percutaneous transluminal coronary angioplasty (PTCA)

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
• patient not eligible for thrombolytic therapy
• myocardial infarction complicated by shock or CHF
• previous coronary artery bypass graft surgery
• failure of medical management following initial stabilization
• elective revascularization for 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)
• CABG is indicated for patients with diabetes mellitus who would otherwise be eligible for PTCA (better 5 year survival, 80% vs 65%)

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

Contraindications

• elective PTCA for one vessel disease does not:
  • reduce future risk of myocardial infarction
  • improve resting left ventricular function
  • increase survival
• 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

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

• 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
• IV nitroglycerin for management of angina.
• 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
• bivalirudin anticoagulation

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

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
• 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
  • continue aspirin 81 mg PO QD + clopidogrel 75 mg daily PO QD
• 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
• same day discharge after PTCA appears safe
• cardiac stress testing (stress echocardiography) after PCI may be appropriate
• routine electrocardiogram &/or cardiac stress testing in asymptomatic patients after successful PCI not indicated

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

More general terms

• percutaneous coronary intervention (PCI)
• angioplasty; balloon angioplasty
• coronary artery revascularization

More specific terms

• perfusion balloon angioplasty

Additional terms

• Bypass Angioplasty Revascularization Investivation (BARI)
• cardiac catheterization
• coronary artery bypass grafting (CABG)
• coronary stent/coronary stenting
• ISAR-REACT 2 trial
• Syntax trial
• TIMI study

Patient information

Percutaneous Transluminal Coronary Angioplasty (PTCA) patient information