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2025 ACC/AHA Acute Coronary Syndromes Guidelines

Clinical Quick Reference — Management of STEMI, NSTE-ACS, and Cardiogenic Shock

Published: Circulation (2025) | Volume 151, e771–e862
Societies: ACC, AHA, ACEP, NAEMSP, SCAI
DOI: 10.1161/CIR.0000000000001309
View Full Guideline PDF

What's New in 2025

This comprehensive guideline retires and replaces the 2013 STEMI and 2014 NSTE-ACS Guidelines, incorporating evidence through April 2024:

Topic2013–20142025 Update
DAPT DurationStandard 12 months12 months standard; shortened (1–3 months) or extended (30+ months) by DAPT Score & ARC-HBR
P2Y12 SelectionClopidogrel acceptablePrasugrel/Ticagrelor preferred; clopidogrel for high-bleed-risk only
AnticoagulationUFH standardUFH, bivalirudin (with 2–4h post-PCI infusion), or enoxaparin; NO fondaparinux for PCI
OxygenRoutine supplementalOnly for SpO₂ <90%; NO routine oxygen (Class 3: No Benefit)
StatinHigh-intensity; LDL <70High-intensity + nonstatin add-ons (PCSK9i, ezetimibe, bempedoic acid) if LDL ≥70
Cardiogenic ShockVariable multivessel approachCulprit-only PCI recommended; NO multivessel in shock (CULPRIT-SHOCK)

Initial Evaluation & Risk Stratification

Diagnostic Approach

ACS classification: STEMI (ST elevation ≥1 mm limb or ≥2 mm precordial + troponin/LBBB); NSTE-ACS (ST depression, T-wave changes, or normal ECG + elevated troponin [NSTEMI] or normal [unstable angina]).

High-Sensitivity Troponin (hs-cTn):
  • 1 Obtain at presentation; reassess within 1–3 hours
  • Single negative hs-cTn at <2 hours does NOT exclude ACS in high-risk patients
  • 0/1 hour serial sampling improves early rule-out in low-risk

Risk Stratification Tools

ScoreUseKey ComponentsInterpretation
GRACENSTE-ACS & STEMIAge, HR, SBP, Killip, Cr, troponin, STLow: <109; Intermediate: 109–140; High: >140
HEARTED chest pain rule-outHistory, ECG, Age, Risk factors, TroponinLow: 0–3; Intermediate: 4–6; High: 7–10
TIMINSTE-ACSAge ≥65, ≥3 RF, prior CAD, ASA, severe angina, ECG changes, troponinLow: 0–2; Intermediate: 3–4; High: 5–7
Pearl: Early hs-cTn with risk stratification reduces ED LOS while maintaining safety in low-risk patients.

STEMI Management: Reperfusion Strategy

Door-to-Balloon Targets

ScenarioTarget TimeClass
PCI-capable, PPCI≤90 min from FMC1
Non-PCI, fibrinolytic≤30 min from FMC1
Rescue PCI (failed fibrinolysis)Within 3–24 hours1

Reperfusion Algorithm

STEMI Reperfusion Decision Tree

Step 1: Confirm STEMI on ECG; activate EMS/ED protocol
Step 2: Is on-site PCI available within 90 min?
YES: PPCI; activate cath lab; DAPT + anticoagulation; goal door-to-balloon ≤90 min
NO: Fibrinolytic within 30 min; consider transfer if rescue needed; continue DAPT + anticoagulation
Step 3: Multivessel CAD detected?
  • Stable: Culprit + staged PCI of significant lesions
  • Shock: Culprit-only PCI (NO multivessel; increases mortality)

Fibrinolytic Therapy (Non-PCI Centers)

Indications: STEMI at non-PCI-capable hospital, within 12 hours of symptom onset.

AgentDosingNotes
Alteplase (tPA)15 mg bolus, then 0.75 mg/kg/30 min (max 50), then 0.5 mg/kg/60 min (max 35)Weight-based; preferred
Tenecteplase (TNK)30–50 mg single IV bolus (weight-based)More convenient; similar efficacy
Pearl: Prehospital ECG by EMS + direct cath lab notification improves door-to-balloon times. Transfer for PCI is preferred over fibrinolysis if anticipated total delay <90 minutes.

