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Cardiovascular Pharmacotherapy & Anticoagulation

Manage heart failure, hypertension, and anticoagulation with warfarin/DOACs; recognize drug interactions, monitoring parameters, and reversal strategies.

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Cardiovascular Pharmacotherapy & Anticoagulation

Master cardiovascular pharmacotherapy and anticoagulation with free flashcards and evidence-based clinical strategies. This lesson covers heart failure management, anticoagulation therapy selection, and antiarrhythmic drug optimizationβ€”essential concepts for NAPLEX success and clinical practice.

Welcome πŸ«€

Cardiovascular pharmacotherapy represents one of the most high-yield domains on the NAPLEX and in clinical practice. With heart disease remaining the leading cause of mortality worldwide, your ability to optimize antihypertensives, anticoagulants, antiarrhythmics, and heart failure medications will directly impact patient outcomes. This lesson synthesizes guideline-directed medical therapy (GDMT) with practical clinical pearls to help you confidently answer exam questions and manage real patients.

πŸ’‘ Why This Matters: Cardiovascular questions consistently comprise 15-20% of NAPLEX content. Beyond the exam, these medications have narrow therapeutic windows, significant drug interactions, and require individualized dosing strategies.

Core Concepts

Heart Failure Pharmacotherapy πŸ«€

Heart failure with reduced ejection fraction (HFrEF) requires a foundational approach using the "Fantastic Four" medication classes:

<table> <tr> <th>Medication Class</th> <th>Examples</th> <th>Mechanism</th> <th>Mortality Benefit</th> </tr> <tr> <td><strong>ACE Inhibitors / ARNi</strong></td> <td>Lisinopril, Sacubitril-Valsartan</td> <td>Block RAAS, reduce afterload</td> <td>βœ… 20-25% reduction</td> </tr> <tr> <td><strong>Beta Blockers</strong></td> <td>Carvedilol, Metoprolol succinate, Bisoprolol</td> <td>Reduce heart rate, myocardial Oβ‚‚ demand</td> <td>βœ… 30-35% reduction</td> </tr> <tr> <td><strong>Mineralocorticoid Receptor Antagonists</strong></td> <td>Spironolactone, Eplerenone</td> <td>Block aldosterone effects</td> <td>βœ… 30% reduction</td> </tr> <tr> <td><strong>SGLT2 Inhibitors</strong></td> <td>Dapagliflozin, Empagliflozin</td> <td>Improve cardiac metabolism, reduce volume</td> <td>βœ… 25-30% reduction</td> </tr> </table>

🧠 Mnemonic: "BEDS" for HFrEF

  • Beta blockers (carvedilol, metoprolol succinate, bisoprolol)
  • Enalapril/ACEi or Entresto (ARNi)
  • Dapagliflozin/SGLT2i
  • Spironolactone/MRA

Key Titration Principles:

  • Start low, go slow for beta blockers (may worsen HF initially)
  • ACEi/ARB/ARNi: Monitor K⁺ and SCr (expect 30% SCr increase is acceptable)
  • ARNi requires 36-hour ACEi washout to prevent angioedema
  • SGLT2i: Check for genital mycotic infections, volume depletion

πŸ’‘ Clinical Pearl: Sacubitril-valsartan (Entresto) is superior to enalapril in reducing cardiovascular death and HF hospitalization (PARADIGM-HF trial). Consider switching stable patients from ACEi to ARNi.

Anticoagulation Therapy Selection 🩸

Choosing the right anticoagulant depends on indication, renal function, drug interactions, and patient factors:

<table> <tr> <th>Indication</th> <th>First-Line Options</th> <th>Key Considerations</th> </tr> <tr> <td><strong>Atrial Fibrillation</strong></td> <td>DOACs > Warfarin</td> <td>Use CHAβ‚‚DSβ‚‚-VASc for risk, HAS-BLED for bleeding</td> </tr> <tr> <td><strong>VTE Treatment</strong></td> <td>DOACs or LMWHβ†’Warfarin</td> <td>Rivaroxaban/Apixaban don't require bridge</td> </tr> <tr> <td><strong>Mechanical Heart Valve</strong></td> <td>Warfarin ONLY</td> <td>DOACs contraindicated</td> </tr> <tr> <td><strong>STEMI/ACS</strong></td> <td>Dual antiplatelet therapy</td> <td>Aspirin + P2Y₁₂ inhibitor Γ— 12 months</td> </tr> </table>

