Angina

Question 1

Pathophysiology of Angina

Answer 1

Clinical syndrome characterized by chest and/or arm discomfort

Caused by an imbalance between myocardial oxygen supply & demand (ischemia)

Associated with coronary artery disease

Pain is reproducible with physical exertion or emotional stress

Relieved by nitroglycerine

Question 2

Goals of Drug Therapy for Angina

Answer 2

Elimination of anginal pain
BP less than 130/85 & pulse greater than 70 bpm
Reduce the risk of myocardial infarction (MI) & death

Treatment is aimed at:

• increasing myocardial oxygen supply
• Reducing myocardial demand
• Minimizing or removing the occlusion

Question 3

Treatment for Angina

Answer 3

Lifestyle changes 
Surgical intervention 
Pharmacological management
- Aspirin
- Nitrates
- BBs
- CCBs
- ACEIs
- Statins

Question 4

Coronary Vasodilators: Pharmacodynamics & Examples

Answer 4

Agents that serve to increase myocardial oxygen supply

Nitrates (nitroglycerin, isosorbide)
- Prototype: nitroglycerine (NTG)

Calcium Channel Blockers

Question 5

Nitrates Action

Answer 5

Low dose NTG dilate the veins, decreasing venous return to heart
- Decreases preload

Higher doses dilate arterial vessels
- Decrease vascular resistance (afterload)

Some dilation of coronary arteries occur
- Atherosclerotic vessels do not dilate

Question 6

NTG Precautions & Contraindications

Answer 6

Contraindicated in hypersensitivity or idiosyncratic responses

Transdermal patches: allergy to adhesive may limit use

Pregnancy category C

Question 7

BBs for Angina

Answer 7

BBs decrease the force of myocardial contractility & decrease HR & conduction velocity

BBs decrease systemic vascular resistance & BP (afterload)

Decreased myocardial oxygen demand= decreased anginal pain

Question 8

CCBs for Angina

Answer 8

CCBs cause arterial smooth muscle relaxation, which leads to peripheral vasodilation and decreased afterload

CCBs may cause coronary vasodilation
- Atherosclerotic vessels do not dilate

Question 9

ACEIs for Angina

Answer 9

Act on the RAAS system

Decreased peripheral vascular resistance
- Decreased afterload

Indirectly reduce the secretion of aldosterone

• Decreased sodium and water retention
• Reducing extracellular fluid volume and preload

Question 10

Aspirin and Statins for Angina

Answer 10

Aspirin:
- Decreases platelet aggregation to prevent cycle of vasoconstriction and platelet build up

Statins:

• Preventive
• Reduce in low-density lipoprotein cholesterol levels, which plays a significant role in decreasing the formation of atherosclerotic plaque

Question 11

Rational Drug Selection

Answer 11

Grading of Angina by the New York Heart Association and Canadian Cardiovascular Society

All patients with angina should be on aspirin 81-325 mg/day
- If patient cannot tolerate aspirin, then clopidogrel (Plavix) 75 mg may be substituted

NTG for exertional angina
- sublingual tablet (0.3-0.4 mg) or translingual spray is used for immediate symptom relief

Question 12

Drugs for Stable Angina

Answer 12

ACEI
- Recommended for all symptomatic patients with chronic stable angina to prevent MI or death & to reduce symptoms

ARBs
- For all patients who are intolerant to ACEIs

BBs
- Recommended as initial therapy by all the guidelines for all patients

CCBs
- Initial drugs of choice for coronary artery vasospasm-associated angina

Question 13

Long-Acting Nitrates: Use and Route

Answer 13

Oral or transdermal (patch)
Used for patients intolerant to BBs
Isosorbide dinitrate (Isordil) given 2-3 times/day 
- With a 10-12 hour nitrate-free interval to prevent nitrate tolerance 
- Timing of the nitrate-free interval should coincide with the time of fewest episodes of angina

Question 14

Non-Nitrate: Ranolizine

Answer 14

Oral, ER capsule for chronic angina with continuous chest pain symptoms
- Decreases use of NTG and frequency of events

Unknown MOA

Not for emergency use

QT interval prolongation issues at high doses

Question 15

Multi-Drug Therapy for Angina

Answer 15

Combinations of BBs and CCBs have been shown to be more effective than individual drugs used alone; can add ranolizine too

Combinations of long-acting nitrate & BB are safe, effective, & low in cost

Combination of long-acting nitrates & CCBs is rarely used because of high risk for hypotension & additive adverse reaction profiles

Question 16

Patient Variables & Treatment for Angina

Answer 16

Older adults
- ACEI and BBs if patient has CHF– CCBs will make CHF worse

Women

• No gender-based difference in therapy
• Women undertreated

Question 17

Angina: Cost of Treatment & Initial Assessment

Answer 17

Cost of Treatment:
- Nitrates cheapest; BBs mid-range for cost (older drugs cheaper); CCBs & ACEIs the most expensive (generics less expensive)

Initial Assessment:
- ECG; fasting lipid levels; chest x-ray; CBC; tests for diabetes; thyroid function; and renal function

Question 18

Angina: Monitoring

Answer 18

Angina Episodes
- Presence, characteristics, and timing

Evaluation every 4-6 months during the first year of therapy

Questions to ask:

• Has the patient’s level of physical activity decreased since last visit?
• How well is the patient tolerating therapy?
• How successful has the patient been in modifying risk factors & improving knowledge about ischemic heart disease?
• Has the patient developed any new comorbid illnesses, or has the severity or treatment of known comorbid illnesses worsened the patient’s angina?

Question 19

Angina: Patient Education

Answer 19

Taking the drug exactly as prescribed

• Eccentric dosing of some long-acting nitrates
• Use of sublingual NTG

If anginal symptoms occur at night, the nitrate free time is during the day

Storage of NTG
- Avoiding heat and moisture
NTG expiration date