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Zorluk: KolayPharmacologic Interventions

A 64-year-old man comes to the primary care clinic for a follow-up appointment. One week ago, he was hospitalized for an acute myocardial infarction and was subsequently found to have a left ventricular ejection fraction of 35% on echocardiography. His medical history is significant for severe bilateral renal artery stenosis, hyperlipidemia, and osteoarthritis. Current medications include aspirin, atorvastatin, and clopidogrel. Blood pressure is 142/88 mm Hg and pulse is 76/min. The patient is euvolemic on physical examination. The physician is planning to optimize the patient's heart failure regimen. Initiation of which of the following medications is contraindicated in this patient?

  1. LisinoprilCevap
  2. B
    Metoprolol succinate
  3. C
    Dapagliflozin
  4. D
    Hydralazine
  5. E
    Furosemide

Cevap

Lisinopril
Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor. In patients with severe bilateral renal artery stenosis, renal blood flow is chronically compromised. The kidneys maintain glomerular filtration rate (GFR) via angiotensin II-mediated vasoconstriction of the efferent arterioles. Administering an ACE inhibitor removes this compensatory mechanism, leading to a precipitous drop in GFR and acute kidney injury. Therefore, ACE inhibitors and angiotensin receptor blockers (ARBs) are absolutely contraindicated in this patient population.

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1
Identify the primary clinical problem and comorbid conditions.
The patient has heart failure with reduced ejection fraction (HFrEF) and severe bilateral renal artery stenosis.
Establishing the patient's complete diagnostic profile is necessary before initiating pharmacologic interventions.
2
Evaluate standard HFrEF therapies against the patient's comorbidities.
Guideline-directed medical therapy for HFrEF includes beta-blockers, ACE inhibitors/ARBs/ARNIs, MRAs, and SGLT2 inhibitors. However, bilateral renal artery stenosis is a critical comorbidity.
Comorbidities can render standard-of-care medications absolutely contraindicated.
3
Identify the absolute contraindication.
ACE inhibitors (like lisinopril) are absolutely contraindicated in patients with bilateral renal artery stenosis.
In bilateral renal artery stenosis, renal perfusion relies heavily on angiotensin II-mediated vasoconstriction of the efferent arteriole; blocking this causes acute kidney injury.

Anahtar Kavram

Angiotensin-converting enzyme (ACE) inhibitors are absolutely contraindicated in patients with bilateral renal artery stenosis because they remove the critical angiotensin II-mediated efferent arteriolar vasoconstriction required to maintain glomerular filtration pressure.
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Pharmacologic Interventions

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