percutaneous coronary intervention (PCI)

Introduction

An invasive procedure to enlarge the lumen of a narrowed coronary artery by balloon compression. The angioplasty catheter is inserted into a coronary artery, & the cylindrical balloon is inflated at the site of an obstructing atheroma.

Indications

• primary therapy for unstable angina with ST segment elevation* (see CAPITAL AMI study, STEMI)
• rescue therapy
  • following failed thrombolysis
  • persistent hemodynamic instability or arrhythmia
  • 60-90 minutes* after initiation of thrombolytic therapy
• unstable angina
  • patient not eligible for thrombolytic therapy
• myocardial infarction
  • complicated by cardiogenic shock or CHF
  • failure of medical management following initial stabilization
• restenosis of previous coronary artery bypass graft
• elective revascularization for ischemic heart disease due to coronary artery disease
  • impaired left ventricular function
    • 2 or more vessels with > 50% stenosis
      • CABG preferred for multivessel disease with reduced LV ejection fraction
    • viable left ventricular myocardium with abnormal wall motion
  • normal left ventricular function with left main, 3-vessel or severe 2-vessel disease
  • proximal left anterior descending artery disease
    • common clinical practice, improves quality of life
    • exception to the single vessel contraindication (MKSAP18)
• new onset acute heart failure or cardiogenic shock

* may be better than thrombolysis for primary therapy see 'PTCA vs thrombolysis for acute MI

* 3-24 hours after thrombolytic therapy in asymptomatic patients

# PCI for STEMI in patients with diabetes mellitus #CABG for failed PCI or thrombolytic therapy after STEMI #CABG in with diabetes mellitus otherwise be eligible for PCI (better 5 year survival, 80% vs 65%)

Contraindications

• elective PCI for one vessel disease or chronic stable angina* does not:
  • reduce future risk of myocardial infarction
  • improve resting left ventricular function
  • increase survival
  • either PCI or CABG reasonable for left main coronary artery disease
• routine thrombectomy with PCI of no benefit (see thrombectomy)
• late PCI to restore perfusion of infarcted myocardium of no benefit.
• preventive PCI in stable coronary disease of no benefit
• PCI for stable occluded coronary artery disease of little to no benefit
• late PCI for totally occluded coronary artery after myocardial infarction of no benefit
• PCI no better than medical therapy for stable coronary artery disease with proven myocardial ischemia
• acute coronary syndrome or NSTEMI
• patients without hemodynamically significant coronary artery stenosis have favorable long-term prognosis with medical therapy alone

* for some patients with chronic stable angina & coronary ischemia, elective PCI can provide meaningful symptomatic relief & functional benefits

Benefit/risk

• PCI for acute coronary syndrome or NSTEMI
  • no mortality benefit
  • risk for MI higher for PCI than medical management
  • number needed to treat (NNT) to reduce severity of angina pectoris = 9

Laboratory

• reperfusion is associated with higher peak serum CK-MB than persistent occlusion
• platelet-function testing may be clinically relevant for a small proportion of patients
  • high platelet reactivity confers risk of stent thrombosis

