What are the indications, contraindications, merits, and demerits of coronary angiography in adults with symptoms of coronary artery disease?

Coronary Angiography: Indications, Contraindications, Merits, and Demerits

Coronary angiography should be performed in patients with stable ischemic heart disease who have unacceptable symptoms despite optimal medical therapy and are candidates for revascularization, as well as in heart failure patients with angina or significant ischemia. 1

Primary Indications

Class I (Definitive) Indications

• Patients with presumed stable ischemic heart disease experiencing unacceptable symptoms (chest pain limiting activity or quality of life) despite guideline-directed medical therapy who are amenable to revascularization. 1
• Heart failure patients presenting with angina or significant ischemia, unless they are ineligible for any form of revascularization. 1

Class IIa (Reasonable) Indications

• Patients with suspected stable ischemic heart disease whose clinical characteristics and noninvasive testing results (excluding stress tests) indicate high likelihood of severe disease and who are revascularization candidates. 1
• Symptomatic patients who cannot undergo diagnostic stress testing, or have indeterminate/nondiagnostic stress tests, when findings will result in important therapy changes. 1
• Heart failure patients with chest pain of uncertain cardiac origin who have not had coronary anatomy evaluation and have no contraindications to revascularization. 1
• Heart failure patients with known or suspected coronary disease but without angina, unless ineligible for revascularization. 1

Class IIb (May Be Considered) Indications

• Patients with acceptable-quality stress tests showing no coronary disease when clinical suspicion remains high and findings will result in important therapy changes. 1

Specific Clinical Scenarios Warranting Angiography

• Ascertain the cause of chest pain or anginal equivalent symptoms. 1
• Define coronary anatomy in patients with high-risk noninvasive stress test findings as prerequisite for revascularization. 1
• Determine whether severe coronary disease causes depressed left ventricular ejection fraction. 1
• Assess for possible ischemia-mediated ventricular arrhythmias. 1
• Evaluate cardiovascular risk in solid-organ transplantation candidates (recipients and donors). 1
• Patients with long-standing diabetes with end-organ damage, severe peripheral vascular disease, or previous chest radiation therapy when ischemic symptoms are present. 1
• Patients with typical angina combined with transient heart failure, pulmonary edema, or exertional/unheralded syncope. 1

Relative Contraindications and High-Risk Patient Groups

There are no absolute contraindications when angiography is clinically necessary, but risks must be carefully weighed against benefits in specific populations. 1

High-Risk Patient Characteristics

• Advanced age (>70 years). 1
• Marked functional impairment (Canadian Cardiovascular Society class IV angina or NYHA class IV heart failure). 1
• Severe left ventricular dysfunction or severe coronary artery disease (particularly left main disease). 1
• Severe valvular disease. 1
• Severe comorbid medical conditions (renal, hepatic, or pulmonary disease). 1
• Bleeding disorders. 1
• History of allergic reaction to radiographic contrast material. 1
• Renal insufficiency or diabetes mellitus (increased risk of contrast-induced nephropathy). 1

Merits of Coronary Angiography

Diagnostic Advantages

• Remains the gold standard for evaluating coronary artery disease despite emergence of newer modalities like CT angiography, intravascular ultrasound, and MR angiography. 2
• Provides definitive exclusion of significant epicardial coronary disease, which is particularly valuable when it leads to appropriate treatment changes, including withdrawal of unnecessary medications. 1
• Allows simultaneous performance of left ventriculography and aortography for comprehensive cardiac evaluation. 2
• Enables direct assessment of coronary anatomy as prerequisite for revascularization decisions. 1

Therapeutic Integration

• Permits immediate fractional flow reserve (FFR) assessment of hemodynamically intermediate lesions (40-90% stenosis) to determine if percutaneous coronary intervention should be performed or safely deferred. 1
• FFR-guided PCI strategy has been suggested in several studies to be superior to angiography-guided strategy alone. 1
• Allows adjunctive intravascular ultrasound and optical coherence tomography for more precise stenosis severity and plaque morphology assessment than angiography alone. 1

Demerits and Limitations of Coronary Angiography

Technical Limitations

• Angiographic stenosis severity assessment relies on comparison to adjacent nondiseased reference segments; in diffusely diseased coronary arteries, lack of normal reference may lead to underestimation of lesion severity. 1
• Significant interobserver variability exists in grading coronary stenosis, with visual assessment overestimating disease severity when stenosis is ≥50%. 1
• Many stenoses considered severe by visual assessment (≥70% luminal narrowing) do not restrict coronary blood flow at rest or with maximal dilatation, while others considered insignificant (<70% narrowing) are hemodynamically significant. 1
• Cannot assess whether atherosclerotic plaque is stable or vulnerable (likely to rupture and cause acute coronary syndrome). 1
• Quantitative coronary angiography, though more accurate than visual assessment, is rarely used clinically because it does not accurately assess physiological significance of lesions. 1

Procedural Complications

• Overall procedural complication rate of 1.5% according to ACC's National Cardiovascular Data Registry CathPCI Registry (2012 data). 1
• Specific complications include death, stroke, myocardial infarction, bleeding, infection, contrast allergic or anaphylactoid reactions, vascular damage, contrast-induced nephropathy, arrhythmias, and need for emergency revascularization. 1

Clinical Yield Concerns

• Among patients undergoing elective catheterization, 21% had normal coronary arteries (no lesions ≥20%), with median proportion ranging from 10.8% in lowest quartile hospitals to 30.3% in highest quartile hospitals. 1
• Even among patients with positive noninvasive test results, only 41% were found to have significant coronary disease. 1
• Angiographically normal or near-normal coronary arteries are more common among women, who are more likely to have myocardial ischemia due to microvascular disease. 1

Critical Pitfalls to Avoid

• Do not perform angiography in asymptomatic patients after treatment without specific high-risk features (elevated troponin, hemodynamic instability, major arrhythmias, dynamic ST-segment changes), as revascularization has not been shown to improve clinical outcomes in asymptomatic patients. 3
• Do not assume symptom absence equals low risk in diabetic patients, who may have silent ischemia despite significant coronary disease. 3
• Do not repeat coronary evaluation without new clinical developments suggesting interim disease progression. 3
• The concept of informed consent requires that risks, benefits, and alternatives to coronary angiography be explicitly discussed with patients before the procedure, particularly in high-risk groups. 1
• In deciding whether to perform angiography in high-risk patients, balance procedural risks against the increased likelihood of finding critical coronary disease. 1