NAPLEX Heart Failure Practice Questions with Answers

Mastering the management of Heart Failure (HF) is essential for success on the NAPLEX, as it integrates complex pharmacotherapy, monitoring parameters, and clinical guidelines. This guide provides comprehensive NAPLEX Heart Failure practice questions designed to test your knowledge of drug classes, dosing, and patient counseling.

Preparing for the board exam requires a deep understanding of the NAPLEX Prep curriculum, particularly how to manage patients with reduced ejection fraction (HFrEF). You should also review related topics such as NAPLEX Hypertension Medication Practice Questions and NAPLEX Cardiovascular Pharmacology Practice Questions to build a solid foundation in hemodynamics.

Concept Explanation

Heart failure is a clinical syndrome characterized by the heart's inability to pump sufficient blood to meet the body's metabolic demands, often resulting from structural or functional cardiac disorders. In the context of the NAPLEX, the focus is primarily on Heart Failure with Reduced Ejection Fraction (HFrEF), defined as an ejection fraction (EF) of $\leq 40\%$. Management follows the American College of Cardiology (ACC) and American Heart Association (AHA) guidelines, which emphasize the use of Guideline-Directed Medical Therapy (GDMT) to reduce mortality and hospitalizations.

The four pillars of GDMT for HFrEF include:

• Angiotensin Receptor-Neprilysin Inhibitor (ARNI): Preferred over ACE inhibitors or ARBs to reduce morbidity and mortality.
• Beta-Blockers: Specifically carvedilol, metoprolol succinate, or bisoprolol.
• Mineralocorticoid Receptor Antagonists (MRA): Such as spironolactone or eplerenone.
• SGLT2 Inhibitors: Such as dapagliflozin or empagliflozin, regardless of diabetes status.

Clinicians must also understand the NYHA Functional Classification (I-IV) and ACC/AHA Stages (A-D). For instance, Stage C represents structural heart disease with prior or current symptoms of HF. Pharmacists play a vital role in monitoring serum potassium, renal function (CrCl), and blood pressure while ensuring patients avoid medications that can exacerbate HF, such as non-steroidal anti-inflammatory drugs (NSAIDs) and certain calcium channel blockers like verapamil or diltiazem.

Solved Examples

1. Example: Switching from ACEI to ARNI

   A patient is currently taking lisinopril 20 mg daily and the physician wants to start Entresto (sacubitril/valsartan). What is the necessary washout period?

   1. Identify the drug interaction: Combining an ACE inhibitor with a neprilysin inhibitor increases the risk of angioedema.
   2. Determine the protocol: A 36-hour washout period is required when switching from an ACE inhibitor to Entresto.
   3. Note: No washout period is required when switching from an ARB to Entresto.
   4. Answer: 36 hours.
2. Example: Calculating Target Doses

   A patient is being titrated on Coreg (carvedilol) for HFrEF. The patient weighs 75 kg. What is the target dose?

   1. Recall carvedilol dosing: For patients $\leq 85 \text{ kg}$, the target dose is 25 mg BID.
   2. Recall carvedilol dosing: For patients $> 85 \text{ kg}$, the target dose is 50 mg BID.
   3. Apply weight: 75 kg is less than 85 kg.
   4. Answer: 25 mg BID.
3. Example: Loop Diuretic Equivalency

   A patient is switching from 40 mg of oral furosemide to oral torsemide. What is the equivalent dose?

   1. Recall the ratio: Furosemide 40 mg : Torsemide 20 mg : Bumetanide 1 mg : Ethacrynic acid 50 mg.
   2. Calculate: $\frac{40 \text{ mg Furosemide}}{20 \text{ mg Torsemide}}$.
   3. Answer: 20 mg of torsemide.

Practice Questions

1. A 64-year-old male with HFrEF (EF 30%) and a history of angioedema from enalapril is being evaluated for new therapy. Which medication is most appropriate to initiate for mortality benefit?
2. A patient with HF is prescribed spironolactone. Which laboratory value would be a contraindication to starting this medication?
3. Which of the following beta-blockers is NOT evidence-based for reducing mortality in HFrEF?

