Ischemic Heart Disease

Question 1

What is Ischemic Heart Disease?

Answer 1

•Stable angina, AKA ischemic heart disease (SIHD)
•Angina is chest pain, pressure, tightness
•SIHD is associated with predictable chest pain, usually happens with exertion and relieved within minutes by rest or nitroglycerin
•Unstable angina (UA) is a type of ACS and not relieved with nitroglycerin or rest
•Chest pain caused by vasospasm, its called Prinzmetal’s. This occurs at rest

Question 2

How does chest pain occurs?

Answer 2

•When there is an imbalance between myocardial oxygen demand (workload) and supply (blood flow)
•Atherosclerosis, AKA CAD; causes narrowing of the arteries and reduced blood flow to the heart
^ oxygen demand increases due to the increased HR, contractility or left ventricular wall tension

Question 3

Diagnosis

Answer 3

•Cardiac stress test
^ increases myocardial oxygen demand
•IV medications: adenosine, dipyridamole, dobutamine or regadenoson (Lexiscan)

Question 4

Evaluation of SIHD

Answer 4

•Hx and physical
•CBC, CK-MB, troponins (I or T), aPTT, PT/INR, lipid panel, glucose
•ECG (at rest and during chest pain)
•Cardiac stress test/stress imaging
•Cardiac catheterization/angiography

Question 5

Tx approach

Answer 5

A - Antiplatet and antianginal drugs
B - BP and BBs
C - Cholesterol (statins) and smoking
D - Diet and exercise
E - Exercise and education

Question 6

Antiplatelet Drugs - MOA

Answer 6

• Aspirin irreversibly inhibits COX-1 and 2 which decreases prostaglandin and TXA2
•Clopidogrel is a prodrug that irreversibly inhibits P2Y12 ADP- mediated platelet activation and aggregation

Question 7

Aspirin

Answer 7

•Bayer, Bufferin, Ecotrin, Durlaza(ER)
•75-162 mg daily
•CIs: salicylate allergy; children and teenagers with viral infection due to Reye’s syndrome
•Warnings: bleeding, tinnitus (overdose)
•SEs: Dyspepsia, heartburn, bleeding

• Used indefinitely in SIHD
• Non-enteric coated, chewable aspirin preferred in ACS; if only EC aspirin, it should be chewed (325 mg)
• Durlaza and Yosprala should not be used when rapid onset is needed
  *PPIs may be used to protect gut, however it decreases bone density and increases infection risk

Question 8

Clopidogrel

Answer 8

•Plavix: 75 mg daily
•BW: needs conversion to active metabolite, mainly by CYP450 2C19. Poor metabolizers exhibit more cardiovascular events. CYP2C19 genotype test required
•CIs: serious bleeding
•Warnings: bleeding risk, stop 5 days prior to elective, do not use with omeprazole or esomeprazole

Used when there is a contraindication to aspirin

Question 9

Dual Antiplatelet Therapy (DAPT)

Answer 9

•Combination of aspirin and clopidogrel is reserved for people who had;
^ bare metal stent: for at least a month
^ drug-eluting stent: at least 6 months
^ post-CABG: 12 months

Aspirin should be dosed at 81 mg for DAPT regimens

Question 10

Antiplatelet DDIs

Answer 10

•Most DDIs are due to additive effects with other drugs that can increase bleeding risk (e.g., anticoagulants, NSAIDs, SSRIs, SNRIs, some herbals)

Question 11

Antianginal Treatment - BBs

Answer 11

•1st line in SIHD
•Decreases HR, contractility and left ventricular wall tension

• Titrate to resting HR of 55-60 BPM; avoid abrupt withdrawal
• BBs without ISA are preferred
• Avoid in Prinzmetal’s angina

Question 12

Antianginal Treatment - CCBs

Answer 12

•Preferred for Prinzmetal’s angina
•Non-DHPs decrease HR, DHPs decrease SVR (afterlod)

• Avoid short-acting DHPs (Nifedipine JR)
• DHPs are preferred when CCBs are used in combination with BBs

Question 13

Antianginal Treatment - Nitrates

Answer 13

•Decreases preload (produces vasodilation of veins more than arteries)

• SL tablets, SL powder or TL spray: all patients for fast relief
• Long-acting nitrates: used when BBs are contraindicated or as add-on therapy

Question 14

Antianginal Treatment - Ranolazine

Answer 14

•Ranexa
•CIs: strong CYP3A4 inhibitors or inducers
•Warnings: QT prolongation

NOT for acute tx of chest pain

Question 15

Nitroglycerin Formulations

Answer 15

1) Short-acting Nitrates:
•SL tablet, SL powder, TL spray: 0.4 mg
2) Long-acting Nitrates:
•Ointment 2% (Nitro-Bid)
•Isosorbide mononitrate IR/ER tablet

• CIs: PDE-5 inhibitors
• Warnings: hypotension, headache, tachyphylaxis(decrease effectiveness/tolerance with long acting)
• SEs: headache, flushing, syncope

Question 16

Short-acting Nitrates

Answer 16

•PRN for immediate relief of chest pain
•Store SL tablets in the original amber glass bottle

Question 17

Long-acting Nitrates

Answer 17

•Require 10-12 hr nitrate-free interval to decrease tolerance
^ patch: wear on 12-14 hr, off for 10-12 hr; rotate sites
^ ointment: dosed BID, 6 hrs apart with a 10-12 hr nitrate-free interval
^isosorbide mononitrate: 7 hrs apart BID

• Isosorbide dinitrate in combination with hydralazine is preferred formulation for HFrEF

Question 18

Counseling points - short-acting

Answer 18

• Call 911 asap if chest pain persists after the first dose.
•Continue to take two additional doses at 5 min intervals
•Do not take more than three doses within 15 min

Question 19

Counseling points - SL tablets

Answer 19

•Place the tablet under the tongue, let it dissolve
•Slight burning or tingling is not a sign of how well the med is working
•Keep tightly capped in the amber glass bottle and store at room temperature

Question 20

Counseling points - TL spray

Answer 20

•Do not shake
•Spray onto or under the tongue
•Do not inhale the spray

Question 21

Counseling points - Patch

Answer 21

•Chest is preferred application site

Question 22

Counseling points - Ointment

Answer 22

•Measure the dose with the dose-measuring applicator
•Can stain clothing