Background
Congestive heart failure (CHF) is a clinical syndrome in which the heart’s inability to adequately receive venous return results in fluid extravasation, most commonly the result of myxomatous mitral valve disease (MMVD) or dilated cardiomyopathy (DCM) in dogs. Other causes of CHF include arrhythmogenic disease and congenital defects.
Management of CHF is continually evolving. Understanding how therapies differ in mechanism, onset, and safety is essential for tailoring treatment to each patient. Detailed information on agent selection and use is available through Plumb’s.
Treatment Options for Congestive Heart Failure
Following are medical options for alleviating clinical signs associated with CHF.
Diuretics increase renal excretion of electrolytes and water.
Loop diuretics (eg, furosemide, torsemide) induce greater diuresis and saliuresis than other diuretics and are foundational for CHF treatment. Furosemide is indicated for acute and chronic CHF treatment in dogs and cats and is available in injectable and oral formulations. Oral torsemide has been used extra-label in dogs and cats and has been conditionally approved for use in dogs.
Spironolactone is used in combination with loop diuretics in dogs and cats with chronic, advanced (ie, stage C or D) CHF.
Thiazides (eg, hydrochlorothiazide) are only used as adjuncts to loop diuretics (ie, sequential diuresis) for advanced cases and are rarely used as a single-agent diuretic for treatment of CHF.
Pimobendan has positive inotropic and vasodilatory effects and is indicated for management in dogs with mild to severe CHF secondary to DCM and preclinical (stage B2) or clinical (stage C or D) MMVD. Along with loop diuretics, pimobendan is a cornerstone of CHF treatment in dogs. The usefulness of pimobendan in cats with CHF appears to be limited to specific scenarios (eg, stage D).1
Angiotensin-converting enzyme (ACE) inhibitors (eg, benazepril, enalapril) are recommended for dogs and cats with chronic CHF and are usually used in combination with a loop diuretic and pimobendan.
Vasodilators (eg, amlodipine, hydralazine) can be considered for dogs with refractory cases.
Arterial thromboembolism (ATE) prevention and treatment are indicated for cats.
Clopidrogrel is an antiplatelet agent used for ATE prevention for cats with CHF.
Factor Xa inhibitors (eg, rivaroxaban) and low molecular weight heparins (eg, dalteparin, enoxaparin) are anticoagulants that can be used for prevention and treatment of ATE.
An Eye on Safety
Loop diuretics and ACE inhibitors are associated with hypotension, electrolyte disturbances, and azotemia. Combinations of these agents are common but can increase these risks.
More information about the safety and efficacy of these drugs is available at Plumbs.com.