Please provide a detailed percutaneous coronary intervention (PCI) protocol.

Percutaneous Coronary Intervention (PCI) Protocol

Pre-Procedural Planning and Patient Selection

All PCI procedures require thorough pre-procedural planning with detailed angiographic review; ad hoc PCI should be avoided in most cases to allow adequate time for risk-benefit assessment, patient counseling, and procedural strategy development. 1

Indications for PCI

Primary Indication:

• Symptom improvement (angina, exertional dyspnea, fatigue) despite optimal medical therapy is the only benefit of PCI demonstrated in randomized controlled trials and should be the primary indication. 1
• For chronic total occlusions (CTOs), PCI should be considered when angina is resistant to medical therapy or when large areas of documented ischemia exist in the territory of the occluded vessel (Class IIA/Level B). 1

STEMI Indications:

• Primary PCI within 12 hours of symptom onset (Class I/Level A). 1
• Door-to-balloon time ≤90 minutes for hospitals with PCI capability (Class I/Level B). 1
• Door-to-balloon time ≤120 minutes for hospitals without PCI capability requiring transfer (Class I/Level B). 1
• Severe heart failure or cardiogenic shock regardless of time delay (Class I/Level B). 1
• Contraindications to fibrinolytic therapy with symptoms <12 hours (Class I/Level B). 1
• Clinical/electrocardiographic evidence of ongoing ischemia 12-24 hours after symptom onset (Class IIA/Level B). 1

Post-Fibrinolysis Strategy:

• Coronary angiography 3-24 hours after successful fibrinolysis in hemodynamically stable patients (Class IIA/Level A). 1
• Immediate angiography for moderate-to-large myocardium at risk with evidence of failed fibrinolysis (Class IIA/Level B). 1

Pre-Procedural Assessment and Preparation

Angiographic Review

Perform dual coronary angiography using two catheters and pressure-monitoring systems in every case—this is the simplest yet most powerful technique for improving technical success and reducing complications. 1

Focus angiographic review on four characteristics:

• Proximal cap morphology 1
• Occlusion length, course, and composition (calcium burden) 1
• Quality of distal vessel 1
• Characteristics of collateral circulation 1

Patient Counseling

• Conduct office-based risk/benefit conversation before CTO-PCI to provide realistic expectations (strongly encouraged). 1
• Counsel patients on the need for and risks of dual antiplatelet therapy (DAPT) before stent placement, especially drug-eluting stents (DES); pursue alternative therapies if patients are unwilling or unable to comply with recommended DAPT duration. 1

Procedural Protocol

Anticoagulation Management

Unfractionated Heparin:

• With GP IIb/IIIa inhibitor: 50-70 U/kg bolus, target ACT 200-250 seconds 1
• Without GP IIb/IIIa inhibitor: 70-100 U/kg bolus, target ACT 250-300 seconds 1
• Recommended target ACT for eptifibatide and tirofiban is <300 seconds 1
• Postprocedural heparin infusions are not recommended during GP IIb/IIIa therapy 1

Enoxaparin:

• If PCI within 8 hours of last subcutaneous dose: no additional anticoagulant needed 1
• If PCI 8-12 hours after last subcutaneous dose: administer 0.3 mg/kg IV immediately before PCI 1
• ACT should not be used to guide anticoagulation in patients on low-molecular-weight heparin 1
• Sheath removal: 4 hours after last IV dose or 6-8 hours after last subcutaneous dose 1

CTO-Specific Techniques

Guidewire Selection Strategy:

• For tapered proximal cap or visible microchannel: begin with polymer-jacketed, low-penetration-force, tapered guidewire to minimize perforation risk. 2
• For blunt proximal cap: start with intermediate-penetration-force polymer-jacketed or composite-core guidewire; reserve stiff, high-penetration-force wires for highly resistant caps. 2
• Escalate sequentially from low to intermediate to high penetration force only when necessary. 2

Wire Escalation/De-escalation:

• After penetrating proximal cap by 1-2 mm, immediately de-escalate to less-penetrating guidewire to traverse CTO body safely, reducing distal vessel perforation risk. 2
• Maintaining aggressive, high-penetration-force wires beyond proximal cap markedly increases perforation risk 2

Microcatheter Use:

• Always use a microcatheter (not over-the-wire balloon) to support and manipulate guidewires during antegrade CTO crossing. 1, 2
• Microcatheters provide distal tip marker for precise positioning, low profile, superior wire-to-lumen ratio, and kink-resistant metallic braid 2

