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Zorluk: Çok zorPharmacologic Interventions

A 6868-year-old man presents to the cardiology clinic for a routine follow-up. He has a history of nonischemic cardiomyopathy with a left ventricular ejection fraction of 25%25\% diagnosed two years ago, as well as chronic kidney disease. He reports experiencing dyspnea when walking approximately one block and requires two pillows to sleep comfortably at night. His current medications include carvedilol 2525 mg twice daily, dapagliflozin 1010 mg daily, and furosemide 8080 mg twice daily.

Vital signs show a blood pressure of 132/82132/82 mm Hg and a regular heart rate of 6464/min. The estimated jugular venous pressure is 88 cm H 2_2 O. Lungs are clear to auscultation. Cardiac examination reveals a regular rhythm with a normal S1 and S2, and a prominent S3 gallop. There is trace bilateral pedal edema.

Laboratory studies are as follows:

TestResultReference Range
Sodium136136 mEq/L136136-145145 mEq/L
Potassium5.75.7 mEq/L3.53.5-5.05.0 mEq/L
Chloride102102 mEq/L9898-106106 mEq/L
Bicarbonate2222 mEq/L2222-2828 mEq/L
Blood urea nitrogen4242 mg/dL88-2020 mg/dL
Creatinine2.82.8 mg/dL0.70.7-1.31.3 mg/dL

His estimated glomerular filtration rate is 2222 mL/min/1.73m 2^2. The physician wishes to optimize his heart failure regimen to improve symptoms and reduce mortality. Which of the following is the most appropriate next step in the pharmacologic management of this patient?

  1. Initiate isosorbide dinitrate and hydralazineCevap
  2. B
    Initiate sacubitril-valsartan
  3. C
    Initiate spironolactone
  4. D
    Initiate ivabradine
  5. E
    Initiate diltiazem

Cevap

The most appropriate next step is to initiate isosorbide dinitrate and hydralazine.
This patient has symptomatic (NYHA Class III) heart failure with reduced ejection fraction (HFrEF) and is missing a foundational component of guideline-directed medical therapy: afterload/preload reduction with an angiotensin system inhibitor. However, he has advanced chronic kidney disease (eGFR <30< 30 mL/min/1.73m 2^2) and significant baseline hyperkalemia (potassium >5.0> 5.0 mEq/L). These laboratory abnormalities absolutely contraindicate the initiation of ACE inhibitors, angiotensin receptor blockers (ARBs), angiotensin receptor-neprilysin inhibitors (ARNis), and mineralocorticoid receptor antagonists (MRAs). The combination of isosorbide dinitrate (a venodilator reducing preload) and hydralazine (an arterial vasodilator reducing afterload) has been shown to reduce mortality and improve symptoms in HFrEF. Because this combination does not affect renal hemodynamics or potassium excretion, it is the safest and most appropriate mortality-reducing alternative for patients who cannot tolerate standard neurohormonal blockade due to hyperkalemia or renal failure.

Adım Adım Çözüm

1
Analyze the patient's clinical status.
The patient has symptomatic (NYHA Class III) heart failure with reduced ejection fraction (LVEF 25%) despite concurrent use of a beta-blocker, an SGLT2 inhibitor, and a loop diuretic.
Symptomatic HFrEF requires continuous optimization of guideline-directed medical therapy to reduce morbidity and mortality.
2
Identify missing components of guideline-directed medical therapy.
The patient is not currently taking any agent that provides afterload reduction or targets the renin-angiotensin-aldosterone system (RAAS), such as an ACE inhibitor, ARB, ARNi, or MRA.
RAAS inhibition is a foundational pillar for reducing mortality in HFrEF.
3
Evaluate laboratory parameters for contraindications to standard therapies.
The patient has severe hyperkalemia (potassium 5.7 mEq/L) and advanced Stage 4 chronic kidney disease (eGFR 22 mL/min/1.73m²).
These metabolic derangements dictate which classes of medications can be safely initiated.
4
Exclude contraindicated pharmacologic agents.
Sacubitril-valsartan, ACE inhibitors, ARBs, and spironolactone are excluded due to the high risk of exacerbating hyperkalemia and acute kidney injury.
Initiating these drugs in a patient with a baseline potassium > 5.0 mEq/L or eGFR < 30 mL/min/1.73m² poses a severe patient safety risk.
5
Select the appropriate evidence-based alternative.
Isosorbide dinitrate and hydralazine are selected as the optimal combination.
This combination provides mortality-reducing preload and afterload reduction without adversely affecting serum potassium levels or renal hemodynamics.

Anahtar Kavram

In patients with symptomatic heart failure with reduced ejection fraction (HFrEF) who cannot tolerate ACE inhibitors, ARBs, or ARNis due to hyperkalemia or advanced renal insufficiency, the combination of isosorbide dinitrate and hydralazine is the most appropriate pharmacologic intervention to reduce mortality.
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Pharmacologic Interventions

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