Can you outline the step‑by‑step procedure for coronary angiography and percutaneous coronary intervention (angioplasty)?

Coronary Angiography and Percutaneous Coronary Intervention: Step-by-Step Procedural Overview

Pre-Procedural Preparation and Antiplatelet Loading

All patients undergoing PCI must receive aspirin and a P2Y12 inhibitor loading dose before the procedure, with the specific agent and timing determined by clinical presentation. 1

Antiplatelet Regimen by Clinical Scenario:

Elective PCI (Stable CAD):

• Aspirin 81-325 mg for patients already on therapy, or 325 mg non-enteric for aspirin-naïve patients 1
• Clopidogrel 600 mg loading dose once coronary anatomy is known and PCI decision is made 1
• Loading should occur at least 6 hours before procedure when possible 2

Acute Coronary Syndrome (ACS):

• Aspirin 150-300 mg oral loading (or 75-250 mg IV) 1
• P2Y12 inhibitor options: Ticagrelor 180 mg loading (preferred), Prasugrel 60 mg loading (if P2Y12-naïve), or Clopidogrel 600 mg if others contraindicated 1
• Pre-treatment with GP IIb/IIIa inhibitors before knowing coronary anatomy is NOT recommended 1

Post-Fibrinolytic Therapy:

• Clopidogrel 300 mg if within 24 hours of fibrinolysis, or 600 mg if >24 hours after fibrinolysis 1

Vascular Access and Anticoagulation

Radial artery access is the standard approach and should be used unless specific procedural considerations mandate femoral access. 1

Procedural Anticoagulation:

• Unfractionated heparin (UFH) 70-100 U/kg is the standard anticoagulant 1
• Bivalirudin is an acceptable alternative to UFH plus GP IIb/IIIa inhibitors in low-risk patients 1
• In patients with heparin-induced thrombocytopenia, use bivalirudin or argatroban instead of heparin 1

Diagnostic Coronary Angiography Phase

The diagnostic angiogram should evaluate all coronary territories using multiple projections to assess lesion severity, complexity, and suitability for intervention. 3

Key Angiographic Assessment:

• Obtain views of left main, left anterior descending, circumflex, and right coronary arteries 3
• Assess lesion characteristics: location (ostial, bifurcation, chronic total occlusion), calcification severity, thrombus burden, and vessel tortuosity 1
• Perform left ventriculography when indicated to assess ventricular function 3
• Calculate SYNTAX score for multivessel disease to guide revascularization strategy (though interobserver variability limits its utility) 1

Ad-Hoc vs. Staged Approach:

Ad-hoc PCI (immediate intervention following diagnostic angiography) is safe, feasible, and more cost-effective than staged procedures, with equivalent success and complication rates. 4, 5

• Success rates for ad-hoc PCI: 92.2% with major complication rates of 1.5% (0.8% death, 1.0% Q-wave MI, 0.5% emergency CABG) 4
• All patients should be prepared before angiography for potential immediate angioplasty 4

Percutaneous Coronary Intervention Execution

Lesion Preparation and Adjunctive Imaging:

Intracoronary imaging with intravascular ultrasound (IVUS) or optical coherence tomography (OCT) should be performed to optimize stent sizing and placement. 1

• Minimum 25 intracoronary imaging procedures required for competency 1
• Quantitative coronary angiography (QCA) with routine postdilation provides outcomes comparable to intravascular imaging when imaging is unavailable 6

Coronary physiology assessment with fractional flow reserve (FFR) or non-hyperemic pressure ratios should be performed for intermediate lesions. 1

• Minimum 25 coronary physiology procedures required for competency 1

Stent Selection and Deployment:

Drug-eluting stents (DES) are recommended over bare-metal stents (BMS) for all PCI regardless of clinical presentation, lesion type, planned non-cardiac surgery, anticipated DAPT duration, or concomitant anticoagulation. 1

For bifurcation lesions, stent the main vessel only with provisional balloon angioplasty ± stenting of the side branch. 1

Specialized Techniques (Use Selectively):

Cutting balloon angioplasty:

• May be considered for in-stent restenosis or ostial side branch lesions to avoid slippage-induced trauma 1
• Should NOT be performed routinely 1

Laser angioplasty:

• Should NOT be used routinely during PCI 1

Rotational atherectomy:

• Reserved for heavily calcified lesions not amenable to balloon angioplasty 1

Glycoprotein IIb/IIIa Inhibitor Administration

STEMI Patients:

In primary PCI with UFH, administration of GP IIb/IIIa inhibitor (abciximab, double-bolus eptifibatide, or high-bolus tirofiban) is reasonable regardless of clopidogrel pretreatment. 1

• Routine pre-catheterization lab administration as upstream strategy is NOT beneficial 1
• Intracoronary abciximab administration may be reasonable 1

UA/NSTEMI Patients:

In high-risk patients (elevated troponin) not treated with bivalirudin and not adequately pretreated with clopidogrel, administer GP IIb/IIIa inhibitor at time of PCI. 1

Elective PCI:

GP IIb/IIIa inhibitor administration is reasonable in elective PCI with stent placement. 1, 2

Post-Procedural Management

Immediate Post-PCI Antiplatelet Therapy:

Aspirin must be continued indefinitely at 81 mg daily (preferred over higher doses). 1, 2

P2Y12 inhibitor duration depends on stent type and clinical indication: 1

ACS patients (BMS or DES):

• Minimum 12 months of P2Y12 inhibitor therapy 1
• Options: Clopidogrel 75 mg daily, Prasugrel 10 mg daily, or Ticagrelor 90 mg twice daily 1

Non-ACS patients with DES:

• Clopidogrel 75 mg daily for at least 12 months if not at high bleeding risk 1

Non-ACS patients with BMS:

• Clopidogrel minimum 1 month, ideally up to 12 months (minimum 2 weeks if high bleeding risk) 1

Brachytherapy patients:

• Clopidogrel 75 mg indefinitely plus aspirin indefinitely 1, 2

High-Risk Lesion Monitoring:

For unprotected left main PCI, perform follow-up coronary angiography between 2-6 months post-procedure. 1, 2

In catastrophic-risk lesions (unprotected left main, bifurcating left main, last patent vessel), consider platelet aggregation studies and increase clopidogrel to 150 mg daily if <50% platelet inhibition is achieved. 1, 2

Vasospasm Prevention:

Administer nitrates (isosorbide dinitrate) to prevent coronary vasospasm in the immediate post-procedural period and treat no-reflow phenomenon if it occurs. 2

Critical Pitfalls to Avoid

Never discontinue dual antiplatelet therapy prematurely—this dramatically increases catastrophic stent thrombosis risk, particularly with DES. 2

• Stent thrombosis occurs in 1.1-2.4% of patients depending on antiplatelet regimen 2
• Subacute or late thrombosis is especially problematic after brachytherapy 1

Counsel patients extensively on DAPT necessity and risks before stent placement, especially DES, and pursue alternative therapies (BMS or balloon angioplasty) if patients cannot comply with recommended DAPT duration. 1

Avoid GP IIb/IIIa inhibitors in patients with prior stroke or active bleeding—prasugrel carries FDA boxed warning for significant or fatal bleeding risk. 2

In renal impairment (CrCl <30 mL/min), reduce tirofiban dose by 50% for both bolus and infusion. 2

• Use low- or iso-osmolar contrast media and minimize contrast volume in moderate-to-severe CKD 1

Do not administer prasugrel before coronary anatomy is known—this is NOT recommended. 1