What is the next test for patients with variant angina?

Diagnostic Approach for Variant Angina

The next test for patients with variant angina is coronary angiography, which is recommended to evaluate the coronary anatomy and guide treatment decisions. 1

Primary Diagnostic Strategy

Coronary angiography is the definitive next step for patients with episodic chest pain accompanied by transient ST-segment elevation, as it serves multiple critical purposes 1:

• Identifies the presence and severity of underlying coronary artery disease, which significantly impacts prognosis and treatment approach 1
• May capture spontaneous spasm during the procedure, which aids diagnosis even without prior documented ST-elevation 1
• Distinguishes between patients with normal/near-normal arteries versus those with obstructive disease, as 39% have single-vessel disease and 19% have multivessel disease 1

When Angiography Shows No Obstructive Disease

If coronary angiography reveals normal or nonobstructive coronary arteries and the diagnosis remains uncertain, provocative testing may be considered 1:

• Provocative testing with acetylcholine, ergonovine, or methacholine can be performed during angiography when coronary spasm is suspected but ST-elevation has not been documented 1
• This approach is Class IIb recommendation (Level of Evidence: C), meaning it may be considered in select cases 1
• Provocative tests should be considered specifically when attempts to document ST-elevation during pain have failed and the patient has episodes of angina at rest with negative exercise stress testing 1

Important Safety Considerations for Provocative Testing

Provocative testing is contraindicated (Class III) in patients with high-grade obstructive stenosis on coronary angiography due to safety concerns 1. The testing carries an acceptable but real risk:

• Arrhythmic complications occur in approximately 6.8% of cases, including ventricular tachycardia/fibrillation (3.2%) and brady-arrhythmias (2.7%) 2
• Nitrates and calcium channel blockers must be withdrawn well before provocative testing to avoid false-negative results 1
• Immediate intracoronary nitroglycerin must be available to promptly relieve induced spasm 1

Alternative Diagnostic Approaches Before Angiography

If coronary angiography is not immediately available or the diagnosis needs further documentation, consider these approaches:

• Continuous 12-lead ECG monitoring (in-hospital or ambulatory Holter) to capture transient ST-segment elevation during spontaneous chest pain episodes 1
• Exercise stress testing, though results are variable: one-third show ST-elevation, one-third show ST-depression, and one-third show no changes 1
• Testing is more often positive when performed in early morning hours, reflecting the circadian pattern of variant angina 1

Critical Clinical Context

The urgency and approach to angiography depends on the clinical presentation:

• Patients with documented transient ST-elevation during chest pain that resolves with nitroglycerin should proceed directly to coronary angiography 1
• The presence of syncope during chest pain episodes suggests severe ischemia from acute occlusion and warrants urgent evaluation 1
• Patients with normal or near-normal coronary arteries have excellent prognosis (95% 5-year survival), while those with multivessel disease have worse outcomes (80% 5-year survival) 1