Procedure

• radial artery vs femoral artery access exposes patients to a bit more but operators to a lot more radiation (77 vs 41 microsieverts at the level of the chest)
  • still radial artery access recommended for PCI
• loading dose of clopidogrel 600 mg, followed by 150 mg/day for 6 days, then 75 mg/day
  • add aspirin 81 mg QD if coronary stenting
• systemic anticoagulation
  • bivalirudin anticoagulation
  • heparin 70 U/kg is superior to bivalirudin
  • bivalirudin vs unfractionated heparin at the time of PCI roughly equivalent
• IV nitroglycerin for management of angina
• intravascular imaging vs coronary angiography for visualizing coronary artery anatomy
• eptifibatide (Integrilin) for 12 hours after PTCA
• coronary stenting may reduce the rate of restenosis
• treatment with abciximab with PTCA & coronary stenting may further reduce the rate of restenosis (10% at 6 months)
• facilitated PCI with reteplase plus abciximab or abciximab alone started early before PCI did improve outcomes, compared with primary PCI in STEMI patients
• intracoronary abciximab (0.25 mg/kg), delivered into the thrombus region with an infusion catheter
• manual aspiration thrombectomy with the Export catheter in patients with as large thrombus
  • routine thrombus aspiration before PCI in patients with STEMI of no benefit
  • routine thrombectomy of no benefit & may result in an increased 30 day risk of stroke (0.7% vs 0.3%)
• fractional flow reserve (FFR) guidance should be standard of care for most patients with multivessel disease
  • single vessel fractional flow reserve (FFR) guidance of benefit
• complete multivessel revascularization at the time of PCI in patients with acute myocardial infarction who present with cardiogenic shock
  • fewer early complications & lower mortality with culprit vessel only revascularization
  • culprit vessel only revascularization associated with lower 1-year mortality if culprit lesion located in the left main coronary artery or proximal left anterior descending artery but not other coronary arteries
• in patients with STEMI & multivessel CAD, complete revascularization increases likelihood of freedom from angina vs culprit-lesion only strategy
• complete revascularization reduces death, MI, stroke, or repeat revascularization within 1 year vs culprit vessel only for STEMI or NSTEMI (RR=0.73, NNT=20)

Complications

• contrast nephropathy
• 30-45% restenosis within 6 months (20% in)
• patients with atrial fibrillation requiring warfarin plus clopidogrel plus aspirin at high risk of hemorrhage
• pseudoaneurysm or arteriovenous fistula at the site of catheter insertion
  • duplex ultrasound to distinguish
• stent thrombosis may occur in patients with high platelet reactivity
• accelerated idioventricular rhythm (ventricular tachycardia) is common following coronary reperfusion & does not require intervention when it occurs within the 1st 24 hours
  • heart rate < 120/min, usually < 100/min
• device approved for treatment of acute coronary artery perforations during PCI

Management

• PCI should be performed ASAP (as soon as possible)
  • PCI should be performed within 90 minutes of medical contact
  • symptom onset to procedure time more important than door to procedure time (door to balloon time)
  • PCI within 2 hours of symptom onset leads to better outcomes
• revascularization of non-infarct-related arteries in STEMI results in improved outcomes
  • revascularization on non-infarct-related arteries after STEMI determined by fractional flow reserve associated with diminished need for revascularization (6.1% vs 17.5%) but not all-cause mortality (1.4% vs 1.7%)
• complete revascularization vs culprit artery only PCI in patients with multivessel disease reduces cardiovascular death & myocardial infarction
  • benefits of revascularization during same procedure vs shortly after not established
• antiplatelet therapy
  • clopidogrel 600 mg prior to procedure or cangrelor 30 ug/kg bolus & 4 ug/kg infusion followed by 600 mg of clopidogrel at termination of infusion
  • pretreatment with P2Y12 inhibitor (clopidogrel, ticagrelor)
    • prasugrel for STEMI prior to PCI but deferred until after PCI for NSTEMI & other acute coronary syndromes (superior to routine ticagrelor)
    • 16% reduction in major cardiovascular events
    • 32% increase in major bleeding
    • no change in mortality
  • dual anti-platelet therapy (DAPT) after PCI
    • 1-3 months sufficient
      • lower bleeding risk with 3 months DAPT than 6 months in elderly without difference in major cardiovascular events
      • 1 month of DAPT after PCI for acute coronary syndrome inadequate
      • 1 month of DAPT after PCI with biodegradable-polymer sirolimus-eluting coronary stent may be sufficient in high-risk patients
    • aspirin 81 mg PO QD + clopidogrel 75 mg daily PO QD
    • addition of aspirin 81 mg to ticagrelor for 1-12 months after PCI for acute coronary syndrome of no benefit
    • continue P2Y12 inhibitor for 6-12 months
  • clopidogrel superior to aspirin or ticagrelor for long-term monotherapy
    • MKSAP19 disagrees, aspirin indicated vs clopidogrel
  • higher cost of prasugrel & ticagrelor vs clopidogrel associated with increased nonfilling of prescriptions
  • prasugrel contraindicated in patients with history of stroke
  • no benefit to glycoprotein inhibitors as adjunctive treatment to PCI for patients with STEMI
• P2Y12 inhibitor + direct oral anticoagulant if atrial fibrillation
  • for older adults with atrial fibrillation & acute MI who undergo PCI, treatment with dual antiplatelet therapy (DAPT) plus warfarin (triple therapy) of no benefit over DAPT alone & may increase risk of bleeding
  • ACC recommends P2Y12 inhibitor + direct oral anticoagulant (omit aspirin) if atrial fibrillation
  • dabigatran 110 mg BID + clopidogrel or ticagrelor (no aspirin) noninferior to triple therapy with respect to thromboembolic events with lower risk of bleeding
• beta-blocker of no benefit in older patients without myocardial infarction
• ranolazine of no benefit for patients with incomplete revascularization after PCI
• atorvastatin 80 mg before & 24 hours after PCI followed by 40 mg PO QD does not reduce major cardiovascular events at 30 days
• combination B vitamins for 6 months
  • folate 1 mg, vitamin B12 400 ug, vitamin B6 10 mg PO QD
  • reduces serum homocysteine
  • reduced combined endpoint: myocardial infarction, death, restenosis (revascularization) {15% vs 23%}
  • in other settings, the combination of folate, vitamin B6, & vitamin B12 have not been foun to reduce cardiovascular mortality
• intraluminal radiation, beta-radiation (18 Gy) or gamma-radiation may also reduce rate of restenosis, including those with restenosis after stenting
• cyclosporine prior to PCI of no benefit in patients with anterior wall STEMI
• delay placement of ICD until patient has recovered & medical therapy has been optimized
• same day discharge after PTCA appears safe
• delay non-cardiac surgery for 14 days (no coronary stent)
• cardiac stress testing (stress echocardiography) after PCI may be appropriate
• routine electrocardiogram, cardiac stress testing or angiography (invasive or CT angiography) in asymptomatic patients after successful PCI not indicated
• avoid smoking marijuana after PCI
  • increased risk of recurrent myocardial infarction or stroke

