ANGINA

ANGINA - Philip P. Lobstein, MD
BASICS
DESCRIPTION
• Symptom complex resulting from mismatch of myocardial oxygen demand and supply:
- Classic angina: A sense of choking or of pressure or heaviness deep to the precordium, usually brought on by exertion or anxiety and relieved by rest
- Anginal equivalent: Exertional dyspnea or exertional fatigue, which results from myocardial ischemia and is relieved by rest or nitroglycerin
- Variant angina: Also referred to as Prinzmetal angina; describes angina occurring at rest in atypical patterns such as after exercise or nocturnally. Prinzmetal angina is caused by coronary artery spasm, and is associated with ECG changes (usually ST elevation) during symptoms
- Stable angina: Predictable chest discomfort that occurs in a consistent pattern at a certain level of exertion and is relieved with rest or nitroglycerin
- Unstable angina: Pain that is new or is changed in character to become more frequent, more severe, or both. Unstable angina portends myocardial infarction in a certain percentage of patients.
• System(s) Affected: Cardiovascular
• Synonym(s): Heberden syndrome
ALERT
Geriatric Considerations
Patients may be very sensitive to the side effects of the medications.
Pediatric Considerations
Suspect familial dyslipidemias in children presenting with manifestations of coronary artery disease.
Pregnancy Considerations
Other diagnoses should be excluded, and the patient managed closely by an obstetrician or family physician and cardiologist: The metabolic demands of pregnancy will exacerbate symptoms and directly interfere with treatment.
GENERAL PREVENTION
• Discontinue tobacco, adherence to low fat/low cholesterol diet, regular aerobic exercise program
• Antilipidemics if indicated by current ATP guidelines
• Daily aspirin in those without contraindications
EPIDEMIOLOGY
• Predominant age: Most common in middle age and older men; postmenopausal women
• Predominant sex: Male > Female (before menopause)
Incidence
Presenting symptom of coronary artery
• Male: 38%
• Female: 61%
RISK FACTORS
• Family history of premature coronary artery disease (CAD)
• Hypercholesterolemia
• Hypertension
• Tobacco abuse
• Diabetes mellitus
• Male gender
• Advanced age
• Morbid obesity
• Hyperhomocysteinemia (possibly)
Genetics
Coronary artery disease has genetic implications.
ETIOLOGY
• Atherosclerosis of the coronary arteries
• Coronary artery spasm
• Aortic stenosis
• Hypertrophic cardiomyopathy
• Severe hypertension
• Aortic insufficiency
• Primary pulmonary hypertension
ASSOCIATED CONDITIONS
• Hypercholesterolemia
• Claudication, Peripheral vascular disease
• Arterial aneurysms
• Mitral regurgitation
• Papillary muscle dysfunction
• Ventricular aneurysm
• Abdominal aortic aneurysm
• Hypertrophic subaortic stenosis
• Primary hyperthyroidism
• Pernicious anemia and other high output states


DIAGNOSIS
SIGNS AND SYMPTOMS
• Precordial pressure or heaviness, radiating to the back, neck, or arms; brought on by exertion, emotional stress, meals, cold air, or smoking; and relieved by rest or nitrates
• Discomfort may radiate to the neck, lower jaw, teeth, shoulders, and inner aspects of the arms or back.
• Discomfort may be described with a clenched fist over the sternum (Levine sign).
• Dyspnea on exertion may present as the only symptom.
• A choking sensation on exertion is a classic symptom.
• Atypical symptoms are more likely in women, elderly, and diabetic patients.
History
• Quality of any previous anginal episodes and pattern over time
• Underlying history of heart disease or valvular disease
• Family history of MI, CAD, sudden death
Physical Exam
May see signs of dyslipidemia (xanthomas, xanthelasma, diminished peripheral pulses, carotid bruits).
TESTS
• ECG
- May show evidence of ischemia or prior myocardial infarction; follow-up testing via angiography is warranted. Other findings are nonspecific and tracings are frequently normal.
- Bundle branch block, Wolff-Parkinson-White syndrome, or intraventricular conduction delay may make the ECG unreliable.
• If normal ECG, exercise stress treadmill testing (ETT) based on probability is indicated.
- ETT with imaging-via echocardiography or perfusion imaging with sestamibi.
- In patients who cannot tolerate exercise, pharmacologic stress testing should be performed
- Women have lower sensitivity and specificity with ETT than do men; exercise echocardiography is indicated
- In Men
 Low probability: ETT without imaging
 Intermediate probability: ETT with imaging
 High probability: ETT prior to angiography
Lab
• Total cholesterol: Frequently elevated
• HDL cholesterol: Frequently reduced
• LDL cholesterol: Frequently elevated
• CRP: Only useful (and offers no better predictive value than standard CHD risk factors) in those with Intermediate to high risk; should be measured at least twice over 2 weeks; is not predictive in low risk patients and in those on a -blocker or statin.
Imaging
• Radionuclide scintigraphy
• Stress echocardiography
• Stress scintigraphy
• Coronary angiography
Diagnostic Procedures/Surgery
• Definitive evaluation requires coronary arteriography for confirmation and delineation of coronary disease, and direction of interventional therapy or surgery. Coronary artery stenting has proven very effective, with restenosis rates (in skilled hands) often 10%, eliminating need for surgery in many cases.
• Surgery in CAD not amenable to angioplasty, and stenting has proven to have a long-term benefit.
