Drugs Used in Congestive Heart Failure

Overview

Diagnosis of CHF at presentation is usually done on chest X-ray. Acutely, IV ACEi and IV lasix will lead to the quickest resolution of symptoms. Once admitted, transition to PO ACEi and PO Lasix, then start a Beta Blocker. Continue morphine, nitrates, and oxygen. If CXR showed HFrEF give dobutamine once admitted. On discharge, give ACEi or substitute with ARB if adverse reaction, loop diuretic, beta-blocker and digoxin (if systolic CHF), nitrates, and spironolactone if patient still has symptoms

• Emergent management of CHF
  • IV ACEi
  • IV loop diuretic (Lasix)
  • Morphine, Nitrates (NG or IV nitropruside), Oxygen
• In-patient management of CHF
  • PO ACEi
  • PO Loop diuretic
  • Beta-Blocker
  • Dobutamine (systolic CHF)
  • Morphine, Nitrates (NG), O2
• Outpatient management of CHF
  • ACEi or ARB
  • Loop diuretic
  • Beta-Blocker
  • Digoxin (systolic CHF)
  • Nitrates (NG/Isosorbide -do not give isosorbide alone)
  • Spironolactone (given if all else fails)
• What reduces mortality in CHF 😊
  • ACEi/ARB
  • Beta-blockers
  • Spironolactone
  • SGLT2-inhibitors
  • ARNIs
• What DOES NOT reduce mortality in CHF 😐
  • Diuretics
  • Positive ionotropes (dobutamine, digoxin)
  • Nitrates/Vasodilators
  • Supportive care: 100% O2, morphine etc.

Strategy

The overall strategy is to reduce pulmonary pressure (PCWP) and hence decrease pulmonary edema

• How can we reduce PCWP?
  • Increase stroke volume
  • Increase LVEF
  • Reduce Systemic Vascular Resistance (Afterload)
  • Increase contractility of the heart
  • Reduce preload volume

ACE Inhibitor

Captopril, Lisinopril.

Reduces preload volume. Adverse effects include cough, hyperkalemia, and hypotension. Contraindicated in pregnancy.

Loop Diuretic

Furosemide.

Reduces preload volume. Adverse effects include hyponatremia, gout and very rarely ototoxicity. Contraindicated in pregnancy.

Nitrates/Vasodilators

Nitroglycerin, isosorbide, nitroprusside, hydralazine.

Promotes an increase in cardiac output by reducing afterload. Adverse effects include hypotension and tachycardia (which may cause ischemia).

• Which nitrate/vasodilator is used in the inpatient setting
  • Nitroglyceride
• Which nitrate/vasodilator is an option in severe emergency cases
  • Nitroprusside
• Which nitrate/vasodilator is longer-acting and is used only in outpatient setting, always in combination
  • Isosorbide
  • If the patient does not have their nitroglycerin (short-acting) at hand they still have vasodilation
• Which nitrate/vasodilator can be used as an add-on in outpatient management
  • Hydralazine

Beta-Blockers

Metoprolol, Carvedilol.

Staple in in-patient and outpatient settings. Not used emergently as it takes time to work. Promotes ventricular filling by reducing the heart rate. Also increases stroke volume by causing vasodilation. Adverse effects include hypotension, hyperkalemia, fatigue, and weakness (Most of these are rare as Beta blockers are generally safe. Hypotension usually occurs in first doses)

• Why is metoprolol preferred in patients with asthma or COPD?
  • It is Beta-1 selective
  ***DO NOT USE CARVEDILOL as it will cause bronchoconstriction

Positive Inotropes

Dobutamine, Digoxin.

Only in SYSTOLIC HF ONLY. Increases cardiac output by increasing intracellular calcium. Adverse effect of digoxin is digoxin (digitalis) toxicity (Hypersalivation, nausea, vomiting, loss of appetite, yellow halos; bradyarrhythmia, PR prolongation → TdP)

• Which positive inotrope is used in the inpatient/emergency setting
  • Dobutamine
• Which positive inotrope is used in the outpatient setting
  • Digoxin
  • Takes a couple of weeks to work
• Digoxin (Digitalis) toxicity syndrome
  • Triggered by hypokalemia (not getting enough potassium) or digoxin overdose
  • Digoxin competes with K+ for the same spot on Na/K ATPase. Less K+ = More digoxin activity
• Why is digitalis toxicity syndrome so rare nowadays?
  • In the past (60s-70s) loop diuretics would cause hypokalemia which would precipitate digitalis toxicity in patients using digoxin
  • Nowadays, ACEis, ARBs, and Beta-Blocker (maybe even spironolactone) will even out potassium levels making digitalis toxicity syndrome rare. Should worry more about hyperkalemia in these patients instead.
• How to treat a patient who presents with digitalis toxicity (brought in unconscious, EKG shows bradyarrhythmia and prolonged PR, PMHx + for digoxin)
  1. Administer Digoxin-immune Fab
  2. Administer atropine for the bradyarrhythmia. Can also give lidocaine
  3. Administer magnesium for prophylaxis against TdP

Angiotensin Receptor Blockers (ARB)

Losartan, Valsartan.

Reduces preload volume. Adverse effects include Hyperkalemia (tend to not see)

Aldosterone Antagonists (Spironolactone)

Spironolactone, Eplerenone.

Reduces preload volume. Can cause severe Hyperkalemia (works directly at the level of aldosterone, really hate to use in the outpatient setting). Second-line treatment when ACEi/ARB + BB + Nitrates aren’t sufficient.

• What are some important precautions to observe when prescribing spironolactone to patients with CHF?
  • Carefully monitor K+ levels
  • Ask patient to monitor symptoms of hyperkalemia (changes in cognition, muscle weakness, fatigue)
  • Keep patient on K+ restricted diet (avoid foods that grow in ground – potato, banana etc.)
  • Keep patient on loop diuretic
  • Discontinue K+ sparing diuretics (Amiloride, Triamterine)

Angiotensin receptor-neprilysin inhibitors (ARNIs)

Sacubitril/Valsartan. Given in HFrEF when first-line drugs fail. Have a better mortality benefit than ACEi or ARBS. Adverse effects include hypotension, cough, dizziness, hyperkalemia

• Dosage
  • Sacubitril/valsartan: Starting dose 49/51 mg BID. Target dose 97/103 mg BID.

SGL2 inhibitors

Dapagliflozin, Empagliflozin. Used in HFrEF with class II or IV symptoms. Can administer along with first-line drugs. Has mortality benefits in patients regardless of the diabetic status. Adverse eEducationffects include dehydration and hypotension