Indications for Coronary Angioplasty
Angioplasty is indicated for patients with significant coronary stenosis (≥50% diameter reduction) who have either persistent ischemic symptoms despite medical therapy, objective evidence of severe myocardial ischemia on stress testing, or life-threatening arrhythmias, provided the lesion subtends at least a moderate-sized area of viable myocardium and the patient is at low-to-moderate procedural risk. 1
Single-Vessel Coronary Disease
Class I (Strongly Indicated)
Angioplasty is definitively indicated for patients with a significant lesion in a major epicardial artery subtending at least a moderate-sized area of viable myocardium who meet any of the following criteria: 1
Evidence of myocardial ischemia while on medical therapy, defined as ≥1mm ST depression on ECG monitoring at rest, exercise-induced ischemia with ≥1mm ST depression, stress-induced reversible perfusion defects, or exercise-induced wall motion abnormalities 1
Angina inadequately responsive to medical treatment, meaning symptoms significantly interfere with occupation or usual activities despite optimal medical therapy 1
Intolerance to medical therapy due to uncontrollable side effects 1
Class II (Reasonable to Consider)
Angioplasty may be reasonable in asymptomatic or mildly symptomatic patients with single-vessel disease when: 1
The patient's occupation involves public safety (airline pilots, bus drivers, air-traffic controllers) or requires sudden vigorous activity (firefighters, police officers) 1
The patient has borderline lesions (50-60% stenosis) with documented inducible ischemia on stress testing 1
Class III (Not Indicated)
Angioplasty should not be performed in single-vessel disease patients who: 1, 2
Have only a small area of viable myocardium at risk, even with moderate or severe ischemia 1, 2
Show no objective evidence of myocardial ischemia during high-level stress testing (≥12 METS) 1
Have symptoms not likely indicative of ischemia 1
Are at high risk for procedural morbidity or mortality 1
Critical Pitfall: The amount of myocardium at risk is more important than the degree of stenosis or ischemia severity—moderate ischemia in a small territory does not warrant intervention. 2
Multivessel Coronary Disease
Class I (Strongly Indicated)
For multivessel disease, angioplasty is indicated in: 1
Asymptomatic or mildly symptomatic patients with severe myocardial ischemia on stress testing who can achieve nearly complete revascularization and are at low procedural risk 1
Patients resuscitated from cardiac arrest or sustained ventricular tachycardia in the absence of acute MI, with lesions amenable to complete revascularization 1
Patients undergoing high-risk noncardiac surgery with objective evidence of myocardial ischemia 1
Key Consideration for Multivessel Disease
Each lesion must be evaluated in the context of all other lesions present—assess the hemodynamic consequences if any attempted dilation fails and results in abrupt vessel closure. 1 For example, do not attempt dilation of a proximal LAD lesion if it supplies collaterals to a large area of viable myocardium in the distribution of a totally occluded dominant RCA. 1
Post-Myocardial Infarction Setting
Class I (Strongly Indicated)
Angioplasty is indicated in the post-MI period for patients with: 1
Recurrent postinfarction angina with ECG changes 1
Severe myocardial ischemia on predischarge stress testing 1
Recurrent sustained ventricular tachycardia or ventricular fibrillation despite intensive antiarrhythmic therapy 1
All must have lesions predicting >90% success rate and be at low procedural risk. 1
Class II (Reasonable to Consider)
Consider angioplasty for: 1
Patients similar to Class I but with more complex lesion morphology (Type B lesions) or at moderate procedural risk 1
Patients within the very early hours of evolving MI, with or without thrombolytic therapy 1
Patients within 12 hours of cardiogenic shock onset or survivors of cardiogenic shock before discharge 1
Non-Q wave MI patients with significant residual lesions in the infarct-related artery 1
Class III (Not Indicated)
Do not perform angioplasty in the immediate post-MI period for: 1
Dilation of non-infarct-related arteries within 0-6 hours of infarction 1
Borderline residual lesions (50-60% stenosis) without spontaneous or inducible ischemia 1
Chronic total occlusions subtending nonviable myocardium 1
Type C lesions or patients at high procedural risk 1
Important Note: Multiple randomized trials demonstrate that routine immediate angioplasty after thrombolytic therapy should be deferred—angioplasty is only indicated for failed thrombolysis (rescue angioplasty) or recurrent ischemia. 1, 3
Risk Stratification Framework
Success is defined as ≥20% improvement in luminal diameter with final stenosis ≤30%, without death, acute MI, or emergency bypass surgery during hospitalization. 1
Low-risk patients have simple lesion morphology (Type A), good ventricular function, and single-vessel disease. 1
Moderate-risk patients have more complex lesions (Type B), multivessel disease requiring complete revascularization, or mild ventricular dysfunction. 1
High-risk patients include those with severe left ventricular dysfunction (EF ≤35%), Type C lesions, or lesions where failure would result in severe hemodynamic collapse. 1, 4 While angioplasty can be performed in severe LV dysfunction with 90% clinical success, acute complications are more frequent (8.2%) and late mortality is higher than in patients with preserved function. 4