NSTE-ACS: Invasive vs. Conservative Strategy

Risk-Based Approach

NSTE-ACS Strategy Selection

Step 1: Assess ischemic risk (GRACE, TIMI, or HEART); troponin status; ECG changes
HIGH/INTERMEDIATE: 1 Routine invasive (angiography ≤24 h high-risk, 24–72 h intermediate); proceed to PCI if suitable
LOW: 1 Selective invasive or conservative; further risk stratification (serial troponin, stress, CAC) before deciding
Step 2: Check contraindications (severe renal failure, bleeding, etc.); adjust strategy if needed

Timing of Angiography

Risk CategoryTime WindowClass
Very High (shock, ongoing ischemia)Immediate (<2 h)1
High (elevated troponin, dynamic ST, unstable)≤24 hours1
Intermediate (multiple RF, borderline troponin)24–72 hours2a
Low (single episode, normal troponin)Outpatient/deferred2b

Antiplatelet Therapy

Aspirin

1 Loading: 162–325 mg chewed at presentation (faster onset). Maintenance: 75–100 mg daily low-dose preferred (reduced bleeding without loss of benefit).

P2Y12 Inhibitor Selection

P2Y12 Inhibitor Choice Algorithm

Preferred: Prasugrel 60 mg load, 5–10 mg daily; OR Ticagrelor 180 mg load, 90 mg BID
  • Both reduce MACE & stent thrombosis vs. clopidogrel (TRITON-TIMI 38, PLATO)
Prasugrel Contraindications:
  • Prior stroke/TIA (net harm); weight <60 kg (caution); age ≥75 (use 5 mg with caution)
Alternative: Clopidogrel 600 mg load, 75 mg daily (if prasugrel/ticagrelor contraindicated or high-bleed-risk)
  • Less potent; acceptable for high-bleeding-risk patients
AgentLoading (ACS)MaintenanceClassKey Notes
Aspirin162–325 mg (chewed)75–100 mg daily1Foundational; low cost
Prasugrel60 mg5–10 mg*121% ↓ MACE; avoid stroke Hx; ↑ bleeding
Ticagrelor180 mg90 mg BID116% ↓ MACE; dyspnea ~10–15%; ↑ bradycardia
Clopidogrel300–600 mg75 mg daily1If prasugrel/ticagrelor contraindicated; less potent

*Prasugrel 5 mg if age ≥75 or weight <60 kg.

Pitfall: Delaying P2Y12 load waiting for angiography in STEMI. Load immediately on presentation to reduce periprocedural thrombosis.

Parenteral Anticoagulation

1 Mandatory for all ACS at presentation to reduce thrombotic events.

AgentLoading / DosingPCI DosingKey Notes
UFH60 IU/kg bolus (max 4000)70–100 U/kg to ACT 250–300 sStandard; reversible with protamine; HIT risk (rare)
Bivalirudin0.75 mg/kg bolus1.75 mg/kg/h during PCI + 2–4h post-PCI full-dose infusion (STEMI)1 STEMI PPCI: ↓ bleeding & mortality; direct thrombin inhibitor; no HIT
Enoxaparin1 mg/kg SC Q12h; IV 0.5–0.75 mg/kgAdjust based on timing; adjust if CrCl <302a Alternative to UFH; ↓ MACE in STEMI PPCI (ATOLL)
Fondaparinux2.5 mg IV or SC dailyCONTRAINDICATED (catheter thrombosis 0.9%)Factor Xa inhibitor; DO NOT use for PCI; acceptable for fibrinolytic support
Pearl: Bivalirudin with 2–4h post-PCI infusion at full dose (1.75 mg/kg/h) is superior to UFH in STEMI PPCI for mortality and BARC 3–5 bleeding (BRIGHT-4 trial).

Dual Antiplatelet Therapy (DAPT) Duration After Discharge

Default Strategy: 12 Months

1 Standard DAPT is 12 months of aspirin + P2Y12 inhibitor unless high-bleed/ischemic risk warrants adjustment.

Shortened DAPT (1–3 Months)

2b Consider if high bleeding risk by ARC-HBR (age >75, low weight, renal disease, bleeding Hx).
  • P2Y12 Monotherapy Option: Transition to ticagrelor 90 mg BID at 1–3 months, discontinue aspirin; continue P2Y12 for 12 months total
  • Evidence: STOPDAPT-2 ACS trial showed 1-month DAPT was noninferior to 12-month in high-bleed-risk

Extended DAPT (30+ Months)

2b Consider if high ischemic risk by DAPT Score (age, diabetes, prior MI, reduced EF) AND low bleeding risk.
  • Trade-off: ↓ ischemic events but ↑ bleeding risk
ScenarioDAPT DurationClassRisk Tool
Standard Risk12 months1Clinical judgment
High Bleeding Risk1–3 months, then P2Y12 monotherapy to 12 mo2bARC-HBR
High Ischemic Risk12–30 months2bDAPT Score
Pitfall: Discontinuing P2Y12 inhibitor first in high-bleed-risk patients. Discontinue aspirin instead; stent thrombosis risk ↑ significantly if P2Y12 dropped.

