Acute Coronary Syndrome

The 2025 ACC/AHA/ACEP/NAEMSP/SCAI guideline addresses presumed type 1 ACS: unstable angina, NSTEMI, and STEMI resulting from plaque disruption with coronary thrombosis. Unstable angina reflects transient ischemia without significant troponin-detected myonecrosis; NSTEMI requires myocardial injury with ischemic evidence; STEMI generally reflects acute transmural ischemia from complete coronary occlusion. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Obtain and interpret a 12-lead ECG within 10 minutes of first medical contact or hospital presentation. Persistent ST-segment elevation should trigger STEMI reperfusion pathways without waiting for troponin. In NSTE-ACS, ECG findings may include dynamic ST depression, T-wave inversion, transient ST elevation, nonspecific changes, or a normal tracing. Repeat ECGs when symptoms continue, clinical suspicion remains high, or the patient deteriorates. Isolated anterior ST depression in V1-V3 should prompt posterior leads V7-V9 to assess for posterior STEMI. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Measure cTn promptly, preferably hs-cTn. With initially nondiagnostic results, repeat hs-cTn at 1 to 2 hours or conventional cTn at 3 to 6 hours. Acute MI requires a rise and/or fall with at least one value above the assay-specific 99th-percentile upper reference limit plus clinical evidence of ischemia. Troponin elevation alone does not establish type 1 MI; interpret it against symptoms, ECG, and competing causes of myocardial injury. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Give non-enteric-coated aspirin 162 to 325 mg orally, chewed when possible, followed by 75 to 100 mg daily. Aspirin is recommended across ACS phenotypes unless an absolute contraindication exists; for reported hypersensitivity, desensitization is preferred when feasible, while a loading dose of a P2Y12 inhibitor should be given if aspirin cannot be taken. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Add an oral P2Y12 inhibitor. In ACS undergoing PCI, prasugrel or ticagrelor is recommended over clopidogrel to reduce MACE and stent thrombosis. In NSTE-ACS managed without planned invasive assessment, ticagrelor is recommended; clopidogrel is the alternative when ticagrelor or prasugrel is unavailable, contraindicated, or intolerable. Prasugrel is contraindicated with prior stroke or TIA. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Use parenteral anticoagulation for presumed ACS. UFH is useful in NSTE-ACS and PCI. Enoxaparin or fondaparinux are alternatives when early invasive management is not planned; do not use fondaparinux as the sole PCI anticoagulant because of catheter thrombosis risk. For STEMI PCI, bivalirudin is an alternative to UFH; for fibrinolysis-treated STEMI, continue parenteral anticoagulation through hospitalization for up to 8 days or until revascularization. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

For STEMI presenting within 12 hours, perform primary PCI when first-medical-contact-to-device activation can occur within 90 minutes, or within 120 minutes for patients requiring transfer. EMS transport to a PCI-capable hospital, prehospital ECG transmission, and catheterization laboratory activation are recommended system strategies. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

When expected first-medical-contact-to-device time exceeds 120 minutes and symptom onset is under 12 hours, administer fibrinolytic therapy if no contraindication exists, then transfer immediately to a PCI-capable center. Patients with failed reperfusion require immediate angiography and rescue PCI; otherwise, perform early angiography with intent to PCI within 2 to 24 hours after fibrinolysis. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Primary PCI remains indicated regardless of symptom duration in ACS with cardiogenic shock or hemodynamic instability. In stable patients with STEMI and an occluded infarct-related artery more than 24 hours after onset without ongoing ischemia, severe heart failure, or life-threatening arrhythmia, routine PCI has no demonstrated benefit. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

For intermediate- or high-risk NSTE-ACS patients who are appropriate candidates for revascularization, perform an invasive approach during hospitalization. For low-risk patients, either routine invasive or selective invasive management with additional risk stratification is recommended. Patients in whom ACS remains uncertain and biomarkers are normal may undergo stress testing or coronary CT angiography before discharge to clarify need for angiography. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Perform immediate invasive evaluation for refractory or recurrent angina despite medical therapy, hemodynamic or electrical instability, acute pulmonary edema or heart failure, worsening mitral regurgitation, or sustained ventricular arrhythmia. In high-risk NSTE-ACS, early angiography within 24 hours is reasonable; a GRACE score above 140, advancing troponin pattern, new ST depression, diabetes, age over 75 years, or elevated biomarkers support earlier evaluation. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Relative reasons to reconsider a routine invasive strategy include severe thrombocytopenia, high bleeding risk on DAPT, advanced kidney disease not on dialysis, acute renal failure, limited life expectancy, advanced dementia, anatomy already known to preclude PCI/CABG, and patient preference. These are risk-benefit considerations, not automatic exclusions. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

For ACS PCI, radial access is preferred over femoral access. In complex lesions or left main intervention, use IVUS or OCT to guide coronary stent implantation and reduce ischemic events. Routine manual aspiration thrombectomy before primary PCI should not be performed because it has not improved clinical outcomes; reserve it for bailout treatment of persistent thrombus or no-reflow. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

In hemodynamically stable STEMI with multivessel disease, complete revascularization of significantly stenosed nonculprit arteries is recommended after successful culprit-vessel PCI to reduce death or MI and improve angina-related quality of life. PCI may be staged or, in selected low-complexity disease, performed during the index procedure. Patients with left main disease, complex multivessel disease, diabetes with LAD involvement, or severe LV dysfunction may be better served by CABG after Heart Team assessment. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

In stable NSTE-ACS with multivessel disease and no left main stenosis, complete PCI of significant nonculprit lesions at the index procedure or as a staged intervention is recommended when CABG is not intended. Physiologic assessment of nonculprit lesions may guide revascularization. In cardiogenic shock, routine nonculprit PCI at the index procedure increases death or kidney-failure risk and should not be performed. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

For ACS patients without high bleeding risk, continue DAPT with aspirin and an oral P2Y12 inhibitor for at least 12 months. In patients who tolerate ticagrelor-based DAPT, transition to ticagrelor monotherapy at least 1 month after PCI is useful for bleeding reduction. In high-bleeding-risk PCI patients, transition to single antiplatelet therapy after 1 month may be reasonable; switching from ticagrelor or prasugrel to clopidogrel after 1 month may also reduce bleeding risk. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

If long-term oral anticoagulation is required, discontinue aspirin after 1 to 4 weeks of triple therapy and continue an oral anticoagulant plus a P2Y12 inhibitor, preferably clopidogrel. Prescribe a proton pump inhibitor for patients at elevated GI bleeding risk receiving DAPT, anticoagulation, or both. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

Initiate or continue high-intensity statin therapy for all ACS patients unless contraindicated. In patients already receiving maximally tolerated statin therapy, add a nonstatin agent if LDL-C is 70 mg/dL or greater; adding nonstatin therapy is reasonable at LDL-C 55 to 69 mg/dL. Concurrent ezetimibe plus maximally tolerated statin may be considered during the index ACS admission. AHA JournalsAHA Journals2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines