What is the biggest difference in previous guidelines and the 2025 American Heart Association (AHA)/American College of Cardiology (ACC) guidelines concerning emergent cardiac catheterization in out-of-hospital cardiac arrest (OHCA) patients?

Major Shift in 2025 AHA/ACC Guidelines: Restriction of Emergent Catheterization for Non-STEMI OHCA Patients

The 2025 AHA/ACC guidelines represent a fundamental departure from previous recommendations by explicitly stating that immediate angiography is NOT recommended (Class 3: No Benefit) for comatose OHCA patients who are electrically and hemodynamically stable without STEMI, whereas 2015 guidelines considered this reasonable (Class IIa). 1

The Critical Change in Non-STEMI Management

Previous 2015 Guideline Approach

• Emergency coronary angiography was considered reasonable (Class IIa) for select comatose adult patients after OHCA of suspected cardiac origin but without ST elevation on ECG, particularly if they were electrically or hemodynamically unstable 1
• The 2015 European guidelines went further, suggesting catheterization should be "considered as soon as possible (less than 2 hours)" in non-STEMI patients without obvious non-coronary cause, especially if hemodynamically unstable 1
• This created a permissive environment where many centers performed immediate catheterization on most OHCA survivors regardless of ECG findings 2

New 2025 Guideline Restrictions

The 2025 guidelines now provide a clear algorithmic approach based on clinical stability and ECG findings:

For STEMI patients (unchanged strong recommendation):

• Noncomatose OR comatose with favorable prognostic features + STEMI → Proceed to PPCI (Class I, LOE B-NR) 1
• Comatose with unfavorable prognostic features + STEMI → PPCI may be reasonable after individualized assessment (Class 2b, LOE C-LD) 1

For Non-STEMI patients (NEW restrictive recommendation):

• Comatose + electrically/hemodynamically stable + no STEMI → Immediate angiography NOT recommended (Class 3: No Benefit, LOE A) 1
• This represents the highest level of evidence (LOE A) against routine immediate catheterization in this population 1

Evidence Driving This Change

The 2025 restriction is based on multiple randomized controlled trials (reflected in the LOE A designation) that demonstrated:

• No survival benefit from immediate versus delayed catheterization in stable non-STEMI OHCA patients 1
• The COACT trial specifically compared immediate versus delayed strategies in non-STEMI OHCA, finding no difference in outcomes 2
• Observational data showing extremely high mortality (98%) in patients undergoing catheterization without prior ROSC, questioning the utility of this aggressive approach 3

Practical Clinical Algorithm for 2025

Step 1: Obtain 12-lead ECG immediately post-ROSC

Step 2: Assess for STEMI

• STEMI present → Activate cath lab, transfer to PPCI center (Class I) 1, 4
  • If awake/noncomatose → Proceed immediately to PPCI 1
  • If comatose with favorable features (witnessed arrest, bystander CPR, shockable rhythm, CPR <30 min, pH >7.2, lactate <7 mmol/L, age <85) → Proceed to PPCI 1, 4
  • If comatose with unfavorable features → Consider PPCI after rapid assessment 1

Step 3: If NO STEMI, assess hemodynamic/electrical stability

• Unstable (ongoing shock requiring escalating vasopressors, recurrent VT/VF) → Emergency catheterization may be considered 1
• Stable (hemodynamically and electrically) → Defer catheterization for risk stratification 1

Critical Pitfalls to Avoid

Do NOT delay STEMI patients for:

• Hemodynamic optimization—manage hypotension with vasopressors en route to cath lab 5
• Initiation of targeted temperature management—this can be safely combined with PCI 4, 6
• Neurologic prognostication—comatose state alone should not preclude catheterization if STEMI is present 4

Do NOT perform immediate catheterization on:

• Stable, comatose non-STEMI patients—this is now explicitly not recommended (Class 3) 1
• Patients without ROSC prior to catheterization—mortality approaches 98% in this population 3

Unchanged Strong Recommendations

The following remain Class I recommendations in 2025:

• Preferential EMS transfer of cardiac arrest patients with STEMI to PPCI-capable centers (Class I, LOE C-LD) 1
• Emergency coronary angiography for OHCA patients with suspected cardiac etiology and ST elevation (Class I, LOE B-NR) 1
• Integration of catheterization with targeted temperature management protocols 4, 6

Unfavorable Prognostic Features for Risk Stratification

When assessing comatose STEMI patients, consider these validated poor prognostic indicators:

• Unwitnessed arrest 1
• No bystander CPR 1
• Nonshockable rhythm 1
• CPR duration >30 minutes 1
• Time to ROSC >30 minutes 1
• Arterial pH <7.2 1
• Lactate >7 mmol/L 1
• Age >85 years 1
• End-stage renal disease on dialysis 1