What are the indications for coronary angiography in cardiology?

Indications for Coronary Angiography in Cardiology

Coronary angiography is indicated for patients with acute coronary syndromes, high-risk unstable angina, severe stable angina refractory to medical therapy, high-risk findings on non-invasive testing, and before valvular surgery in patients over 45 years old. 1

Class I Indications (Strongly Recommended)

Acute Coronary Syndromes

• ST-elevation myocardial infarction (STEMI) within 12 hours of symptom onset for primary percutaneous coronary intervention (PTCA), which is the treatment of choice 1, 2
• Cardiogenic shock complicating myocardial infarction 1, 3
• Mechanical complications of MI requiring surgical repair (ventricular septal defect, severe mitral regurgitation, large ventricular aneurysm with heart failure) 1, 3
• Failed thrombolysis or persistent ischemia after thrombolytic therapy 2
• Recurrent ischemia following myocardial infarction during the hospital phase 1

Unstable Coronary Syndromes

• High-risk unstable angina with objective evidence of ischemia despite optimal medical therapy 1
• Unstable angina with elevated cardiac biomarkers (creatine kinase isoforms) indicating poor prognosis 1
• Emergency cardiac catheterization for unstable angina with hemodynamic instability 1

Stable Coronary Artery Disease - High Risk Features

• Very high clinical likelihood (>85%) of obstructive CAD with severe symptoms refractory to antianginal treatment 1
• Characteristic angina or dyspnea at low exercise levels suggesting extensive obstructive CAD 1
• Canadian Cardiovascular Society (CCS) Class III angina despite good medical treatment 1, 3
• Angina in patients under 45 years old 4

High-Risk Non-Invasive Test Results

• CCTA showing ≥50% left main stenosis or ≥70% proximal LAD stenosis 1
• Stress testing demonstrating moderate to severe ischemia in single or two-vessel distribution, or ≥70% proximal three-vessel CAD 1
• Objective evidence of severe ischemia on exercise testing even with mild angina 4
• Positive stress ECG after myocardial infarction 4

Cardiac Arrest and Arrhythmias

• Out-of-hospital cardiac arrest survivors (sudden death syndrome unrelated to acute MI) 1, 3, 4
• Ventricular fibrillation requiring resuscitation 4
• Suspected Prinzmetal (variant) angina with arrhythmias 1, 4

Valvular Heart Disease

• Patients over 45 years old being considered for valve surgery (aortic, mitral, or other hemodynamically significant valvular disease) 1, 3, 4
• Preoperative assessment for aortic valve disease requiring corrective surgery 3

Heart Failure

• Unexplained congestive heart failure to evaluate for ischemic cardiomyopathy 1, 3
• Postinfarction aneurysm with signs of heart failure 4
• Left ventricular dysfunction suggesting extensive obstructive CAD 1

Congenital Heart Disease

• Anomalous left coronary artery 3
• Left-heart catheterization for hemodynamic assessment of congenital lesions 1

Class IIa Indications (Reasonable to Perform)

• Risk stratification phase after myocardial infarction with reduced ejection fraction 1
• Perioperative evaluation before or after noncardiac surgery in high-risk patients 1
• Uncertain results on non-invasive testing to confirm or exclude obstructive CAD 1
• Nonspecific chest pain with cardiac causes suspected after initial evaluation 1
• Dilated cardiomyopathy to exclude ischemic etiology 1

Class IIb/Uncertain Indications

• Silent ischemia with known CAD and risk factors 3
• Asymptomatic patients with abnormal stress ECG 4
• Evaluation of bypass surgery results 4
• Occupational hazard exposure with unclear diagnosis 4

Invasive Coronary Functional Testing (ICFT)

In patients with angina/ischemia with non-obstructive coronary arteries (ANOCA/INOCA), additional invasive testing should be performed including: 1

• Index of microcirculatory resistance (IMR) measurement
• Coronary flow reserve (CFR) assessment
• Invasive vasoreactivity testing with acetylcholine (or ergonovine) to detect microvascular angina (MVA) or vasospastic angina (VSA), which have a combined prevalence of approximately 80% in selected patients without obstructive CAD 1

Important Caveats

Radial access is now the standard approach when possible, as it reduces mortality, major bleeding, and allows rapid ambulation compared to femoral access (which has 0.5-2.0% major complication rate) 1. The composite rate of death, MI, or stroke with radial ICA is 0.1-0.2% 1.

Coronary pressure assessment (FFR/iFR) should be readily available to complement anatomic ICA findings, given the frequent mismatch between angiographic appearance and hemodynamic significance of stenoses 1.

Institutions performing at least 400 procedures annually achieve the lowest complication rates (mortality ~1%, MI 1.5-2%, cerebral embolism <1%) 4.