Pathological Findings
Atherosclerosis of the coronary arteries
DIFFERENTIAL DIAGNOSIS
• Esophagitis (GERD)
• Esophageal spasm
• Peptic ulcer disease
• Gastritis or nonulcer dyspepsia
• Cholecystitis
• Costochondritis
• Pericarditis
• Aortic dissection
• Pleurisy
• Pulmonary embolus
• Pulmonary hypertension
• Pneumothorax
• Radiculopathy
• Shoulder arthropathy
• Psychological: Anxiety and panic disorders
TREATMENT
PRE-HOSPITAL
• EMS activation if chest discomfort unimproved or worsening 5 minutes after 1 nitroglycerin dose (1)[C]
- EMS to initiate IV, O2, and monitor
- Aspirin administration if ACS suspected and not previously taken or contraindicated
GENERAL MEASURES
• The patient's symptoms should be brought under control medically. If symptoms are unstable, hospitalization is warranted.
• Treatment goal involves reducing myocardial oxygen demand or to increase oxygen supply.
• Noninvasive testing often is indicated as a means of stratifying the patient's risk for an event that might seriously compromise myocardial function.
• Quit smoking.
• Minimize emotional stress.
• Weight reduction in obese patients (2)[C]
Diet
Low-fat, low-cholesterol, low-salt diet
Activity
• As tolerated after consulting physician
• Exercise program after physician's approval; very effective if consistent
SPECIAL THERAPY
Complementary and Alternative Medicine
Relaxation/stress reduction therapy may help reduce anginal aggravations.
MEDICATION (DRUGS)
First Line
• Aspirin: 81-325 mg/d
• -Blockers are effective in reducing heart rate and thereby decreasing oxygen consumption and reducing angina
- Atenolol 25-100 mg/d, metoprolol 25-100 mg b.i.d., or bisoprolol 2.5-10/d
- Adjust doses according to clinical response. Aim to maintain resting heart rate of 50-60 beats per minute.
- Side effects are infrequent but include fatigue, exercise intolerance, erectile dysfunction, and exacerbation of peripheral vascular and obstructive pulmonary disease.
• Nitroglycerin 0.4 mg SL is the most effective therapy for acute anginal episodes
- May repeat 2-3 times over a 10-15 minute period; if no relief, the patient should seek immediate medical attention.
• Long-acting nitrates (mononitrates or transdermal nitrates)
- Should be used with a drug-free interval of 10-14 hours to prevent tolerance
- Tachyphylaxis occurs rapidly.
- Preload reduction and coronary vasodilatation
- Side effects: Headaches and hypotension, tend to clear with continued usage.
- A -blocker or calcium channel blocker should be used in conjunction with the nitrates during the drug-free interval.
- Caution patients not to use in conjunction with oral medicine for erectile dysfunction, such as sildenafil (Viagra).
• Long-acting calcium channel blockers: Verapamil 160-480 mg/d or diltiazem 90-360 mg/d, or nifedipine 30-120 mg/d, or amlodipine 5-20 mg/d. Drug of choice for variant angina. The various agents have their own individual side effects (i.e., verapamil, constipation; nifedipine, peripheral edema).
• HMG CoA reductase inhibitors (e.g., atorvastatin, pravastatin, lovastatin) for hypercholesterolemia: These drugs decrease incidence of symptomatic CAD and reduce both myocardial infarction and death from MI. LDL target levels below 100 mg/dL in diabetes mellitus and 130 mg/dL in low- to moderate-risk patients.
• ACE inhibitors (ramipril 10 mg) in patients with CAD or other vascular disease (3)[B], and particularly those with diabetes or left ventricular (LV) systolic dysfunction (3)[A] have been shown to reduce both cardiovascular death and MI.
• Heparin: Low-molecular-weight heparin should be initiated in patients hospitalized with unstable angina.
• Glycoprotein IIb/IIIa receptor antagonists (Integrilin): Indicated in certain patients hospitalized with unstable angina
• Combination therapy may be used (especially nitrates plus calcium antagonists with or without -blockers).
• Contraindications:
- Sildenafil (Viagra), vardenafil (Levitra), or tadalafil (Cialis) with nitrates should be avoided due to the risk of hypotension and possible death.
• Precautions: Avoid verapamil and diltiazem with compromised ventricular function (LV ejection fraction 40%) especially in conjunction with -blockers.
• Significant possible interactions:
- Combination therapies may impair LV function and precipitate heart failure.
- -Blockers and calcium channel blocker: May combine to produce symptomatic heart block, although either class of drug may act alone in producing this side effect
- Niacin may worsen glucose intolerance.
Second Line
• Current ATP guidelines support the use of lipid-lowering drugs in patients with unfavorable lipid profiles and suspected or documented CAD with or without symptoms (4)[A].
• Consider adding clopidogrel (Plavix) to ASA for severe diffuse CAD. The use of Plavix is indicated after stent placement for at least 9 months to significantly reduce restenosis rates.
SURGERY
Coronary artery bypass graft surgery, angioplasty, stent placement, atherectomy in selected cases
FOLLOW-UP
DISPOSITION
Admission Criteria
Unstable symptoms warrant hospitalization for evaluation.
PROGNOSIS
• Variable; depends on the extent of CAD as well as LV function
• Annual mortality is 3-4% overall
COMPLICATIONS
• Related to myocardial damage occurring during infarction
• Arrhythmia
• Cardiac arrest
• Congestive heart failure
PATIENT MONITORING
• Depends on the frequency and severity of the complaints
• Hospitalization is indicated in patients diagnosed with unstable angina.
REFERENCES
1. Antman EM, Ane DT, Armstrong PW, et al. Guidelines for the management of patients with ST-elevation myocardial infarctionexecutive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2004;110:588-636.
2. Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable anginasummary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2003;107:149-158.
3. Yusuf S, Sleight P, Pogue J, et al. Effects of an angiotensin-converting-enzyme inhibitor ramipril on cardiovascular events in high-risk patients. The HOPE Study Investigators. N Engl J Med. 2000;342:145-153.
4. Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA. 2001;285:2486-2497.