Doctor123.org

Angina, Prinzmetal’s Variant Angina

Doctor123.org

Angina, Prinzmetal’s Variant Angina

Basics

Description

Histologic exam of coronary artery plaques reveals neointimal hyperplasia significantly more often in variant angina than in chronic stable exertional angina (68% vs. 8%). пїЅ

Volume resuscitation with saline if evidence of volume depletion пїЅ

Routine cardiac nursing care пїЅ

Low-fat, low-cholesterol diet, low-salt because 2/3 of coronary spasm occurs at site of angiographic atherosclerotic coronary lesion. пїЅ

Calcium antagonists in the treatment of Prinzmetal's angina and unstable angina pectoris. Circulation. 1989;80(Suppl IV):IV-78-IV-87. 2

Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine: Coronary Blood Flow and Myocardial Ischemia

Philadelphia: WB Saunders, 2008:1167-1177. 3

Variant angina. In: Rose пїЅBDWaltham MA: UpToDate, 2005. 4

Hong пїЅMK. Intravascular ultrasound findings of negative arterial remodeling at sites of focal coronary spasm in patients with vasospastic angina. Am Heart J. 2000;140:395-401. пїЅ[View Abstract] 5

Nakayama пїЅM, Yasue пїЅH, Yoshimura пїЅM. T-786 to C mutation in the 5"пїЅ-flanking region of the endothelial nitric oxide synthase gene is associated with coronary spasm. Circulation. 1999;99:2864. пїЅ[View Abstract] 6

Suzuki пїЅH, Kawai пїЅS, Aizawa пїЅT. Histologic evaluation of coronary plaque in patients with variant angina: Relationship between vasospasm and neointimal hyperplasia in primary coronary lesions. J Am Coll Cardiol. 1999;33:198. пїЅ[View Abstract]

87343002 prinzmetal angina (disorder) пїЅ

  • Variant angina is characterized by a transient, abrupt, marked reduction in the luminal diameter of an epicardial coronary artery which leads to symptomatic myocardial ischemia.
  • ST-segment elevation rapidly returns to baseline with relief of symptoms.
  • Exercise tolerance commonly preserved.
  • Symptoms often occur in early morning hours.
  • Most commonly occurs in right coronary artery, but can occur in left, and, less commonly, in coronary artery bypass grafts.
  • Synonym(s): Prinzmetal angina, cardiac syndrome X (angina pectoris with normal coronary arteries)
  • System(s) affected: Cardiovascular

Epidemiology

  • Patients younger than those with exertional angina
  • Other than tobacco use, classic cardiovascular risk factors uncommon
  • Associated with other vasospastic disorders
  • Substance abuse an important risk factor
  • Female predominance
  • Exact incidence unknown
  • Less common than exertional angina

Risk Factors

  • Smoking (#1 risk factor)
  • cocaine may precipitate vasospasm
  • Patients with pure vasospasm younger than patients with exertional angina (average age 48)
  • Female gender
  • Traditional coronary disease risk factors may be lacking.
  • Increased prevalence in certain geographic locations, including Canada, Italy, and Japan
  • Specific mutations in eNOS gene have significantly greater incidence in patients with variant angina compared with controls.
  • Defects in genes encoding for Kir6.1 or SUR2 greater in patients with variant angina than controls.

General Prevention

  • Avoidance of tobacco
  • Avoid cocaine use

Pathophysiology

  • Abnormalities of cardiac autonomic tone (particularly О±-adrenergic receptors)
  • Abnormal heart rate variability
  • Endothelial dysfunction
  • Adhesion molecules [leukocyte function-associated molecule-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1)]

Etiology

  • Transient coronary artery spasm, usually focal, with normal coronary anatomy or at site of atherosclerotic plaque. Coronary spasm may be contributing factor in development, progression of atherosclerosis.
  • Vasospasm superimposed on a fixed obstructive coronary heart disease (CHD) lesion has worse prognosis.
  • IVUS often demonstrates atherosclerotic plaque and intimal thickening in coronary arteries at site of spasm even in angiographically normal coronary arteries.
  • Thrombus may form at site of vasospasm.

Associated Conditions

  • Migraine headaches
  • Raynaud phenomenon
  • Ocular spasm
  • Aspirin-induced asthma
  • Churg-Strauss syndrome
  • Hyperthyroidism
  • Hypomagnesemia
  • Hyperinsulinemia

Diagnosis

History

  • Tobacco use
  • Cocaine use
  • Relationship to exercise
  • Hyperventilation

Physical Exam

  • Often unremarkable
  • A 4th heart sound can be present indicating ischemia.
  • CHF can occur in cases of significant ischemia with resultant LV dysfunction or ischemic mitral regurgitation.

Tests

  • ECG during pain and after relief of pain
  • Ambulatory ECG monitoring helpful in establishing diagnosis
  • Patient is at highest risk for sudden death or MI during acute, active phase of disease.
  • Treatment goal is prevention of coronary spasm.
  • Smoking cessation of paramount importance.
  • Control risk factors for atherosclerosis.
  • Avoid Cocaine use.
  • Medication compliance
  • Coronary angiography recommended
  • Consider provocative testing with ergonovine, which produces focal spasm in ~90% of patients (high sensitivity and specificity) with variant angina.
  • Provocative testing with intracoronary acetylcholine; low frequency of complications (0.6% incidence)
  • Exercise testing may provoke angina, ST elevation.
  • Dobutamine stress echo may provoke vasospasm in some patients with variant angina
  • Patients with positive hyperventilation test are more likely to have increased frequency of anginal attacks, multivessel spasm, AV block, ventricular tachycardia (sensitivity and specificity of 62% and 100%, respectively).

