What are the guidelines for coronary angiography after cardiac arrest?

Guidelines for Coronary Angiography After Cardiac Arrest

Perform emergent coronary angiography immediately for all cardiac arrest patients with suspected cardiac cause and ST-segment elevation on ECG—this is a Class I recommendation that improves both survival and neurologically favorable outcomes. 1

Immediate Coronary Angiography (Class I Recommendation)

For patients with ST-segment elevation:

• Coronary angiography should be performed emergently (same day as arrest, ideally within hours) for out-of-hospital cardiac arrest patients with suspected cardiac etiology and ST elevation on ECG 1
• This applies to both awake and comatose patients with STEMI 1
• Multiple observational studies demonstrate improved survival to hospital discharge and neurologically favorable outcomes in this population 1
• In series of consecutive post-arrest patients with suspected cardiovascular cause, 96% of patients with ST elevation had a coronary artery lesion amenable to emergency treatment 1

Critical timing consideration: Early ECG acquisition (≤7 minutes after ROSC) is associated with higher false-positive rates for STEMI (18.5% vs 5.8% when acquired >33 minutes after ROSC), so consider delaying ECG by at least 8 minutes after ROSC or repeating if the first ECG shows STEMI and was acquired very early 2

Selective Emergency Angiography (Class IIa/IIb Recommendation)

For patients WITHOUT ST-segment elevation but with high-risk features:

• Emergency coronary angiography is reasonable for selected adult patients without ST elevation who have: 1
  • Hemodynamic instability/shock
  • Electrical instability (recurrent arrhythmias)
  • Signs of significant ongoing myocardial damage
  • Evidence of ongoing ischemia
• In these unstable patients without ST elevation, 58% still have coronary lesions amenable to emergency treatment 1
• Multiple observational studies show improved survival and neurologically favorable outcomes with emergency angiography in this selected group 1

For comatose patients with STEMI:

• Awake patients with STEMI after cardiac arrest should undergo primary PCI—their outcomes are comparable to STEMI patients without cardiac arrest 1
• Comatose patients with STEMI and favorable prognostic features should undergo primary PCI 1
• Comatose patients with unfavorable prognostic features (unwitnessed arrest, no bystander CPR, non-shockable rhythm, CPR >30 minutes, time to ROSC >30 minutes, arterial pH <7.2, lactate >7 mmol/L) may have PCI considered after individualized assessment, though prognosis is poor 1

When NOT to Perform Emergency Angiography (Class III Recommendation)

Emergent coronary angiography is NOT recommended over a delayed or selective strategy in patients with ROSC after cardiac arrest who have ALL of the following: 1

• Absence of ST-segment elevation
• No shock/hemodynamic stability
• No electrical instability
• No signs of significant myocardial damage
• No ongoing ischemia

Key evidence: Multiple randomized controlled trials demonstrated no benefit of emergency coronary angiography over delayed angiography for stable patients without ST elevation 1

Special consideration for non-shockable rhythms without ST elevation: These patients have extremely low prevalence of acute coronary syndrome (only 1-2%), extremely poor survival, and routine emergency coronary angiography does not appear beneficial 3

Neurologic Status Should Not Delay Indicated Angiography

• Coronary angiography is reasonable in post-cardiac arrest patients for whom coronary angiography is otherwise indicated, regardless of whether the patient is comatose or awake (Class IIa) 1
• Comatose patients with ROSC benefit from invasive angiography when indicated, just as awake patients do 1

Practical Algorithm

1. Obtain 12-lead ECG as soon as possible after ROSC (ideally 8+ minutes after ROSC to reduce false positives) 1, 2

2. If ST elevation present + suspected cardiac cause:

   • Proceed immediately to coronary angiography regardless of neurologic status 1
   • Transfer to PCI-capable center if not already there 1

3. If NO ST elevation, assess for high-risk features:

   • Shock/hemodynamic instability
   • Electrical instability
   • Signs of significant myocardial damage
   • Ongoing ischemia

   If ANY high-risk feature present: Consider emergency angiography 1

   If ALL absent AND stable: Delay angiography for further risk stratification 1

4. Special populations to avoid emergency angiography:

   • Non-shockable rhythm + no ST elevation + stable = extremely low yield 3

Common Pitfalls

• Don't obtain ECG too early: ECGs acquired ≤7 minutes after ROSC have 18.5% false-positive rate for STEMI compared to 5.8% when acquired >33 minutes after ROSC 2
• Don't withhold angiography based solely on comatose status: Neurologic status alone should not determine whether to perform indicated coronary angiography 1
• Don't perform routine emergency angiography in stable patients without ST elevation: Multiple RCTs show no benefit over delayed strategy 1
• Don't assume non-shockable rhythms always need emergency catheterization: Without ST elevation and when stable, these patients have very low rates of treatable coronary disease 3