Direct Oral Anticoagulants (DOACs) - The "ABCR" Family:

<pre> β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β” β”‚ DOAC COMPARISON CHART β”‚ β”œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€ β”‚ β”‚ β”‚ Factor Xa Inhibitors: β”‚ β”‚ β”œβ”€ Apixaban (Eliquis) - Twice daily, ↓ GI bleedβ”‚ β”‚ β”œβ”€ Rivaroxaban (Xarelto) - Once daily, with foodβ”‚ β”‚ └─ Edoxaban (Savaysa) - Once daily β”‚ β”‚ β”‚ β”‚ Direct Thrombin Inhibitor: β”‚ β”‚ └─ Dabigatran (Pradaxa) - Twice daily, ↑ GI bleedβ”‚ β”‚ β”‚ β”‚ All DOACs: β”‚ β”‚ βœ“ No routine monitoring β”‚ β”‚ βœ“ Fewer drug-food interactions β”‚ β”‚ βœ“ Rapid onset/offset (6-12 hours) β”‚ β”‚ βœ— More expensive than warfarin β”‚ β”‚ ⚠️ Avoid if CrCl <15-30 (drug-dependent) β”‚ β”‚ β”‚ β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜ </pre>

Warfarin Management Essentials:

  • Target INR: 2-3 (most indications), 2.5-3.5 (mechanical valves)
  • Major interactions: Antibiotics, azoles, amiodarone, NSAIDs
  • Reversal: Vitamin K (slow), 4-factor PCC (fast)
  • Genetic testing (CYP2C9, VKORC1) may guide initial dosing

🧠 Mnemonic: "REVERT" for DOAC Reversal

  • Rixaraban β†’ Andexanet alfa
  • Edoxaban β†’ Andexanet alfa
  • Vitamin K antagonist (warfarin) β†’ Vitamin K, PCC
  • Eliquis (apixaban) β†’ Andexanet alfa
  • Re-dose if needed
  • Thrombin inhibitor (dabigatran) β†’ Idarucizumab

Antiarrhythmic Drugs ⚑

Vaughan Williams Classification remains the framework for understanding antiarrhythmics:

<table> <tr> <th>Class</th> <th>Mechanism</th> <th>Drugs</th> <th>Primary Use</th> <th>Key Toxicity</th> </tr> <tr> <td><strong>IA</strong></td> <td>Na⁺ block (moderate)</td> <td>Quinidine, Procainamide, Disopyramide</td> <td>Rarely used</td> <td>QT prolongation, torsades</td> </tr> <tr> <td><strong>IB</strong></td> <td>Na⁺ block (weak)</td> <td>Lidocaine, Mexiletine</td> <td>Ventricular arrhythmias</td> <td>CNS effects, seizures</td> </tr> <tr> <td><strong>IC</strong></td> <td>Na⁺ block (strong)</td> <td>Flecainide, Propafenone</td> <td>AF (no structural disease)</td> <td>Pro-arrhythmic, avoid in CAD</td> </tr> <tr> <td><strong>II</strong></td> <td>Beta blockade</td> <td>Metoprolol, Esmolol</td> <td>Rate control, SVT</td> <td>Bradycardia, hypotension</td> </tr> <tr> <td><strong>III</strong></td> <td>K⁺ block (prolong repolarization)</td> <td>Amiodarone, Dofetilide, Sotalol</td> <td>AF rhythm control</td> <td>QT prolongation, thyroid (amio)</td> </tr> <tr> <td><strong>IV</strong></td> <td>Ca²⁺ block</td> <td>Diltiazem, Verapamil</td> <td>Rate control, SVT</td> <td>Bradycardia, constipation</td> </tr> </table>

