Management of stable coronary artery disease (Stable Angina)

byAbdelwahab Ward, BS Pharm, PharmD - last updated
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Assessment (stable chest pain) ― Stable angina should be suspected on the basis of the clinical assessment, and the typicality of chest pain. Classify the symptoms according to their typicality. People with (1) Typical angina presents with all three of the following features: precipitated by physical exertion, constricting discomfort in the front of the chest, in the neck, shoulders, jaw, or arms and relieved by rest or glyceryl trinitrate (GTN) within about 5 minutes. (2) Atypical angina presents with two of the above features. In addition, atypical symptoms include gastrointestinal discomfort, and/or breathlessness and/or nausea.

          Factors that make a diagnosis of stable angina more likely include increasing age, male sex, presence of cardiovascular risk factors and history of established coronary artery disease (for example previous myocardial infarction, coronary revascularization). Factors that make a diagnosis of stable angina less likely include pain that is continuous or prolonged, pain that is unrelated to activity, pain that is brought on by breathing and pain that is associated with dizziness, palpitations, tingling, or difficulty swallowing.

DIAGNOSIS

Confirming a diagnosis of stable angina ― Exclude a diagnosis of stable angina if clinical assessment indicates non-anginal chest pain, unless clinical suspicion is raised based on other aspects of the history and risk factors.

          If the person has typical or atypical anginal pain, refer them to a specialist to confirm, or exclude the diagnosis of stable angina. For people in whom stable angina cannot be excluded on the basis of the clinical assessment alone, organize a resting 12-lead ECG as soon as possible after presentation, depending on local availability. An abnormal ECG makes the diagnosis of coronary artery disease more likely, but does not confirm that the chest pain is stable angina. ECG changes that may indicate ischemia or previous myocardial infarction include pathological Q waves (in particular), left bundle branch block (LBBB) and ST-segment and T-wave abnormalities (for example T-wave flattening or elevation, or T-wave inversion). Do not rule out stable angina on the basis of a normal resting 12-lead ECG. Do not use exercise ECG to diagnose or exclude stable angina for people without known coronary artery disease (CAD). 

How should I manage a person with suspected stable angina who is awaiting diagnostic testing? ― provide the person with sublingual glyceryl di or trinitrate to use for the relief of symptoms while they are waiting for specialist referral. Dinitra 5 mg sublingual, 1 tab. sublingual every 5 min to relief chest pain (if not relief after 3 doses, hospitalized patient to ICU). Nitrolingual 0.4/dose oral spray 1-2 puff under tongue to relief chest pain. 

Instruct the person that if they experience chest pain they should: (1) Stop what they are doing and rest. (2) Use their glyceryl trinitrate spray or tablets as instructed. (3) Take a second dose after 5 minutes if the pain has not eased. (4) Call 123 for an ambulance if the pain has not eased 5 minutes after the second dose, or earlier if the pain is intensifying or the person is unwell. (5) Consider prescribing aspirin (75 mg daily) until the diagnosis is confirmed only if chest pain is considered likely to be stable angina.

MANAGEMENT

Nitroglycerin reduces preload, reduces afterload, dilates collaterals. Beta blockers reduce heart rate, reduces afterload, decreases cardiac contractility and improves survival and decreases MI recurrence following recent MI or LV dysfunction. Contraindication of beta blocker is decompensated congestive heart failure (CHF). Do not combine with calcium channel blockers (verapamil, diltiazem).

Calcium channel blockers reduce afterload, prevents vasoconstriction (no significant effect on vasodilatation). Effective antianginals, but do not decrease mortality. Aspirin (or other antiplatelet agents) to decrease platelet aggregation.

STEPS OF TREATMENT

Step 1. Aspirin 81 mg daily (or clopidogrel 75 mg if aspirin contraindicated), after an episode of acute coronary syndrome or placement of cardiac stents, combination therapy with aspirin plus a clopidogrel (Plavix) is indicated. Duration of dual therapy depends on the bleeding risk and antithrombotic benefit; minimum durations are particularly important to prevent thrombosis within cardiac stents. See, Algorithm for antiplatelet therapy inpatients with stable coronary artery disease. Use sublingual nitroglycerin PRN and before exercise and add beta blocker (start low and go slow) such as metoprolol (Seloken Zoc) 50 to 200 mg orally twice daily or bisoprolol (Concor) 5 to 20 mg orally once daily or carvedilol (Dilatrand) 6.25 to 25 mg orally twice daily

Step 2. Increase beta blocker dose or consider isosorbide monohydrate (once daily, least expensive long acting nitrate) such as Effox or Monomack 20-50 mg orally once daily.

Step 3. Consider adding dihydropyridine calcium channel blocker (e.g. amlodipine), if no systolic dysfunction like amlodipine (Norvasc, Amilo) 5-10 mg orally once daily or felodipine (Plendil) 5-10 mg orally once daily.

  • Other medications like nicorandil (Randil, Adancor) 10 mg twice daily, ideally in the morning and in the evening. A lower starting dose of 5 mg twice daily can be used in people who suffer from headaches. Maintenance dose of nicorandil is 10 to 20 mg twice daily, titrated up to 40 mg twice daily, if required and tolerated. Ranolazine 500-1000 mg orally twice daily is NOT more effective than other anti-anginal medications. Ranolazine has a risk of QT prolongation, multiple drug interactions and high expense. it is Used in combination with other agents above.

Step 4. For refractory angina, consider stress test or angiography again if need > 2 agents. Revascularization may be needed. PCI may improve symptoms but does not reduce mortality in stable coronary disease. CABG is indicated in multi-vessel disease, diabetes mellitus, and > 50% left main coronary artery. See, Algorithm for management of stable coronary artery diseases.  

Statin therapy in patients with coronary artery disease. The American College of Cardiology/American Heart Association (ACC/AHA) transitioned away from low-density lipoprotein (LDL) cholesterol targets to recommend that all patients with stable CAD who are younger than 75 years receive high-intensity statin therapy, which reduces all-cause mortality compared with less intense therapy. Patients 75 years and older and those who cannot tolerate high-intensity statin therapy should receive moderate-intensity statin therapy for secondary prevention.

Table (1). Recommendations of Statins
Medication Indication
High-intensity: atorvastatin (Lipitor, 40 to 80 mg per day) or rosuvastatin (Crestor, 20 to 40 mg per day) Patients younger than 75 years
Moderate-intensity: atorvastatin (10 to 20 mg per day), rosuvastatin (5 to 10 mg per day), simvastatin (Zocor, 20 to 40 mg per day) Patients 75 years and older, or in whom high-intensity statins are not tolerated

Lifestyle modification ― Engaging in 30 to 60 minutes of moderate-intensity aerobic activity (e.g., brisk walking) five to seven days per week and increasing daily lifestyle activities have been shown to reduce cardiovascular mortality and smoking cessation.

REFERENCES

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