4. A patient is hospitalized for an acute HF exacerbation and is found to have a serum digoxin level of 1.8 ng/mL. The patient is experiencing visual disturbances (yellow-green halos). What is the appropriate management?
5. Which SGLT2 inhibitor is FDA-approved for the treatment of HFrEF in patients without type 2 diabetes?
6. A patient with NYHA Class III heart failure and persistent symptoms despite GDMT has a heart rate of 78 bpm in sinus rhythm. Which medication could be added to specifically reduce the heart rate?
7. Which of the following medications can cause or worsen heart failure by promoting fluid retention?
8. A patient is being discharged on BiDil. What are the two active components of this medication?
9. What is the therapeutic range for digoxin in the treatment of heart failure?
10. A patient with HFrEF is currently taking Lisinopril 10 mg daily. The provider wants to switch to Entresto 49/51 mg BID. What advice should the pharmacist give regarding the transition?

Answers & Explanations

1. Answer: Valsartan or Hydralazine/Isosorbide Dinitrate (BiDil). Explanation: Since the patient has a history of angioedema with an ACE inhibitor, ARBs should be used with extreme caution, though some guidelines allow them. However, BiDil is a specific alternative for patients who cannot tolerate ACEIs/ARBs, particularly in African American patients. Entresto is contraindicated in patients with a history of angioedema.
2. Answer: Potassium $> 5.0 \text{ mEq/L}$ or CrCl $\leq 30 \text{ mL/min}$. Explanation: MRAs like spironolactone can cause life-threatening hyperkalemia. Initiation is not recommended if potassium is high or renal function is significantly impaired.
3. Answer: Metoprolol tartrate (Lopressor). Explanation: Only metoprolol succinate (Toprol XL), carvedilol (Coreg), and bisoprolol (Zebeta) have proven mortality benefits in HFrEF clinical trials.
4. Answer: Discontinue digoxin and consider Digifab. Explanation: The therapeutic range for digoxin in HF is 0.5–0.9 ng/mL. A level of 1.8 ng/mL combined with visual disturbances indicates toxicity.
5. Answer: Dapagliflozin (Farxiga) or Empagliflozin (Jardiance). Explanation: Both have been shown to reduce the risk of cardiovascular death and HF hospitalization in patients with HFrEF, regardless of diabetes status.
6. Answer: Ivabradine (Corlanor). Explanation: Ivabradine is indicated for patients with stable HFrEF (EF $\leq 35\%$) in sinus rhythm with a resting heart rate $\geq 70 \text{ bpm}$ who are on maximally tolerated beta-blockers.
7. Answer: Pioglitazone (Actos) or NSAIDs (like Ibuprofen). Explanation: Thiazolidinediones cause sodium and water retention. NSAIDs also cause fluid retention and can decrease the effectiveness of diuretics.
8. Answer: Hydralazine and Isosorbide Dinitrate. Explanation: BiDil is a fixed-dose combination used to reduce mortality in African American patients with NYHA Class III-IV HFrEF.
9. Answer: $0.5–0.9 \text{ ng/mL}$. Explanation: Higher levels (up to 2.0 ng/mL) may be targeted for atrial fibrillation, but for heart failure, lower levels are safer and effective.
10. Answer: Stop Lisinopril and wait 36 hours before starting Entresto. Explanation: This washout period is mandatory to prevent angioedema caused by the dual inhibition of ACE and neprilysin.

1. Which of the following is a potential side effect of Entresto (sacubitril/valsartan)?

• AHypokalemia
• BHypotension
• CHypernatremia
• DTachycardia

Frequently Asked Questions

What is the difference between HFrEF and HFpEF?

HFrEF (Heart Failure with Reduced Ejection Fraction) occurs when the ejection fraction is 40% or less, indicating a pumping problem, while HFpEF (Preserved Ejection Fraction) occurs when the EF is 50% or more, indicating a filling problem due to a stiff heart muscle.

Why are SGLT2 inhibitors used in heart failure?

SGLT2 inhibitors like dapagliflozin and empagliflozin reduce the risk of cardiovascular death and hospitalization by promoting osmotic diuresis and natriuresis, which decreases preload and afterload on the heart.

Can a patient take both an ACE inhibitor and an ARB for heart failure?

No, combining an ACE inhibitor and an ARB is generally avoided because it increases the risk of adverse effects like hyperkalemia and renal impairment without providing significant additional mortality benefit.

What should patients be told about monitoring their weight?

Patients with heart failure should weigh themselves daily every morning after voiding and notify their provider if they gain more than 2-3 pounds in a single day or 5 pounds in a week.

Which calcium channel blockers are safe in HFrEF?

Only long-acting dihydropyridine calcium channel blockers like amlodipine or felodipine are considered safe if needed for blood pressure control; non-dihydropyridines like verapamil and diltiazem are contraindicated due to their negative inotropic effects.