🧠 Mnemonic: "FAST-PASS" for Antiarrhythmic Classes

  • Fast Na⁺ blockers (IA, IB, IC)
  • Amiodarone (III)
  • Sotalol (II + III)
  • Thymol (amiodarone thyroid toxicity)
  • Propranolol (II)
  • ATP-sensitive (Class I avoid post-MI)
  • SVT treated with IV adenosine first
  • Structural heart disease β†’ avoid IC drugs

Amiodarone Special Considerations:

  • Most effective antiarrhythmic but significant toxicity profile
  • Loading: 400-600 mg daily Γ— weeks, maintenance 200 mg daily
  • Monitor: TFTs every 6 months, PFTs baseline/annual, LFTs, ophthalmology
  • Drug interactions: Warfarin (↓ dose 30-50%), digoxin (↓ dose 50%)
  • Contains iodine: Can cause hyper- OR hypothyroidism

πŸ’‘ Did You Know? Amiodarone has a half-life of 40-60 days due to extensive tissue distribution. This means adverse effects can persist for months after discontinuation!

Antiplatelet Therapy πŸ’Š

Dual Antiplatelet Therapy (DAPT) is standard post-ACS and after PCI:

<pre> DAPT DECISION TREE

     πŸš‘ ACS or PCI with Stent
              β”‚
              ↓
     β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
     β”‚ Aspirin 81 mg dailyβ”‚ (Indefinite)
     β”‚        +           β”‚
     β”‚   P2Y₁₂ inhibitor  β”‚
     β””β”€β”€β”€β”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜
              β”‚
  β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
  β”‚                       β”‚

β”Œβ”€β”€β”΄β”€β”€β”€β”€β”€β”€β” β”Œβ”€β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”€β” β”‚ Standardβ”‚ β”‚ High Risk β”‚ β”‚ Risk β”‚ β”‚ Bleeding β”‚ β””β”€β”€β”¬β”€β”€β”€β”€β”€β”€β”˜ β””β”€β”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”€β”˜ β”‚ β”‚ ↓ ↓ Ticagrelor 90 mg BID Clopidogrel 75 mg or Prasugrel 10 mg (less potent, (more potent) fewer bleeds) β”‚ β”‚ β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜ β”‚ ↓ Duration: 12 months (minimum 6 months for BMS, 12 months for DES/ACS) </pre>

P2Y₁₂ Inhibitor Comparison:

<table> <tr> <th>Drug</th> <th>Prodrug?</th> <th>Onset</th> <th>Advantages</th> <th>Disadvantages</th> </tr> <tr> <td><strong>Clopidogrel</strong></td> <td>Yes</td> <td>2-6 hours</td> <td>Generic, lower bleeding risk</td> <td>CYP2C19 polymorphism (poor metabolizers), slower onset</td> </tr> <tr> <td><strong>Prasugrel</strong></td> <td>Yes</td> <td>30 min</td> <td>Faster onset, more potent</td> <td>↑ bleeding, avoid if age >75, weight <60 kg, prior stroke</td> </tr> <tr> <td><strong>Ticagrelor</strong></td> <td>No</td> <td>30 min</td> <td>Reversible, faster offset, no genetic variability</td> <td>BID dosing, dyspnea side effect, aspirin must be ≀100 mg</td> </tr> </table>

⚠️ Critical Point: Ticagrelor is LESS effective when combined with aspirin >100 mg daily. Always use aspirin 81 mg with ticagrelor!

