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Cardiology
Percutaneous Coronary Intervention General Principles
Built from Cardiovascular Catheterization and Intervention: A Textbook of Coronary, Peripheral, and Structural Heart Disease
What’s inside
15 sections · 150 slides
Overview
- Scope of this presentation
PCI and its evolution
- Minimally invasive treatment for coronary artery disease Relieves coronary stenosis and occlusion Restores blood flow to ischaemic myocardium Over two million procedures worldwide in 2023 Evolved over 50 years of device and technique gains
- $215 bn
- Andreas Gruntzig performed the first case in 1977 Awake human patient, balloon dilatation of a stenosis That first patient survives nearly 50 years later Limited by elastic recoil and neointimal proliferation Consequences: acute thrombosis and restenosis
- Balloon dilatation of a coronary stenosis
- Introduced in 1987 by Sigwart and colleagues Scaffold left in the vessel after dilatation Major gain: abolished early elastic recoil New problems: stent thrombosis, in-stent restenosis Restenosis driven by neointimal hyperplasia
- First implanted 1999; drug inhibits neointimal growth First generation: less restenosis, more late thrombosis First generation therefore needed prolonged DAPT Second generation: less TLR and less stent thrombosis Third generation: addresses durable-polymer hypersensitivity
- Expanded stent within the coronary artery
- Designed to dissolve after supporting the artery Rationale: avoid late thrombosis of permanent metal First generation: more thrombosis than 2nd-gen DES None currently commercially available Novel scaffolds and drug-coated balloons in development
- Problem solved at each device generation
Indications and appropriate use
- ACC/AHA/SCAI and ESC guidelines govern practice Both stress patient-centric decision-making Decisions rest on clinical presentation Also on anatomical complexity of the disease And on the potential benefit to that patient
- NSTE-ACS: early invasive strategy for high-risk patients High risk: positive biomarkers, dynamic ST changes Also haemodynamic instability Class I in both ACC/AHA/SCAI and ESC guidelines Early PCI typically within 24 hours of presentation
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- TIMACS: early versus delayed invasive intervention in ACS VERDICT: early versus standard care invasive treatment Both showed benefit of early PCI in high-risk patients Endpoints: recurrent ischaemia, urgent revascularisation Overall mortality also reduced versus conservative care
- PCI is the preferred treatment; superior to medical therapy Class I, Level of Evidence A in both guideline sets Reperfusion goal: within 120 min of first medical contact Door-to-balloon target: less than 90 minutes Rescue PCI indicated when fibrinolysis fails
- 2024 ESC guidance weighs symptoms, ischaemia, anatomy Class I Level A: angina despite optimised GDMT PCI relieves symptoms and improves quality of life Mortality benefit possible in left main or multivessel CAD Class I Level C: 1- or 2-vessel disease, no left main
- Non-invasive testing quantifies ischaemic burden Stress imaging or coronary CT angiography used High ischaemic burden strengthens the case for PCI Asymptomatic with large ischaemia: Class IIa, Level B Large ischaemia signals higher future event risk
- Reading class and level of recommendation
- Recommendations for Pci in Different Patient Subgroups
- Recommendations for Pci in Sihd
PCI versus medical therapy
- Early invasive strategy reduces adverse outcomes Benefit shown against medical therapy alone Intermediate- and low-risk patients: Class IIa Optimised medical therapy then delayed invasive is reasonable Individualised decision-making in this middle group
- Evidence overwhelmingly favours PCI over medical therapy PAMI compared primary angioplasty with thrombolysis DANAMI-2 compared angioplasty with fibrinolytic therapy Both: significant reduction in mortality and reinfarction PCI is the gold standard in ACC/AHA/SCAI and ESC guidance
- 2024 ESC guidance prioritises GDMT in stable disease PCI remains a tool for symptom relief when GDMT fails Class I Level A: PCI to relieve angina not controlled by GDMT Reduces angina frequency, improves quality of life Effect greatest with substantial ischaemic burden
- Compared PCI plus GDMT with GDMT alone in SIHD No significant difference in survival No difference in prevention of myocardial infarction Established GDMT as first-line in stable disease
- Initial invasive versus conservative strategy in SIHD PCI enhanced symptom relief and quality of life No significant reduction in major adverse events Routine PCI not recommended if asymptomatic or mild
- Pci versus Medical Therapy in Sihd
- Pci versus Medical Management
PCI versus surgical revascularisation
