PAMI - Primary Angioplasty in Myocardial Infarction

What is Primary PCI?

Why is PAMI Preferred Over Fibrinolysis?

• Washington Manual of Medical Therapeutics, p. 155-156

Time Goals for Primary PCI

• Door-to-balloon time: ≤90 minutes from first medical contact (at a PCI-capable hospital)
• First medical contact to PCI: ≤120 minutes (including transfer time)
• If PCI cannot be performed within 120 minutes, fibrinolysis should be given instead

When is Primary PCI Indicated?

1. All STEMI patients presenting within 12 hours of symptom onset - primary PCI is the preferred strategy
2. 12-24 hours from symptom onset - still recommended if patient has ongoing symptoms
3. Cardiogenic shock / Killip class III-IV - PCI is always preferred even if transfer delays occur beyond standard time goals
4. Contraindication to fibrinolysis (e.g., recent surgery, active bleeding, prior intracranial hemorrhage)
5. Previous PCI or CABG

When is Primary PCI ALWAYS Preferred (Over Fibrinolysis)?

• Severe heart failure or cardiogenic shock (Killip III/IV or TIMI risk score ≥5)
• Contraindication to fibrinolytics
• Prior PCI or CABG
• Symptom onset >12 hours ago

Special Considerations

• If infarct artery is successfully treated, complete revascularization of non-culprit arteries reduces future cardiovascular death and MI
• Exception: In cardiogenic shock, the CULPRIT-SHOCK trial showed culprit-only PCI reduces all-cause mortality and need for renal replacement therapy vs. multivessel PCI

PAMI vs. Fibrinolysis - Choice Framework

• ROSEN's Emergency Medicine, p. 1031
• Washington Manual of Medical Therapeutics, p. 156-157

Key Landmark Trials Behind PAMI

• GUSTO IIb Angioplasty Substudy - showed PCI superior to tPA for acute MI
• PAMI trial (Grines et al.) - the original landmark trial showing primary balloon angioplasty was superior to fibrinolysis
• DANAMI-2, PRAGUE trials - showed benefit even when transfer was required for PCI

Clinical Summary

REPERFUSION DECISION - Most Critical

Which reperfusion strategy?

1. Symptom duration is <12 hours - PCI is first choice
2. Prior PTCA history - guidelines explicitly state PCI is always preferred over fibrinolysis in patients with prior PCI (the old stent/angioplasty site may be the site of re-stenosis/re-occlusion)
3. PCI gives superior TIMI-3 flow, less reinfarction, no intracranial bleed risk

If PCI is available within 120 minutes of first medical contact → go for primary PCI immediately

If PCI is NOT available within 120 minutes and no contraindications → give fibrinolysis now, then transfer for angiography within 24 hours

Immediate Management - Do This NOW

Step 1: Stabilization

• O2 if SpO2 <90%
• IV access, monitor (telemetry), pulse oximetry
• 12-lead ECG (confirm AWMI - check V1-V4 ST elevations)
• Serial ECGs if ongoing pain
• Target: ECG done within 10 minutes of arrival

Step 2: Upstream Medications (give immediately, regardless of reperfusion choice)

• If going for primary PCI → Ticagrelor 180 mg loading dose (preferred) OR Prasugrel 60 mg (avoid if >75 yrs, <60 kg, or CVA/TIA history) OR Clopidogrel 600 mg
• If getting fibrinolysis → Clopidogrel 300 mg only (not ticagrelor/prasugrel with thrombolytics)

• For primary PCI → UFH (preferred in cath lab, dose adjusted by ACT)
• For fibrinolysis → UFH (aPTT 2x ULN for ≥48 hrs) OR Enoxaparin (if creatinine normal)

Step 3: Reperfusion

Key Point About Prior PTCA History

• The old angioplasty site may have re-stenosed or a new lesion may have developed
• This makes fibrinolysis less predictable and PCI even more favorable
• Guidelines explicitly list prior PCI as a reason to prefer PCI over fibrinolysis
• At angiography, the interventionist can directly visualize the prior stent/vessel and act accordingly

Do NOT Do

• Do NOT give facilitated PCI (fibrinolytic + immediate PCI combined - Class III, harmful)
• Do NOT delay antiplatelet/anticoagulant while awaiting reperfusion decision
• Do NOT use prasugrel if patient is >75 yrs, <60 kg, or has h/o stroke/TIA
• Do NOT perform PCI on non-culprit vessels during the index procedure if patient develops cardiogenic shock - culprit-only PCI is preferred (CULPRIT-SHOCK trial)

Quick Decision Tree for Your Case

AWMI + 5.5 hrs symptoms + prior PTCA
         ↓
PCI available within 120 min?
    YES → Activate cath lab → Primary PCI (door-to-balloon ≤90 min)
    NO  → Fibrinolysis NOW (within 30 min of contact) → Transfer for angio in 24 hrs
         ↓
Both paths: ASA + P2Y12 + anticoagulant IMMEDIATELY