Hypertension Management 🩺

Guideline-directed approach (ACC/AHA 2017):

First-Line Agents:

  1. Thiazide diuretics (HCTZ, chlorthalidone)
  2. ACE inhibitors (lisinopril, enalapril)
  3. ARBs (losartan, valsartan)
  4. Calcium channel blockers (amlodipine, diltiazem)

Compelling Indications for Specific Agents:

<table> <tr> <th>Condition</th> <th>Preferred Agent</th> <th>Rationale</th> </tr> <tr> <td>Heart Failure (HFrEF)</td> <td>ACEi/ARB + Beta blocker</td> <td>Mortality benefit proven</td> </tr> <tr> <td>Post-MI</td> <td>Beta blocker + ACEi</td> <td>Reduce remodeling, recurrent MI</td> </tr> <tr> <td>Diabetes + Proteinuria</td> <td>ACEi or ARB</td> <td>Renal protection</td> </tr> <tr> <td>Chronic Kidney Disease</td> <td>ACEi or ARB</td> <td>Slow progression</td> </tr> <tr> <td>Recurrent Stroke</td> <td>Thiazide + ACEi</td> <td>Secondary prevention</td> </tr> <tr> <td>Benign Prostatic Hyperplasia</td> <td>Alpha blocker</td> <td>Dual benefit</td> </tr> </table>

🧠 Mnemonic: "ABCD" for HTN Drug Classes

  • ACE inhibitors / ARBs (–prils, –sartans)
  • Beta blockers (–olols)
  • Calcium channel blockers (–dipines, diltiazem, verapamil)
  • Diuretics (thiazides, loops, K-sparing)

African American Patients: First-line should be CCB or thiazide (ACEi/ARB less effective as monotherapy)

Lipid Management 🧬

Statin Intensity Matters More Than Target LDL:

<table> <tr> <th>Intensity</th> <th>LDL Reduction</th> <th>Drugs (mg/day)</th> </tr> <tr> <td><strong>High</strong></td> <td>β‰₯50%</td> <td>Atorvastatin 40-80, Rosuvastatin 20-40</td> </tr> <tr> <td><strong>Moderate</strong></td> <td>30-50%</td> <td>Atorvastatin 10-20, Rosuvastatin 5-10, Simvastatin 20-40</td> </tr> <tr> <td><strong>Low</strong></td> <td><30%</td> <td>Simvastatin 10, Pravastatin 10-20</td> </tr> </table>

When to Add Non-Statin Therapy:

  • Ezetimibe: Add if LDL still elevated on max-tolerated statin (↓LDL additional 20%)
  • PCSK9 inhibitors (alirocumab, evolocumab): Very high-risk patients with LDL β‰₯70 on statin + ezetimibe
  • Bempedoic acid: Alternative if statin-intolerant

πŸ’‘ Clinical Pearl: Avoid simvastatin 80 mg due to increased myopathy risk. Simvastatin is also limited to 10-20 mg when combined with amiodarone or diltiazem due to CYP3A4 interactions.

Examples

Example 1: HFrEF Optimization

Clinical Scenario: JM is a 62-year-old male with HFrEF (EF 25%), currently on lisinopril 20 mg daily. Labs: K⁺ 4.2, SCr 1.1, BP 128/76, HR 84 bpm. What medication changes should be made?

Solution: This patient needs optimization to quadruple therapy:

<table> <tr> <th>Step</th> <th>Action</th> <th>Rationale</th> </tr> <tr> <td>1</td> <td>Add beta blocker (carvedilol 3.125 mg BID)</td> <td>Start low, titrate to target or max tolerated dose</td> </tr> <tr> <td>2</td> <td>Add SGLT2 inhibitor (dapagliflozin 10 mg daily)</td> <td>Mortality benefit regardless of diabetes status</td> </tr> <tr> <td>3</td> <td>Add MRA (spironolactone 12.5-25 mg daily)</td> <td>Monitor K⁺ weekly initially (target <5.5)</td> </tr> <tr> <td>4</td> <td>Consider switching ACEi to ARNi after stabilization</td> <td>Superior outcomes but requires 36-hour washout</td> </tr> </table>

Key Monitoring:

  • Beta blocker: May worsen symptoms initially (reassure patient this is expected)
  • K⁺ with MRA + ACEi: Check in 1 week, then monthly
  • SCr: 30% increase acceptable with RAAS inhibitors
  • BP: Ensure systolic >90 mmHg before each titration

Example 2: Anticoagulation Selection in AF

Clinical Scenario: RS is a 68-year-old female with newly diagnosed atrial fibrillation. PMH: hypertension, type 2 diabetes. CHAβ‚‚DSβ‚‚-VASc score = 4. CrCl 55 mL/min. Should she receive anticoagulation? Which agent?