- SYNTAX score grades anatomic complexity of CAD Low score 22 or less: PCI or CABG may be appropriate Intermediate score 23 to 32: CABG generally preferred High score 33 or more: CABG generally preferred CABG benefits: mortality, stroke, repeat revascularisation
- CABG preferred over PCI in diabetic multivessel CAD FREEDOM: lower mortality and MI with CABG Absolute survival advantage 6% at 8 years Benefit even with relatively less severe CAD Class I recommendation for CABG in both guideline sets
- Impaired LV function due to ischaemic cardiomyopathy STICH: no difference between CABG and GDMT at 5 years Marked, accelerating survival advantage by 10 years Propensity-matched data: CABG better than PCI at 9 years Also fewer MIs and less repeat revascularisation
- EXCEL
- High SYNTAX score left main: Class I for CABG Endorsed by ACC/AHA/SCAI and ESC guidelines Low-to-intermediate SYNTAX: PCI reasonable, Class IIa CABG preferred for complex left main disease Decisions individualised to the patient and context
- Choosing between PCI and CABG
- Preferred Revascularization Strategies for Multivessel and Left Main Cad
Steps in the procedure
- Sequence of a percutaneous coronary intervention
- First step of every PCI procedure Femoral artery was historically the primary site Smaller tools now permit radial access in most cases Radial: less bleeding, shorter stay, better comfort Sheath maintains access for catheter exchange
- MATRIX and RIVAL studied access site in ACS Radial reduced major adverse cardiovascular events Radial reduced bleeding versus femoral access Class I ACC/AHA/SCAI recommendation for radial access Femoral appropriate when large catheters are needed
- Indications for Radial and Femoral Access in Pci
- Performed after access to visualise coronary anatomy Identifies location, extent and severity of stenoses Contrast injected through the catheter Real-time X-ray shows the vessel lumen Angiogram guides selection of the strategy
- Coronary angiogram showing arterial narrowing
- Guidewire advanced across the identified target lesion Serves as the rail for balloons and stents Wire choice depends on lesion anatomy Soft-tipped wires for simpler lesions Supportive steerable wires for tortuous or calcified vessels Class I recommendation in both guideline sets
- FFR assesses haemodynamic significance of a stenosis IVUS and OCT image vessel wall and plaque morphology Used to judge whether a lesion needs treatment Also to optimise stent placement Confirm full expansion and apposition to the wall
- Modifies plaque or thrombus before stent implantation Makes the lesion amenable to stenting Rotational or orbital atherectomy debulks calcium Improves stent expansion, reduces malapposition Class IIa when balloon angioplasty fails to prepare
- Used for thrombus-laden lesions, mainly in ACS Routine thrombectomy is not recommended Selective use with high thrombus burden: Class IIa Laser atherectomy modifies fibrotic or thrombotic plaque
- Lesion Preparation Tools
- Cornerstone of PCI; maintains patency after dilatation DES have largely replaced bare-metal stents DES deliver antiproliferative drug locally Drug inhibits neointimal hyperplasia SORT OUT IV and COMPARE support Class I DES use
- Balloon-expanded stent within the artery
- Coronary stent in position
- Balloon-mounted stents and delivery catheters
- Performed after stent deployment Non-compliant balloon used to expand fully Ensures optimal expansion and apposition Minimising malapposition lowers thrombosis risk Particularly recommended in calcified lesions
- Final step: confirm success of the intervention Angiography checks complete revascularisation Look for dissection, perforation, residual stenosis IVUS or OCT confirm stent placement and expansion Standard practice after every stent implantation
- Sequence of stent placement across a coronary stenosis
Arterial access sites
- PCI can be performed by several arterial routes Radial, femoral, ulnar and brachial arteries Each has distinct advantages and challenges Trial evidence guides site selection
- Preferred approach for most PCI procedures Reduced major bleeding versus femoral access Fewer major vascular complications Lower mortality reported in trial evidence RIVAL, RIFLE-STEACS and MATRIX support this Class I ACC/AHA/SCAI recommendation
- Summary of Radial Access Studies
- Remains valid for complex interventions Also used in cardiogenic shock Allows larger-bore catheters when needed Class IIa recommendation Ultrasound guidance reduces complication rates FAUST: fewer complications, better puncture success
- Access Sites for Pci
- Ulnar: alternative when radial access not feasible Useful when the ulnar artery is the larger vessel Avoid using radial and ulnar together: hand ischaemia Brachial access is much less common Risks: median nerve proximity, small calibre Higher bleeding risk as compression is difficult
