Drugs for Heart Failure

Drugs for Heart Failure

• Heart failure is a chronic, progressive, and incurable condition where the heart struggles to pump enough blood to supply the body with sufficient oxygen.
• Basic mechanisms include systolic dysfunction, diastolic dysfunction, and compensatory mechanisms.
• Systolic dysfunction (HFrEF): Impaired ventricular contraction, with increased ventricular volumes, and ejection fraction below 40%.
  • Causes include coronary artery disease, myocardial infarction, and dilated cardiomyopathy.
  • Clinical features include fatigue, dyspnea (shortness of breath), and reduced exercise tolerance.
• Diastolic dysfunction (HFpEF): Impaired ventricular relaxation and filling, with increased filling pressures.
  • Ejection fraction is 50% or greater
  • Causes include hypertension, hypertrophic cardiomyopathy, and aging.
  • Clinical features include dyspnea, orthopnea (difficulty breathing while lying down), and fluid retention.
• Compensatory mechanisms involve the heart trying to maintain cardiac output:
  • Increased sympathetic nervous system activity
  • Renin-angiotensin-aldosterone system (RAAS) activation
  • Atrial natriuretic peptides

Congestive Heart Failure

• Signs and symptoms often associated with congestive heart failure include raised jugular venous pressure, pulmonary edema, cardiomegaly, pleural effusions, hepatomegaly, ascites, and peripheral pitting edema.

NYHA Functional Classification

• This system classifies heart failure severity by functional limitations. The classes range from no limitations (Class 1) to severe limitations with symptoms even at rest (Class 4).

AHA/ACC Stages

• Stages of heart failure risk:
  • Stage A: At-risk for heart failure
  • Stage B: Pre-heart failure
  • Stage C: Symptomatic heart failure
  • Stage D: Advanced heart failure

Treatment of Heart Failure-Beta Blockers

• Beta-blockers (e.g., Metoprolol, Carvedilol, Bisoprolol) are used to manage heart failure.
  • They block beta-adrenergic receptors, lowering heart rate and myocardial contractility
  • This can lower myocardial oxygen demand and reduce mortality.
  • Common indications include heart failure, hypertension, and post-myocardial infarction.
  • Potential adverse effects: bradycardia, hypotension, fatigue, depression.
  • Drug interactions include calcium channel blockers, and antiarrhythmics.

Treatment of Heart Failure-ACE Inhibitors

• ACE inhibitors (e.g., Enalapril, Lisinopril) are indicated to manage heart failure by suppressing angiotensin II formation.
  • Reduced preload and afterload, decreased ventricular remodeling.
  • Indications include heart failure and hypertension.
  • Potential adverse effects include: cough, hyperkalemia, hypotension, and renal dysfunction.
  • NSAIDs can reduce their anti-hypertensive effects and increase the risk of renal dysfunction.

Treatment of Heart Failure-Angiotensin II Receptor Blockers (ARBs)

• Angiotensin II Receptor Blockers (ARBs) (e.g., Losartan, Valsartan) help by blocking angiotensin II receptors.
  • Prevent vasoconstriction, aldosterone release.
  • Indications include heart failure and hypertension.
  • Potential adverse effects include hyperkalemia, hypotension, and renal dysfunction.

Treatment of Heart Failure-Angiotensin Receptor-Neprilysin Inhibitors (ARNIs)

• ARNIs (e.g., Sacubitril/Valsartan) are used to improve symptoms and reduce hospitalizations in heart failure.
  • By inhibiting neprilysin, this increases natriuretic peptides and reduces cardiac workload
  • Indications include heart failure with reduced ejection fraction (HFrEF)
  • Potential adverse effects may include angioedema, hyperkalemia, hypotension, and renal dysfunction.

Treatment of Heart Failure-Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitors

• SGLT2 Inhibitors (e.g., Dapagliflozin, Empagliflozin) are used to treat heart failure.
  • Inhibit sodium-glucose transporter 2 (SGLT2) in the kidneys, enhancing glucose excretion.
  • This reduces preload and afterload, improves glycemic control, and reduces body weight.
  • Indications include heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), type 2 diabetes with cardiovascular disease.
  • Adverse effects include genital mycotic infections, urinary tract infections and potential hypoglycemia/dehydration.

Treatment of Heart Failure- Mineralocorticoid Receptor Antagonists (MRAs)

• Mineralocorticoid receptor antagonists (MRAs) (e.g., Spironolactone, Eplerenone) are used to manage heart failure. - Block mineralocorticoid receptors (in the kidney, heart and vasculature) to reduce sodium/water retention, decreasing blood pressure and cardiac workload. - Reduce mortality and hospitalizations and improve symptoms. - Indications include heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). - Adverse effects include hyperkalemia, gynecomastia (spironolactone), and renal dysfunction. - Interactions with ACEis, ARBs, potassium supplements, NSAIDs.

Treatment of Heart Failure-Hydralazine/Isosorbide Dinitrate (BiDil)

• Hydralazine and isosorbide dinitrate (BiDil) are used as an adjunct therapy in African American patients with heart failure.
  • Hydralazine lowers afterload by dilating arterioles.
  • Isosorbide dinitrate reduces preload by dilating veins.
  • Improves symptoms, enhances quality of life, and reduces hospitalizations. Considered in patients unable to tolerate ACEi or ARBs.

Treatment of Heart Failure - Diuretics

• Diuretics (e.g., furosemide, hydrochlorothiazide, spironolactone, eplerenone) are often used to manage heart failure.
  • Increase sodium and water excretion by the kidneys, leading to reduced blood volume.
  • Results in decreased preload and afterload, reducing edema and pulmonary congestion
  • Aids in managing fluid overload and symptoms of congestion.
  • May include adverse effects such as electrolyte imbalances, dehydration, hypotension, and renal dysfunction, Drug interactions common, including potassium-sparing diuretics, NSAIDs, and antihypertensive drugs.

Treatment of Heart Failure - Digoxin

• Digoxin is a medication used to treat heart failure.
  • Enhances cardiac contractility and reduces heart rate, decreasing workload.
  • Indications include heart failure and atrial fibrillation.
  • Potential adverse effects include digoxin toxicity, various arrhythmias, visual disturbances, and electrolyte imbalances (hypokalemia).
  • Drug interactions include diuretics, amiodarone, verapamil and quinidine.
  • Contraindicated in ventricular fibrillation, hypersensitivity or severe renal impairment.

Combined Therapy

• Combining different drugs may offer synergistic effects and improved outcomes compared to individual medications alone. Possible examples include ACE inhibitors with beta-blockers, and others (e.g. MRA, diuretics) depending on the clinical need

Explore the various drug treatments available for heart failure, a chronic condition affecting the heart's ability to pump blood. This quiz covers the basic mechanisms of heart failure, including systolic and diastolic dysfunction, as well as compensatory mechanisms and clinical features associated with the disease.