Solution:

Step 1: Calculate CHAβ‚‚DSβ‚‚-VASc

  • Congestive HF: 0
  • Hypertension: +1
  • Age β‰₯75: 0 (age 65-74 = +1)
  • Diabetes: +1
  • Stroke/TIA history: 0
  • Vascular disease: 0
  • Age 65-74: +1
  • Sex category (female): +1
  • Total: 4 (High risk, definitely anticoagulate)

Step 2: Choose Agent

DOACs preferred over warfarin. All DOACs acceptable with CrCl >30:

<table> <tr> <th>DOAC</th> <th>Dose for AF</th> <th>Renal Consideration</th> </tr> <tr> <td>Apixaban</td> <td>5 mg BID (2.5 mg BID if 2/3: age β‰₯80, weight ≀60 kg, SCr β‰₯1.5)</td> <td>Best option if CrCl 15-30</td> </tr> <tr> <td>Rivaroxaban</td> <td>20 mg daily with dinner (15 mg if CrCl 15-50)</td> <td>MUST take with food</td> </tr> <tr> <td>Edoxaban</td> <td>60 mg daily (30 mg if CrCl 15-50 or weight ≀60 kg)</td> <td>Avoid if CrCl >95 (less effective)</td> </tr> <tr> <td>Dabigatran</td> <td>150 mg BID (75 mg BID if CrCl 15-30)</td> <td>Avoid if CrCl <30, highest GI bleed risk</td> </tr> </table>

Recommendation: Apixaban 5 mg BID (patient doesn't meet dose reduction criteria). Counsel on adherence importance with BID dosing.

Example 3: Amiodarone Drug Interactions

Clinical Scenario: KT is hospitalized with new-onset rapid AF. Started on amiodarone loading (400 mg BID). Home medications: warfarin 5 mg daily (INR goal 2-3 for prior DVT), digoxin 0.25 mg daily. What adjustments are needed?

Solution:

Amiodarone has critical interactions via CYP3A4 and P-glycoprotein inhibition:

<pre> AMIODARONE INTERACTION CASCADE

Amiodarone Started
       |
       ↓
β”Œβ”€β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”€β”
β”‚             β”‚
↓             ↓

Warfarin Digoxin (CYP2C9) (P-gp) β”‚ β”‚ ↓ ↓ ↑ INR ↑ Levels Toxicity Toxicity β”‚ β”‚ ↓ ↓ Bleeding Brady/ AV block </pre>

Required Actions:

  1. Warfarin: Reduce dose by 30-50% immediately

    • New dose: 2.5-3.5 mg daily
    • Check INR in 3-5 days (interaction takes several days)
    • Expect INR to rise significantly
  2. Digoxin: Reduce dose by 50%

    • New dose: 0.125 mg daily
    • Check digoxin level in 5-7 days
    • Monitor for bradycardia (both drugs slow AV node)
  3. Additional Monitoring:

    • Baseline TFTs, LFTs, PFTs (amiodarone toxicity screening)
    • EKG for QTc interval
    • Potassium and magnesium (replete if low to prevent torsades)

⚠️ Critical Point: These interactions persist for WEEKS after stopping amiodarone due to its long half-life!

Example 4: Post-STEMI Medication Reconciliation

Clinical Scenario: BN is a 54-year-old male being discharged after anterior STEMI with drug-eluting stent placement. What medications should be prescribed?