Lesion types and calcium
- Lesions classified by composition and morphology Composition drives procedural complexity and strategy Lesion characteristics predict procedural success They also predict the risk of complications AHA and SCAI categories: thrombotic, lipid, fibrotic, calcific
- Typically occur in acute coronary syndromes Highly unstable and prone to embolisation during PCI Embolisation causes distal occlusion and infarction Thrombectomy reduces thrombus burden after stenting Class IIa; use selectively with large thrombus burden
- High lipid concentration within the plaque Associated with positive vessel remodelling Plaque instability with higher risk of rupture Rupture amplifies risk of acute coronary syndrome IVUS or OCT characterise these plaques Avoid landing a stent edge in lipid-rich plaque
- Typically more stable than thrombotic or lipid lesions Still cause significant luminal narrowing Less susceptible to plaque rupture Reduced flow can produce stable ischaemic heart disease Managed with the standard PCI approach
- Among the most challenging lesions to treat Calcium impairs balloon expansion Hinders stent delivery, causes under-expansion Higher rates of restenosis and stent thrombosis Need rotational or orbital atherectomy, or lithotripsy
- Lesion Types and Recommended Management
- Accompanies atherosclerosis, more prevalent with age Risk factors: chronic kidney disease, diabetes, hypertension Also tobacco use, obesity, inflammation, familial disease Presents as microcalcification or fibrocalcification Or as calcified nodules Each pattern affects PCI outcomes differently
- Pre-procedure CT shows location and extent of calcium Fluoroscopy can characterise calcium during the case Fluoroscopy limited by its resolution IVUS and OCT detect and characterise calcium better OCT measures superficial calcium thickness IVUS measures only calcium arc and length
- Nodules can disrupt the fibrous cap and cause thrombus Found in about 32% of severely calcified lesions Associated with more adverse events and restenosis OCT distinguishes eruptive from non-eruptive nodules Long calcified lesions risk stent under-expansion Image severely calcified segments before stenting
- PCI for calcified CTO lesions is complex Lower success rates than non-calcified CTOs Higher complication risk Pre-procedural and intravascular imaging essential Imaging maps calcium distribution for strategy Identify less calcified areas for wiring and reentry
- Rotational: high-speed diamond-tipped burr ablates calcium Class IIa when calcified lesions resist balloon expansion Risks include embolisation and dissection Orbital: orbital motion ablates calcium Useful in severe or circumferential calcification Provides smoother vessel preparation
- Sonic pressure waves fracture calcium in the artery wall DISRUPT CAD trials showed efficacy and safety Facilitates stent delivery and expansion Particularly useful for thick, resistant calcification ACC/AHA/SCAI Class IIa recommendation
- Calcium modification: mechanism by device
- Intravascular imaging essential in calcified lesion PCI Imaging guides use of calcium modification tools IVUS advised for complex or left main stenting OCT a reasonable alternative to IVUS OCT measures calcium thickness accurately Adjunctive devices used for severe calcification
- Management of Calcific Lesions
Bifurcation lesions
- Bifurcation lesions involve two branches of an artery Introduced at the 2005 European Bifurcation Club Congress Scores significant stenosis, defined as over 50% Three segments: proximal main, distal main, side branch Each segment scored 1 for stenosis or 0 for none The pattern guides the treatment strategy
- Provisional: stent main branch, side branch if needed Two-stent techniques include double kissing crush DKCRUSH-V: DKCRUSH better than provisional stenting Less restenosis and target lesion revascularisation Class IIa for DKCRUSH in complex bifurcations
- Double kissing crush technique
- Nano-crush is a revised version of DKCRUSH Minimises metal at the carina Requires fewer kissing balloon inflations T-and-protrude and culotte are simpler alternatives Both require only one kissing balloon inflation Culotte suits similar main and side branch calibre
- Techniques for Treating Bifurcation Lesions
Intracoronary physiology and imaging
- FFR, iFR, IVUS and OCT now central to guiding PCI Allow precise assessment and treatment of CAD Most valuable where angiography is insufficient 2024 ESC guidelines: intracoronary imaging Class I Level A Improves procedural and clinical outcomes
- Measures pressure difference across a stenosis Assesses physiological significance of the lesion Pressure wire introduced into the coronary artery Hyperaemic agent, typically adenosine, is given Ratio of distal pressure to aortic pressure