Secondary Prevention: Lipid Management

Statin Intensity

1 High-intensity statin mandatory for all ACS, regardless of baseline LDL-C.

IntensityAgents & DosesLDL-C Reduction (%)
High-IntensityAtorvastatin 40–80 mg; Rosuvastatin 20–40 mg≥50%
Moderate-IntensityAtorvastatin 10–20 mg; Rosuvastatin 5–10 mg; Simvastatin 20–40 mg; Pravastatin 40–80 mg30–49%

LDL-C Targets & Nonstatin Add-On

Lipid Management Algorithm

Step 1: Initiate high-intensity statin immediately (don't delay for lipid panel; LDL drops 24h post-MI)
Step 2: Assess LDL-C at 4–12 weeks post-discharge. Goal: <70 mg/dL (some prefer <55 early post-ACS)
LDL-C ≥70 on statin: Add nonstatin: ezetimibe 10 mg (↓15–25%), OR PCSK9i evolocumab/alirocumab (↓~60%), OR bempedoic acid 120 mg (↓~20%), OR inclisiran (↓~50%; Q6 months)
LDL-C 55–69: 2a Consider nonstatin add-on for additional benefit
AgentLDL-C ReductionDosingAdverse Effects
Ezetimibe15–25% (with statin)10 mg dailyLFT abnormalities (rare); myalgia
PCSK9 mAb (Evolocumab, Alirocumab)~60%140–420 mg SC Q2 weeks or 300–600 mg Q4 weeksInjection site reactions; neurocognitive concerns (disputed)
Bempedoic Acid~20%120 mg daily↑ Uric acid (gout); gallstones; LFT elevations; **avoid with simvastatin >20 mg or pravastatin >40 mg**
Inclisiran~50%284 mg SC at 0, 3, 6 months, then Q6 monthsInjection site reactions; outcomes trials ongoing
Pearl: Ezetimibe + statin combination improves LDL-C reduction vs. statin monotherapy. Initiate concurrently at discharge if LDL-C ≥70 mg/dL for additive benefit.

Secondary Prevention: Beyond Lipids

Beta-Blockers

1 Initiate oral beta-blocker within 24 hours post-ACS (unless contraindicated: hypotension, bradycardia, shock, decompensated HF).
  • Target HR: 50–60 bpm at rest
  • Common agents: Metoprolol 25–50 mg BID, Atenolol 25–50 mg daily, Carvedilol 3.125–12.5 mg BID
  • Duration: Minimum 3 years; lifelong if LVEF ≤40% or HF

ACE Inhibitors / ARBs

1 ACE inhibitor recommended for all ACS (especially LVEF ≤40%, HTN, diabetes, CKD).
  • Start: Within 24 hours if hemodynamically stable (SBP ≥90 mmHg)
  • Common agents: Lisinopril 5–10 mg daily, Enalapril 5–10 mg BID, Ramipril 2.5–10 mg daily
  • ARB alternative: Losartan 25–100 mg daily, Valsartan 80–160 mg daily (if ACE inhibitor intolerant)
  • Monitor K+ and Cr (especially if CKD)

Lifestyle & Cardiac Rehabilitation

Post-Discharge Medications Summary

Drug ClassIndicationDurationClass
AspirinAll ACSLifelong (or 1–4 weeks if on anticoagulation)1
P2Y12 InhibitorAll ACS12 months (shortened or extended by risk)1
High-Intensity StatinAll ACSLifelong1
Beta-BlockerAll ACS; essential if LVEF ≤40%Minimum 3 years; lifelong if EF ≤40% or HF1
ACE-I / ARBAll ACS; especially EF ≤40%, DM, HTN, CKDLifelong1
Nonstatin (if needed)LDL-C ≥70 mg/dL on statinLifelong1

Special Populations

Elderly (Age >75 Years)

Chronic Kidney Disease (CKD)

Diabetes Mellitus

Prior CABG

ACS Complications (Brief Overview)

Mechanical Complications

Electrical Complications

LV Thrombus

Pearl: Post-MI HF (Killip class 3–4, pulmonary edema) may require ICU diuresis, vasopressor support, and mechanical support. 1 Early revascularization + beta-blocker/ACE-I improve outcomes.

