Author:
Jamie L.Adler
Shamai A.Grossman
Description
- Spontaneous episodes of chest pain due to coronary artery vasospasm in the absence of increase in myocardial oxygen demand in either normal or diseased coronary vessels
- Also known as Prinzmetal angina or variant angina, originally described in 1959
- Most common in younger patients and men
- Usually occurs in patients without cardiac risk factors or coronary artery disease but may occur concurrently with obstructive coronary artery disease
- 12-mo major cardiac events in patients with myocardial infarction (MI) secondary to vasospasm is comparable to AMI with single- or double-vessel disease
- Risk factors:
- Smoking (up to 75% of cases)
- Hypertension
- Hypercholesterolemia
- Diabetes mellitus
- Cocaine use
Etiology
- Abnormal vasodilator function in coronary arteries typically endothelial in origin
- High prevalence of microvascular and epicardial vessel involvement
- Defined by 3 types:
- Focal: Localized, often at or near a site of stenosis of a single artery
- Multifocal: 2 or more segments of the same artery
- Multivessel: Involving different coronary arteries
- Can occur in the absence of preceding increased oxygen demand
- Unopposed α-sympathetic stimulation
- Sympathetic stimulation by endogenous hormones with hyperreactivity can cause vasoconstriction
- Conversely, also associated with increased vagal tone or withdrawal from vagal tone as proven with acetylcholine provocative testing
- Hypersensitivity of coronary arteries due to mediators of vasoconstriction
- Endothelial dysfunction possibly from genetic mutations in nitric oxide synthase
- Newer research suggests potential increase in ρ-kinase activity in smooth muscle cells
Signs and Symptoms
- Chest pain or discomfort:
- Retrosternal
- Radiates to neck, jaw, left shoulder, or arm
- Occurs at rest
- Occurs more frequently at night or in the morning
- Not associated with position
- May be associated with diaphoresis, nausea, vomiting, dizziness
- Palpitations
- Presyncope or syncope
- Associated with migraine headaches and Raynaud disease in a minority of patients
- May occur during cold weather or stress
- May be prolonged in duration compared with typical angina
- May be elicited by hyperventilation
- May be elicited by exercise
- Circadian pattern, typically at night or early morning when vagal tone is higher
- Coronary Vasomotor Disorders International Study Group (COVADIS) diagnostic criteria:
- Nitrate-responsive angina
- Transient ischemic ECG changes
- Angiographic evidence of high-grade transient coronary artery spasm
History
May mimic angina; occurrences in the early morning should raise suspicion for vasospasm, but also ask about relationship to stress, exercise, and cold weather
Physical Exam
Physical exam is typically nondiagnostic.
Essential Workup
- Must include an ECG
- Use of other tests depends on history
Diagnostic Tests & Interpretation
- ECG:
- Transient ST-segment elevation is characteristic, is typically quite pronounced
- Often with reciprocal changes
- May be followed by ST depression or T-wave inversion
- May have associated dysrhythmia during coronary spasm
- Heart block with right coronary artery spasm
- Ventricular tachycardia with LAD spasm
- In rare cases can present with sudden death during prolonged vasospasm period
Lab
- Troponin
- CK/CK-MB fraction
- Toxicology screen:
- Helpful if cocaine is suspected as etiology of chest pain
Imaging
- CXR:
- Noninvasive coronary imaging (nuclear perfusion, coronary CTA, coronary MR)
- Typically only helpful when combined with provocative testing
Diagnostic Procedures/Surgery
- Exercise stress testing:
- Usually not helpful, but can help define those with true ischemic disease
- Noninvasive provocative hyperventilation:
- Highly specific, moderately sensitive, tends to favor those with increased disease activity
- Paired with either ECG or ECG plus perfusion imaging
- Holter monitor:
- Can be helpful in silent cases or dysrhythmia
- Cardiac magnetic resonance imaging:
- May identify the underlying cause in as many as 87% of patients
- Coronary angiography:
- Mild atherosclerosis is often the norm
- Provocative test with acetylcholine is the gold stand ard
Differential Diagnosis
- Angina pectoris
- Anxiety and panic disorders
- Aortic dissection
- Cocaine chest pain
- Esophageal rupture
- Esophageal spasm
- Esophagitis
- GERD
- Mitral valve prolapse
- Musculoskeletal chest pain
- MI
- Peptic ulcer disease
- Pericarditis
- Pneumothorax
- Pulmonary embolism
- Takotsubo cardiomyopathy
Prehospital
Treat as any other acute coronary syndrome.
Initial Stabilization/Therapy
- IV access
- Oxygen
- Cardiac monitoring
- Vital signs and oxygen saturation
ED Treatment/Procedures
- All patients with chest pain in which cardiac ischemia is a consideration should receive an aspirin upon arrival to the ED:
- Paradoxically may increase severity of Prinzmetal angina due to inhibition of biosynthesis of naturally occurring coronary vasodilator—prostacyclin.
- Nitroglycerin should still be administered and usually will help relieve both ischemic and vasospastic chest pain.
- A trial of calcium channel blockers is indicated if clinical history is consistent with coronary vasospasm.
- Heparin and β-blockers are not helpful in true coronary vasospasm:
- β-Blockers may be detrimental due to unopposed α-mediated vasoconstriction and should be avoided in suspected cocaine chest pain.
Medication
- Aspirin: 325 mg PO
- Diltiazem: 240-360 mg PO daily
- Nitroglycerin, either:
- 0.4 mg sublingual
- 10-20 mcg/min IV; USE NON-PVC tubing, titrating to effect
- 1-2 in of nitro paste
- Verapamil: 40-80 mg PO (immediate release)
First Line
- Diltiazem/verapamil:
- >40% of patients will have recurrence of vasospastic angina despite calcium channel blocker therapy
- Long-acting nitrates
Second Line
- α-Blocking agents
- Statin therapy
- Percutaneous intervention with stenting of fixed lesions in area of vasospasm controversial; can lead to spasm in other areas of coronary tree
- Pacemaker placement for patients with recurrent syncope or AV nodal block from vasospastic angina
Disposition
Admission Criteria
- New-onset chest pain
- Rule-in with positive biochemical markers or provocative testing
- Rule-in with positive biochemical markers or stress testing
- Many patients previously admitted to the hospital can now be effectively evaluated in a chest pain observation unit or clinical decision unit
Discharge Criteria
- Stable (chronic chest pain)
- Negative ischemic workup
Follow-up Recommendations
- Cardiology follow-up within 7 d of ED evaluation
- Smoking cessation education
- JCS Joint Working Group. Guidelines for diagnosis and treatment of patients with vasospastic angina (Coronary Spastic Angina) . Circ J. 2014;78:2779-2801.
- LindahlB, BaronT, ErlingeD, et al. Medical therapy for secondary prevention and long-term outcome in patients with myocardial infarction with nonobstructive coronary artery disease . Circulation. 2017;135:1481-1489.
- NiccoliG, ScaloneG, CreaF. Acute myocardial infarction with no obstructive coronary atherosclerosis: mechanisms and management . Eur Heart J. 2015;36:475-481.
- OngP, AzizA, HansenHS, et al. Structural and functional coronary artery abnormalities in patients with vasospastic angina pectoris . Circ J. 2015;79:1431-1438.
- PasupathyS, TavellaR, BeltrameJF. Myocardial infarction with nonobstructive coronary arteries (MINOCA): The past, present, and future management . Circulation. 2017;135:1490-1493.
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