- FFR 0.80 or less indicates an ischaemia-causing lesion That value warrants revascularisation Most useful in intermediate coronary lesions FAME trials validated FFR-guided PCI Reduces unnecessary stenting versus angiography alone Identifies truly ischaemic lesions in multivessel disease
- Measures pressure gradient without a hyperaemic agent Recorded during the wave-free period of the cycle Microvascular resistance naturally minimal then Avoids adenosine and its patient discomfort DEFINE-FLAIR and iFR-SWEDEHEART: non-inferior to FFR Endpoints: death, myocardial infarction, revascularisation
- Provides cross-sectional images of the coronary artery Assesses vessel size, plaque burden, stent deployment Catheter transducer emits high-frequency ultrasound Reflected waves build the cross-sectional image Guides optimal stent size and deployment technique
- Especially useful in complex PCI Significant calcification, long lesions, bifurcations Also left main coronary artery disease IVUS-XPL, ULTIMATE and RENOVATE-COMPLEX-PCI Reduced target vessel failure, better long-term outcomes Preferred over OCT in left main or heavy calcium
- Higher image resolution than IVUS Uses near-infrared light to build the image Evaluates fibrous caps and lipid-rich plaques Detects stent malapposition ILUMIEN III and ILUMIEN IV support its use Better stent expansion, fewer adverse events
- Limited tissue penetration compared with IVUS Less effective in large vessels Also less effective in heavily calcified lesions Requires blood clearance to image Difficult in large proximal vessels Increases the contrast dose given
- IVUS compared with OCT
- Intravascular ultrasound cross-sections
- Recommendations for Intracoronary Imaging
- Use shows economic, racial and gender disparities Lower-income patients less likely to receive imaging Cost and hospital resources drive part of the gap Women less likely to receive imaging than men Linked to system and provider biases Imaging now Class I: access must be equitable
Periprocedural pharmacology
- Cornerstone of management during the procedure Prevents acute stent thrombosis and embolisation Agent chosen by institutional protocol Also by patient characteristics and procedural details Bleeding risk weighed in every choice
- Standard anticoagulant for PCI for many years Efficacious, easy to use, reversible with protamine Initial bolus 70 to 100 units per kilogram Target activated clotting time 250 to 300 seconds ACT checked roughly every 30 minutes Class I recommendation in most PCI procedures
- Increased risk of bleeding Requires constant laboratory monitoring ACT must confirm therapeutic anticoagulation Monitoring burden during long procedures
- Direct thrombin inhibitor, alternative to heparin MATRIX and VALIDATE-SWEDEHEART: less major bleeding Efficacy not compromised in those trials ACUITY and ISAR-REACT 4 gave mixed results Concern centres on stent thrombosis risk BRIGHT: less bleeding than heparin plus a GPI
- Summary of Key Clinical Trials Assessing Bivalirudin in Pci
- Class IIa in patients with ACS undergoing PCI Particularly those at high bleeding risk Balance bleeding against stent thrombosis risk No ACT monitoring needed, but higher cost
- Enoxaparin: low-molecular-weight heparin Effective but used less often than UFH or bivalirudin Argatroban: direct thrombin inhibitor Used in heparin-induced thrombocytopenia Bolus 200 micrograms per kilogram Then infusion 15 micrograms per kilogram per minute
- Anticoagulants in Pci
- Potent antiplatelet agents used adjunctively in PCI Block fibrinogen binding to the platelet This is the final common pathway of aggregation Used in high-risk ACS with large thrombus burden Role reduced by potent oral P2Y12 inhibitors
- Considered with large thrombus burden or ongoing ischaemia Also in bailout situations during the procedure ACC/AHA/SCAI Class IIa recommendation EPIC, EPILOG and EPISTENT showed fewer ischaemic events Benefit greatest in ACS patients Increased bleeding demands careful patient selection
- Glycoprotein IIb/IIIa Inhibitors in Pci
Complications and their management
- Coronary artery dissection Coronary artery perforation Arrhythmias during or after the procedure Haemodynamic collapse Can cause infarction, stroke or death
- Tear in the vessel wall creating a false lumen Less common since stents came into use Feared during complex procedures such as CTO PCI Can obstruct flow, occlude the vessel, cause collapse Management: keep wire in the true lumen, restore flow Stent implantation is the usual treatment
- Tear through the wall; among the most feared events Leads to pericardial effusion and tamponade Management depends on severity of the perforation Severe: immediate balloon tamponade, then covered stent Less severe: prolonged inflation and monitoring Serial echocardiograms to detect tamponade