Notes

• angioplasty would appear superior to streptokinase thrombolysis in the treatment of myocardial infarction, but requires expertise not yet available at many hospitals
• elective PTCA for multivessel disease has a slightly higher mortality than CABG
  • at 1 year (5% vs 4%)
  • at 5 years (16% vs 14%)
• CABG is superior to PCI for
  • severe coronary artery disease; see Syntax trial
  • patients with diabetes mellitus
  • patients > 65 years of age
  • left main coronary artery disease
  • multivessel coronary artery disease with involvement of left anterior descending coronary artery (LAD) & reduced LV ejection fraction
• facilitated percutaneous intervention is the use of pharmaceutical agents before a planned intervention
  • mixed results
  • pretreatment with clopidogrel decreased combined incidence of sudden death, myocardial infarction & stroke associated with PTCA in patients with STEMI. (4% vs 6%)
  • offered no benefit, outcomes may be worse
  • would be to become standard of care
• combination of pretreatment with clopidogrel + treatment with abciximab + heparin (during or after procedure) may be of benefit in patient with non-STEMI (see ISAR-REACT 2 trial)
• prasugrel in combination with aspirin may be an option for patients with
  • stent thrombosis during clopidogrel treatment
  • diabetes mellitus (NGC, NICE)
• percutaneous coronary intervention at hospitals without on-site cardiac surgery are noninferior to those at hospitals with on-site surgery
• outcomes independent of procedure appropriateness
• public reporting of acute MI outcomes is associated with
  • lower PCI use, particularly in high-risk patients
  • higher overall in-hospital mortality, mostly in patients who do not undergo PCI

More general terms

• interventional radiology
• cardiac catheterization

More specific terms

• percutaneous transluminal coronary angioplasty (PTCA)

Additional terms

• Bypass Angioplasty Revascularization Investivation (BARI)
• coronary stent/coronary stenting
• ISAR-REACT 2 trial
• percutaneous coronary intervention (PCI)/coronary stent vs CABG
• Syntax trial
• TIMI study

Patient information

percutaneous coronary intervention patient information