Differential Diagnosis

  • Angina pectoris
  • Pericarditis
  • Aortic dissection
  • Pulmonary processes, pulmonary embolism
  • GI disorders (particularly GERD)
  • Neurologic disorders
  • Musculoskeletal disorders
  • Psychiatric disorders

Treatment

Medication

  • Calcium channel blockers: >50% of patients become asymptomatic with calcium channel blocker therapy. Dihydropyridine and nondihydropyridine agents effective. High doses may be required. If symptoms not completely relieved with one drug, may be beneficial to add 2nd calcium channel blocker. Calcium channel blocker may decrease risk of MI.
  • Long-acting nitrates effective, but patients may develop tolerance.
  • Statins (fluvastatin 30 mg/d, most studied)
  • Sublingual nitrates indicated for acute episodes
  • Low-dose aspirin
  • >50% of patients become asymptomatic with calcium channel blocker therapy.
  • Dihydropyridine and nondihydropyridine agents effective.
  • High doses may be required.
  • If symptoms not completely relieved with one drug, may be beneficial to add 2nd calcium channel blocker.
  • Calcium channel blocker may decrease risk of MI.
  • Imipramine
  • Aminophylline
  • Contraindications: β-Blockers, nonselective agents in particular, may exacerbate vasospasm. Attacks may be provoked by 5-fluorouracil, cyclophosphamide. High-dose aspirin may exacerbate attacks by inhibiting coronary vasodilator prostacyclin.
  • Precautions: Calcium channel blocker withdrawal may cause rebound.
  • AHA recommends against menopausal hormone therapy, based on the Women's Health Initiative (WHI) and the Heart and Estrogen/Progestin Replacement Study-II (HERS-II)
  • β-Blockers, nonselective agents in particular, may exacerbate vasospasm.
  • Attacks may be provoked by 5-fluorouracil, cyclophosphamide.
  • High-dose aspirin may exacerbate attacks by inhibiting coronary vasodilator prostacyclin.
  • Calcium channel blocker withdrawal may cause rebound.

Additional Treatment

  • May be effective in refractory cases, but not approved for this use in the U.S.:
  • Amiodarone
  • Guanethidine
  • Prazosin
  • Clonidine
  • Corticosteroids
  • Close follow-up with cardiologist
  • Aggressive coronary risk factor modification
  • Smoking cessation program for tobacco users
  • Drug rehabilitation for illegal drug abusers

Surgery

  • Consider percutaneous transluminal coronary angioplasty (PTCA)/stenting for patients with significant fixed coronary lesions.
  • PTCA with stenting also used successfully in patients refractory to medical treatment without a fixed stenosis.
  • Recurrence rate of symptoms and angiographic disease after PTCA/stenting higher in patients with variant angina than stable angina
  • Reports of spasm recurring proximal to the stent
  • Reports of continued symptoms in occasional patients without objective evidence of spasm.
  • Other surgical options: Consider coronary artery bypass graft surgery in patients with significant multivessel disease. Surgical denervation and plexectomy have been used in refractory cases.
  • Consider coronary artery bypass graft surgery in patients with significant multivessel disease.
  • Surgical denervation and plexectomy have been used in refractory cases.

In-Patient Considerations

  • Unstable symptoms
  • Syncope
  • Malignant or symptomatic arrhythmias
  • MI
  • Resolution of chest pain and associated electrocardiographic changes
  • Referral for smoking cessation of paramount importance in outpatient setting.
  • Control risk factors for atherosclerosis.
  • Cessation of cocaine and other illegal drug use.

Ongoing Care

Follow-Up Recommendations

  • Monitor for relief of symptoms.
  • Telemetry
  • Ambulatory ECG monitoring helpful as some patients have silent attacks

Diet

Patient Education

  • Smoking cessation of utmost importance
  • Coronary risk factor control
  • Avoidance of cocaine
  • Compliance with medications

Prognosis

  • Arrhythmias or syncope during episodes increase risk of sudden death.
  • ST elevation in both inferior and anterior leads on ECG marker of increased risk of sudden death.
  • Predictors of poor outcome include extensive and severe coronary artery disease, abnormal LV function, absence of treatment with calcium channel blockers, continued tobacco abuse, and ventricular arrhythmias during episodes.
  • Acute active phase usually lasts 3-6 mo; then symptoms often remit.
  • In absence of underlying coronary atherosclerosis, once patient past acute active phase, chance of long-term survival is excellent (89-97%).

Complications

  • Sudden death, MI, ventricular arrhythmias, AV block, syncope
  • Greatest risk of adverse outcomes during acute, active phase of disease
  • Sudden death and MI occur most often during acute active phase.

Additional Reading

Codes

ICD9

SNOMED

Clinical Pearls

  • Female predominance
  • Substance abuse an important risk factor
  • In absence of underlying coronary atherosclerosis, overall long-term survival is excellent (89-97%).