Solution:

Mandatory Post-STEMI Therapy ("ABC-DAPT"):

<table> <tr> <th>Medication</th> <th>Drug/Dose</th> <th>Duration</th> <th>Purpose</th> </tr> <tr> <td><strong>Aspirin</strong></td> <td>81 mg daily</td> <td>Indefinite</td> <td>Antiplatelet foundation</td> </tr> <tr> <td><strong>P2Y₁₂ inhibitor</strong></td> <td>Ticagrelor 90 mg BID (preferred) OR Clopidogrel 75 mg daily</td> <td>12 months minimum</td> <td>Prevent stent thrombosis</td> </tr> <tr> <td><strong>Beta blocker</strong></td> <td>Metoprolol succinate 25-200 mg daily OR Carvedilol 6.25-25 mg BID</td> <td>Indefinite</td> <td>↓ mortality, remodeling</td> </tr> <tr> <td><strong>ACE inhibitor</strong></td> <td>Lisinopril 5-40 mg daily</td> <td>Indefinite</td> <td>↓ remodeling, mortality</td> </tr> <tr> <td><strong>High-intensity statin</strong></td> <td>Atorvastatin 80 mg daily</td> <td>Indefinite</td> <td>Plaque stabilization</td> </tr> </table>

Additional Considerations:

  • Check echocardiogram: If EF <40%, add aldosterone antagonist (eplerenone 25 mg daily)
  • Nitroglycerin SL 0.4 mg PRN for chest pain
  • Cardiac rehabilitation referral
  • Smoking cessation if applicable

🧠 Discharge Mnemonic: "ABCDE" Post-MI

  • Aspirin + Antiplatelet (DAPT)
  • Beta blocker
  • Cholesterol management (high-intensity statin)
  • Diet and diabetes management
  • Enalapril/ACE inhibitor

Common Mistakes ⚠️

1. Incorrect DOAC Dosing in Renal Impairment

Mistake: Using standard DOAC doses when CrCl is reduced Impact: Accumulation and bleeding risk Solution: Always calculate CrCl and adjust:

  • Apixaban: Reduce to 2.5 mg BID if meets 2 of 3 criteria (age β‰₯80, weight ≀60 kg, SCr β‰₯1.5)
  • Rivaroxaban: 15 mg daily if CrCl 15-50
  • Edoxaban: 30 mg daily if CrCl 15-50
  • Dabigatran: 75 mg BID if CrCl 15-30

2. Starting Beta Blocker During Acute Decompensated HF

Mistake: Initiating or continuing beta blocker when patient has volume overload Impact: Worsens acute symptoms, hypotension Solution: Stabilize with diuretics FIRST, then restart beta blocker at low dose once euvolemic

3. Combining ACE Inhibitor + ARB

Mistake: Using dual RAAS blockade thinking it's more effective Impact: Hyperkalemia, hypotension, acute kidney injury (ONTARGET trial showed harm) Solution: Use ACEi OR ARB, not both. If inadequate, add different class or switch to ARNi

4. Forgetting Amiodarone-Warfarin Interaction

Mistake: Starting amiodarone without adjusting warfarin Impact: INR rises dangerously, major bleeding risk Solution: Reduce warfarin by 30-50% immediately and monitor INR closely (every 3-5 days initially)

5. Using Aspirin >100 mg with Ticagrelor

Mistake: Prescribing standard aspirin 325 mg with ticagrelor post-ACS Impact: REDUCED efficacy of ticagrelor (PLATO trial) Solution: Always use aspirin 81 mg (maximum 100 mg) when combined with ticagrelor

6. Inappropriate Class IC Antiarrhythmic Use

Mistake: Using flecainide or propafenone in patients with structural heart disease or CAD Impact: Increased mortality (CAST trial) Solution: Screen for structural disease (echo) before Class IC drugs. If present, use amiodarone or dofetilide instead

7. Missing Sacubitril-Valsartan Washout Period

Mistake: Switching directly from ACEi to ARNi Impact: Severe angioedema risk Solution: MANDATORY 36-hour washout between last ACEi dose and first ARNi dose

8. Statin Intolerance Mismanagement

Mistake: Discontinuing all statins after muscle complaints without rechallenge Impact: Loss of cardiovascular benefit Solution: Rule out other causes, try different statin, lower dose, alternate-day dosing, or add ezetimibe/bempedoic acid

