Heart Failure: A Dynamic Approach to Classification and Management
Although accreditation for this CE/CME activity has expired, and the posttest is no longer available, you can still read the full article.
Expires April 30, 2019
Heart failure is a complex syndrome with a spectrum of signs and symptoms that range from asymptomatic to terminal. This variability of presentation, paired with the irreversibility of the process, make it both difficult and critical to identify this syndrome early to prevent progression. Here is an overview of the classification and common presentations of heart failure, as well as a guide to diagnostic modalities and treatment options.
Pharmacotherapy
Diuretics have not been found to have benefit for reducing early mortality but are the most common agents used for symptomatic relief of sodium and water retention.26 In fact, few patients with signs and symptoms of fluid retention can be managed without a diuretic.9 Caution must be observed, however, because excessive diuresis can lead to electrolyte imbalance and neurohormonal activation.
Treating mild fluid retention with a thiazide diuretic (hydrochlorothiazide, metolazone, or chlorthalidone) is often sufficient (see Table 2 for dosing and other information on these and other drugs for treating HF).9 Thiazide diuretics are dependent on the glomerular filtration rate and are ineffective when it falls below 30-40 mL/min. Adverse reactions to diuretics include hypokalemia, dehydration (intravascular volume depletion) with prerenal azotemia, skin rash, neutropenia, thrombocytopenia, hyperglycemia, hyperuricemia, and hepatic dysfunction.
In cases of moderate or severe HF, or failure of thiazide diuretics to relieve mild symptoms, an oral loop diuretic (furosemide, bumetanide, or torsemide; see Table 2 for dosing) can be used if kidney function is preserved.9 These agents are best administered in two or more divided doses. Major adverse reactions are similar to those of thiazide diuretics, plus ototoxicity. Special caution must be used when a loop diuretic is co-administered with digitalis because the combination can cause significant hypokalemia.9
A potassium-sparing diuretic (triamterene or amiloride; see Table 2) can be used in combination with thiazide and loop diuretics.9 The location of their action is at the distal tubule, but diuretic potency is mild. Potassium-sparing agents can minimize hypokalemia induced by other diuretics. Adverse effects include hyperkalemia, kidney dysfunction, and gastrointestinal symptoms.
The aldosterone-receptor antagonists spironolactone and eplerenone are specific inhibitors of aldosterone, an effect that has been shown to improve clinical outcomes.9 Aldosterone-receptor antagonists are indicated for patients with NYHA class II-IV HF who have LVEF ≤ 35% or those with a history of acute MI, LVEF < 40%, and symptoms of HF.27 In these patients, a reduction in mortality and relative risk has been demonstrated with the use of aldosterone-receptor antagonists, unrelated to their role in diuresis. The adverse effect profile of spironolactone includes gynecomastia.
Continue to: Inhibitors of the RAAS