- Response to coronary perforation
- Occur during and after PCI Causes: reperfusion injury and myocardial ischaemia Also irritation from guidewires and catheters Common: bradycardia, ventricular tachycardia, AF Unstable rhythms: immediate defibrillation or cardioversion Stable patients: antiarrhythmics or beta-blockers
- Often results from cardiogenic shock Triggers: perforation, periprocedural MI, arrhythmia Immediate stabilisation with CPR if needed Pressors and inotropes to support circulation Support: percutaneous VAD or intra-aortic balloon pump Early recognition and a multidisciplinary approach
- Risks of Pci
- Management of Pci Complications
Post-procedure medical therapy
- Aspirin plus a P2Y12 inhibitor Clopidogrel, ticagrelor or prasugrel Prevents stent thrombosis, especially early after PCI Stent is thrombogenic until covered by endothelium Given with lipid lowering and GDMT for CAD
- SIHD with DES: at least 6 months, Class I Level A High bleeding risk: 3 months, Class IIa Level B ACS, STEMI and NSTE-ACS: at least 12 months Shorter if the bleeding risk is significant Duration individualised to ischaemic and bleeding risk
- Durations of Dapt Following Pci
- PEGASUS-TIMI 54 studied DAPT beyond one year Supported extension in high thrombotic risk patients Reduction in ischaemic events reported Guidelines: individualise the decision to extend Weigh ischaemic risk against bleeding risk
- Statins are the foundation of lipid-lowering therapy Class I for all patients after PCI Given regardless of baseline cholesterol level LDL-C goal below 55 mg/dL in high-risk individuals High-intensity atorvastatin or rosuvastatin preferred These reduce LDL-C by 50% or more
- Evolocumab and alirocumab added to statin therapy FOURIER and ODYSSEY OUTCOMES showed benefit Significant reduction in cardiovascular events For LDL-C persistently high on maximal statin Adjunct in high-risk patients missing LDL-C targets
- Beta-blockers plus ACE inhibitors or ARBs Reduce recurrent ischaemic events and symptoms Improve long-term outcomes Ejection fraction below 40%: Class I recommendation Add aldosterone antagonists in that group
- Pharmacotherapy for Post- Pci Patients
In-stent restenosis
- Neointimal tissue proliferates within the stent Causes recurrent luminal narrowing and ischaemia Feared complication after PCI More likely with complex lesions Also with suboptimal stent deployment Risk higher in diabetes and long stented segments
- Repeat PCI with balloon angioplasty, DCB or a second DES Laser atherectomy and cutting balloons as adjuncts Underexpanded stent: intravascular lithotripsy may help Lithotripsy modifies calcium outside the stent Then high-pressure non-compliant balloon expansion
- Avoid adding another layer of stent metal DAEDALUS supported DCB over repeat stenting AGENT-IDE supported DCB over uncoated balloon ESC Class IIa recommendation for DCB in ISR If DCB unsuitable, repeat newer-generation DES Use IVUS or OCT to confirm expansion and apposition
- Strategies for Managing In-Stent Restenosis
Future directions
- Focus on patients at high risk of bleeding GLOBAL LEADERS and TWILIGHT tested short DAPT Followed by ticagrelor or aspirin monotherapy Less major bleeding without more ischaemic events Shorter regimens now considered in high bleeding risk
- Alternative to stents in selected patients Useful in ISR and in small-vessel disease In small vessels a stent may itself obstruct flow PEPCAD-DES and DEBUT: promising reduction in restenosis Increasing adoption of the technique in Europe SELUTION trial studies sirolimus-coated balloons
- Designed to dissolve after supporting the artery Aim: avoid late thrombosis and restenosis of metal ABSORB and Magmaris are two notable devices ABSORB trials: more restenosis and thrombosis Newer generations under study for safety and efficacy
- PCI is a cornerstone of coronary artery disease care Advances in stents, imaging and technique improved outcomes PCI alone is not a definitive solution Needs optimal medical therapy and lifestyle change Multidisciplinary team care underpins long-term benefit Future emphasis on personalised, integrated strategies
- Numbers to carry from this topic
- Presentation decides the strength of the PCI indication In stable disease PCI relieves symptoms, not mortality Anatomy and diabetes push the decision toward CABG Radial access is the default; femoral for large bore Prepare the lesion before the stent, image the result Long-term outcome depends on drugs, not on the stent alone
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- Cardiovascular Catheterization and Intervention: A Textbook of Coronary, Peripheral, and Structural Heart Disease
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