Four CTO Crossing Strategies:

• Antegrade wire escalation 1
• Antegrade dissection/reentry 1
• Retrograde wire escalation 1
• Retrograde dissection/reentry 1

Strategic Flexibility:

• Change equipment and technique when progress stalls; avoid persisting with same guidewire or strategy—timely adjustments improve success rates and reduce radiation/contrast exposure. 1, 2

Guide Catheter Selection

Standard Anatomy:

• Begin with Judkins Right 4.0 catheter for routine RCA engagement 3

Difficult RCA Ostium/Dilated Aortic Root:

• Use Amplatz Left (0.75 or 1), MAC (3.0 or 4.0), XB-RCA, or Ikari Left (3.5 or 4.0) catheters for superior backup support 3
• Immediately switch to alternative shapes when standard JR fails 3

Advanced Techniques:

• Deep inspiration technique to straighten angle between innominate artery and ascending aorta 3
• Counterclockwise rotation during deep inspiration to position catheter at aortic knob in LAO view 3
• Use exchange-length wires for all catheter exchanges once safely seated in ascending aorta 3

Embolic Protection and Hemodynamic Support

Saphenous Vein Graft PCI:

• Embolic protection devices should be used during SVG PCI when technically feasible (Class I/Level B). 1

High-Risk PCI:

• Elective insertion of appropriate hemodynamic support device may be reasonable in carefully selected high-risk patients (Class IIb/Level C) 1

Stent Optimization

Every effort should be made to optimize stent deployment in CTO-PCI, including frequent use of intravascular imaging. 1

Post-Procedural Management

Dual Antiplatelet Therapy (DAPT)

Loading Doses (before or during PCI):

• Clopidogrel 600 mg for ACS patients (Level B) 1
• Prasugrel 60 mg for ACS patients (Level B) 1
• Ticagrelor 180 mg for ACS patients (Level B) 1
• Clopidogrel 300 mg within 24 hours after fibrinolytic therapy; 600 mg if >24 hours after fibrinolytic therapy (Level C) 1

Maintenance Therapy:

• Aspirin 81 mg daily (preferred over higher doses, Level B) 1

P2Y12 Inhibitor Duration:

• ACS patients receiving any stent (BMS or DES): at least 12 months with clopidogrel 75 mg daily, prasugrel 10 mg daily, or ticagrelor 90 mg twice daily (Level B). 1
• Non-ACS patients receiving DES: clopidogrel 75 mg daily for at least 12 months if not at high bleeding risk (Level B). 1
• Non-ACS patients receiving BMS: clopidogrel for minimum 1 month, ideally up to 12 months (minimum 2 weeks if increased bleeding risk, Level B). 1
• If bleeding risk outweighs benefit, earlier discontinuation (<12 months) is reasonable (Class IIA/Level C) 1

Vascular Access Management

Sheath Removal:

• Post-PCI hematocrit should be monitored for decrease >5-6% 1
• Monitor for vascular complications including retroperitoneal hematoma (signs: hypotension, suprainguinal tenderness, severe back or lower-quadrant abdominal pain) 1
• Computed tomography confirms retroperitoneal hematoma diagnosis; >80% can be treated conservatively with transfusions 1

Hospital Discharge

Most patients can be safely discharged within the next calendar day after uncomplicated elective PCI. 1

Discharge protocols should address:

• Monitoring for recurrent myocardial ischemia 1
• Achieving hemostasis at catheter insertion site 1
• Detecting and preventing contrast-induced renal failure 1
• Monitoring vascular closure device results if used 1
• Implementing secondary atherosclerosis prevention programs 1

Critical Pitfalls to Avoid

Organizational Gaps:

• Ensure continuous clopidogrel administration without gaps after stent implantation—even brief interruptions can cause catastrophic stent thrombosis. 4

Procedural Errors:

• Do not persist with Judkins Right when inadequate support is evident; early catheter exchange prevents prolonged procedure time and complications 3
• Avoid forceful attempts to engage difficult ostium; use gentle technique with appropriate catheter shape selection 3
• Do not perform PCI in noninfarct artery at time of primary PCI in hemodynamically stable patients (Class III: Harm/Level B) 1

Strategic Errors:

• Avoid ad hoc CTO-PCI in most cases; preplanning minimizes contrast/radiation dose, reduces fatigue, and allows detailed patient discussion 1
• Do not perform PCI in totally occluded infarct artery >24 hours after STEMI in hemodynamically stable asymptomatic patients without severe ischemia (Class III: No Benefit) 1