Clinical Pearls: Do's & Don'ts

✓ DO

  • Activate PPCI for confirmed STEMI within 90 min of FMC; prehospital ECG + direct cath lab communication improves times
  • Load DAPT immediately on arrival (aspirin + P2Y12 inhibitor); don't delay for angiography
  • Continue anticoagulation until revascularization; premature discontinuation ↑ reinfarction risk
  • Use bivalirudin with post-PCI infusion (2–4h at full dose) in STEMI PPCI for mortality/bleeding benefit
  • Use prasugrel or ticagrelor preferentially in ACS with PCI vs. clopidogrel (unless contraindicated)
  • Start high-intensity statin immediately (don't wait for lipid panel; LDL drops 24h post-MI)
  • Initiate beta-blocker + ACE-I within 24 hours if hemodynamically stable (mortality reduction)
  • Use ARC-HBR & DAPT Score to individualize DAPT duration (shortened or extended)
  • Refer to cardiac rehabilitation post-discharge (↓ MACE by ~25%)
  • Assess bleeding risk using ARC-HBR in all ACS patients

✗ DON'T

  • Don't delay reperfusion for noninvasive testing in STEMI; time is myocardium
  • Don't omit anticoagulation at ACS diagnosis; all patients require UFH, enoxaparin, bivalirudin, or fondaparinux (upstream)
  • Don't use fondaparinux alone for PCI; catheter thrombosis risk is prohibitive. If used upstream, add UFH bolus before PCI
  • Don't use prasugrel in stroke/TIA history; net harm (bleeding without ischemic benefit)
  • Don't discontinue P2Y12 inhibitor first if shortening DAPT in high-bleed-risk; discontinue aspirin instead (keep P2Y12 inhibitor for 12 months minimum)
  • Don't delay lipid-lowering therapy; start statin immediately; triage nonstatin add-ons later
  • Don't use multivessel PCI in cardiogenic shock; culprit-only approach standard (CULPRIT-SHOCK); worse outcomes with multivessel
  • Don't give routine supplemental oxygen to patients with SpO₂ ≥90%; no MACE benefit, possible harm
  • Don't perform routine GP IIb/IIIa inhibitor pretreatment; use only for adjunctive rescue (large thrombus/no-reflow) during PCI
  • Don't extend DAPT beyond 12 months routinely without assessing ischemic & bleeding risk

Related Risk Calculators & Tools

Evidence-based calculators help risk-stratify ACS patients, guide antiplatelet/anticoagulation therapy, and optimize secondary prevention:

GRACE Risk Score

Predicts in-hospital and 6-month mortality in ACS using age, HR, BP, Killip, troponin, Cr, ST changes.

GRACE In-Hospital

Simplified version for rapid bedside assessment of in-hospital mortality risk in ACS.

HEART Score

ED-friendly chest pain risk stratification; identifies low-risk patients safe for early discharge without serial troponin.

TIMI UA/NSTEMI Score

7-point risk score for NSTE-ACS mortality and MACE; guides invasive timing decision.

DAPT Score

Calculates ischemic vs. bleeding risk to guide DAPT duration (shortened, 12 months, or extended).

ARC-HBR (High Bleeding Risk)

Identifies patients at high bleeding risk on DAPT; guides P2Y12 inhibitor choice and DAPT duration.

PRECISE-DAPT Score

Alternative bleeding risk calculator; predicts 1-year major bleeding risk for personalized DAPT decisions.

CHA₂DS₂-VASc Score

Stroke risk in AF; guides anticoagulation decisions in ACS patients with new-onset AF.

HAS-BLED Score

Bleeding risk in anticoagulated patients; useful for ACS with AF on anticoagulation + DAPT.

SYNTAX Score

Assesses coronary complexity; guides PCI vs. CABG decision in multivessel ACS (especially NSTE-ACS).

Residual SYNTAX Score

Evaluates completeness of revascularization; predicts outcomes in multivessel PCI cases.

EuroSCORE II

Surgical risk calculator; useful in ACS patients considered for urgent CABG (left main, complex anatomy).

SCAI Shock Classification

Stages cardiogenic shock severity (A–E); guides mechanical support strategy in ACS with shock.

Mehran Contrast Nephropathy

Predicts kidney injury risk from contrast exposure; useful before PCI in ACS with CKD.

Adult GFR Calculator

MDRD or CKD-EPI equations for renal function; critical for anticoagulation dosing in ACS.

Creatinine Clearance (CG)

Alternative GFR estimate; used for medication dosing in ACS patients with renal impairment.

Pooled Cohort ASCVD Risk

Primary prevention risk calculator; useful for assessing family members and lifestyle counseling post-ACS.

Lifetime ASCVD Risk

Long-term risk stratification for preventive counseling in post-ACS patients and families.

Corrected QT (QTc)

Assesses QT prolongation risk; relevant for patients on antiarrhythmics or with electrolyte abnormalities post-ACS.