less renal nephropathy, reduced tariff and shorter length of stay. They suggested that this is likely to have an impact on health economic modelling. Another topic expert suggested that patients with suspected non-ST elevation acute coronary syndromes are increasingly being offered coronary angiography (invasive strategy) and systematic use of risk stratification is not widely used. Furthermore, experts felt that evidence highlights that patients who are at highest risk of ischaemia benefit most from early angiography; however, data from registries suggests that cardiologists do not always select these patients

Decision: This review question should be updated.

New question: Drug-eluting stents

During the 6-year surveillance review of CG94, 1 new study on drug-eluting stents was identified; however, it was considered not to have an impact on guideline recommendations. A considerable amount of new evidence was identified from randomised controlled trials (RCTs) during the 2‑year surveillance review of CG167 (see below). The new evidence indicated that CG167 needed updating. Because both guidelines are due to be combined, it is proposed that this clinical question should be added to ensure that the combined guideline covers the use of drug-eluting stents for different types of acute coronary syndromes.

Decision: This review question should be added.

Culprit versus complete revascularisation

Currently, CG167 makes no recommendations on the use of multivessel PCI in people with STEMI and multivessel coronary disease.

One large RCT indicated some benefit of multivessel PCI whereas the remaining identified studies reported no significant differences between multivessel PCI and culprit-only PPCI in people with STEMI and multivessel coronary disease undergoing PPCI. In combination with the opinions of topic experts, the identified new evidence suggests that recommendations on the role of multivessel PCI could inform future clinical practice.

Decision: This review question should be updated.

New question: Drug-eluting stents

CG167 makes recommendations on PPCI using bare-metal stents but does not make any recommendations on PPCI using drug-eluting stents in patients with STEMI.

A considerable amount of evidence was identified that assessed the safety and efficacy of drug-eluting stents. The identified new evidence comparing drug-eluting stents and bare-metal stents was inconsistent: some studies indicated that drug-eluting stents were safer and more effective than bare-metal, whereas other studies reported no significant differences between the 2 types of stent. When different types of drug-eluting stents were compared against each other results tended to favour everolimus-eluting stents. Studies also reported that new stent designs conferred better outcomes than older designs. Topic experts highlighted that drug-eluting stent prices have decreased significantly since their initial introduction and bare-metal stents are generally no longer used for patients with STEMI. They felt that this may have cost implications on procurement.

It was considered that an extensive review of the evidence base on drug-eluting stents would ensure that their role in treatment of patients with STEMI is clearly defined.

Decision: This review question should be added.

New question: Antithrombin therapy

CG167 incorporates a recommendation from NICE's technology appraisal guidance on bivalirudin for the treatment of ST-segment-elevation myocardial infarction:

1.2.2 Bivalirudin in combination with aspirin and clopidogrel is recommended for the treatment of adults with STEMI undergoing primary PCI.

The new evidence was inconsistent in reporting the direction of the treatment effect of bivalirudin when used during PPCI. Some studies reported that bivalirudin was more effective than other antithrombins; some reported that it was less effective and others reported no difference in outcomes. Topic experts highlighted uncertainties about older studies and felt that new evidence suggests that heparin is superior to bivalirudin. The inconsistent evidence in addition to uncertainties outlined by topic experts indicates that this question should be updated to clarify the role bivalirudin and other antithrombins in patients with STEMI.

Decision: This review question should be added subject to agreement to update the technology appraisal on bivalirudin.

Unstable angina and NSTEMI: early management (CG94)

We found new evidence for CG94 that was not thought to have an effect on current recommendations. This evidence related to the efficacy and safety of adding a glycoprotein inhibitor (GPI; tirofiban, eptifibatide and abciximab) to aspirin and heparin therapy as adjunct therapy to patients with UA/ NSTEMI undergoing primary coronary intervention (PPCI).

We did not find any new evidence related to:

Myocardial infarction with ST-segment elevation: acute management (CG167)

We found new evidence related to CG167 that was not thought to have an effect on current recommendations. This evidence related to time to perfusion, pre-hospital versus in-hospital fibrinolysis, facilitated PPCI, radial versus femoral access, thrombus extraction during PPCI, hospital volumes of PPCI, rescue PCI and routine early angiography following fibrinolysis.

We did not find any new evidence related to cardiogenic shock and treatment of people who remain unconscious after a cardiac arrest.