Key Takeaways 🎯

βœ… HFrEF requires quadruple therapy: Beta blocker + ACEi/ARNi + MRA + SGLT2i (all have mortality benefit)

βœ… DOACs preferred over warfarin for AF and VTE (except mechanical valves, which REQUIRE warfarin)

βœ… Amiodarone has numerous interactions: Reduce warfarin 30-50%, reduce digoxin 50%, and monitor thyroid/liver/lungs

βœ… Post-ACS requires DAPT: Aspirin 81 mg + P2Y₁₂ inhibitor for 12 months minimum

βœ… Ticagrelor + aspirin rule: Never exceed aspirin 100 mg daily with ticagrelor (reduced efficacy)

βœ… Class IC drugs contraindicated in structural heart disease (flecainide/propafenone increase mortality)

βœ… ARNi requires 36-hour ACEi washout to prevent angioedema

βœ… High-intensity statins for ASCVD: Atorvastatin 40-80 mg or rosuvastatin 20-40 mg

βœ… Calculate CHAβ‚‚DSβ‚‚-VASc for all AF patients: Score β‰₯2 (male) or β‰₯3 (female) = anticoagulate

βœ… Beta blockers in HF: "Start low, go slow" - may worsen symptoms initially but provide long-term benefit

πŸ“š Further Study

  1. ACC/AHA Heart Failure Guidelines: https://www.acc.org/guidelines/
  2. 2023 AF Anticoagulation Update: https://www.ahajournals.org/journal/circ
  3. NAPLEX Cardiovascular Review (NABP): https://nabp.pharmacy/programs/naplex/

<div style="border: 2px solid #4fd1c5; border-radius: 8px; padding: 16px; margin: 16px 0; background: rgba(79, 209, 197, 0.1);"> <h4>πŸ“‹ Quick Reference Card - Cardiovascular Pharmacotherapy</h4>

<table> <tr> <th>Category</th> <th>Key Points</th> </tr> <tr> <td><strong>HFrEF "BEDS"</strong></td> <td><strong>B</strong>eta blocker, <strong>E</strong>nalapril/ARNi, <strong>D</strong>apagliflozin, <strong>S</strong>pironolactone</td> </tr> <tr> <td><strong>DOACs "ABCR"</strong></td> <td><strong>A</strong>pixaban, <strong>B</strong>ase dose on renal function, <strong>C</strong>ontraindicated in mechanical valves, <strong>R</strong>ivaroxaban with food</td> </tr> <tr> <td><strong>DAPT Duration</strong></td> <td>12 months post-ACS or DES; Aspirin 81 mg + P2Y₁₂ inhibitor</td> </tr> <tr> <td><strong>Amiodarone Interactions</strong></td> <td>↓ Warfarin 30-50%, ↓ Digoxin 50%, monitor TFTs/PFTs/LFTs</td> </tr> <tr> <td><strong>Class IC Contraindication</strong></td> <td>NO structural heart disease or CAD (use amiodarone instead)</td> </tr> <tr> <td><strong>ARNi Switch</strong></td> <td>36-hour washout from ACEi required (angioedema risk)</td> </tr> <tr> <td><strong>High-Intensity Statins</strong></td> <td>Atorvastatin 40-80 mg or Rosuvastatin 20-40 mg</td> </tr> <tr> <td><strong>CHAβ‚‚DSβ‚‚-VASc</strong></td> <td>CHF, HTN, Ageβ‰₯75(Γ—2), DM, Stroke(Γ—2), Vascular, Age 65-74, Sex(F); β‰₯2β™‚/β‰₯3♀ = anticoagulate</td> </tr> <tr> <td><strong>Ticagrelor Rule</strong></td> <td>Aspirin MUST be ≀100 mg (81 mg preferred)</td> </tr> <tr> <td><strong>RAAS Monitoring</strong></td> <td>K⁺ and SCr in 1 week; 30% SCr increase acceptable</td> </tr> </table> </div>