• Washington Manual of Medical Therapeutics, pp. 155-158

Your Patient's Full Timeline - Reconstructed

4:00 PM  → Chest pain starts (symptom onset)
5-6 PM   → Seen at another hospital/doctor
           → ECG done → AWMI confirmed
           → Loading dose given: Aspirin + Clopidogrel
           → Patient transferred to you
9:30 PM  → Now with you (transfer complete)
           → Total ischemia time = ~5.5 hours

Understanding "120 Minutes FMC to PCI"

The FMC-to-balloon clock for your patient:

FMC = 5:00-6:00 PM (when first hospital saw them)
Now = 9:30 PM
Time elapsed from FMC = 3.5 to 4.5 HOURS

What This Means Clinically

Option A: Primary PCI (still indicated, still beneficial)

• Symptom onset is <12 hours ago (5.5 hrs) - PCI still opens the artery and salvages myocardium
• Patient has prior PTCA - PCI is always preferred over fibrinolysis
• Patient already received Aspirin + Clopidogrel - they are antiplatelet-loaded and ready for the cath lab
• The 120-minute rule is a quality benchmark, not a contraindication to PCI

Activate the cath lab NOW. Every minute still counts - "time is muscle."

Option B: Fibrinolysis - Should you give it?

1. Patient already has Aspirin + Clopidogrel on board - adding a thrombolytic significantly increases bleeding risk
2. It has been >3-4 hours since loading - the early window for maximum fibrinolysis benefit is narrowing
3. Prior PTCA history makes PCI the preferred route
4. Fibrinolysis + dual antiplatelet = dangerous combination

What To Do Right Now at 9:30 PM

Immediate actions:

1. Repeat 12-lead ECG - confirm STEMI still present (or check if ST changes evolved)
2. Vitals - BP, HR, SpO2, check for signs of cardiogenic shock
3. Blood tests - Troponin (serial), CBC, creatinine, coagulation, glucose
4. Do NOT repeat antiplatelet loading - Aspirin + Clopidogrel already given
5. Add anticoagulant - UFH bolus (if not already given at referring hospital - check transfer notes)
6. Call cath lab - arrange primary PCI urgently

Medications to give NOW (if not already given):

Do NOT give:

• No second antiplatelet loading (already loaded)
• No fibrinolytics (dangerous now)
• No GPIIb/IIIa inhibitors routinely upfront

Summary in One Line

Patient had AWMI, was loaded with Aspirin + Clopidogrel at first hospital, now transferred to you at 5.5 hours - skip fibrinolysis, go straight for primary PCI, add UFH, and get him to the cath lab immediately.

What is Fibrinolysis (Thrombolysis)?

In STEMI, a blood clot blocks the coronary artery. Primary PCI = a doctor physically opens the artery with a wire/balloon. Fibrinolysis = giving a drug through IV that chemically dissolves the clot.

How Does It Work?

Clot is made of FIBRIN (a protein mesh)
      ↓
Fibrinolytic drug activates PLASMINOGEN
      ↓
Plasminogen → PLASMIN
      ↓
Plasmin BREAKS DOWN FIBRIN
      ↓
Clot dissolves → Artery opens

Available Drugs (Fibrinolytic Agents)

When to Give Fibrinolysis? (Indications)

• STEMI confirmed on ECG (ST elevation, new LBBB, or posterior MI)
• Symptom onset <12 hours ago
• Most effective in the first 3 hours - benefit reduces after that

Give within 30 minutes of patient reaching your hospital ("door-to-needle ≤30 min")

When NOT to Give (Contraindications)

Absolute (NEVER give):

• History of intracranial hemorrhage (brain bleed) - ever
• Ischemic stroke within 3 months
• Known brain AVM / aneurysm / tumor
• Head injury within 3 months
• Aortic dissection suspected
• Active bleeding anywhere
• BP >180/110 mmHg (uncontrolled)
• Acute pericarditis

Relative (use caution):

• Prior ischemic stroke >3 months ago
• Previous streptokinase use (give a different drug)
• Recent major surgery within 3 weeks
• Active peptic ulcer
• Prolonged CPR >10 minutes

Advantages vs Disadvantages

What Happens After Fibrinolysis?

• Chest pain relieved
• ST elevation reduces by ≥50% on ECG
• Reperfusion arrhythmias appear (accelerated idioventricular rhythm - actually a good sign!)

Fibrinolysis vs Primary PCI - Simple Comparison

• Washington Manual of Medical Therapeutics, pp. 157-158

For YOUR Patient Specifically

1. Already has Aspirin + Clopidogrel on board → bleeding risk too high
2. Has prior PTCA history → PCI always preferred
3. Still within 12-hour window → go directly for primary PCI