A 67-year-old man presents to the emergency room with a 2 day history of progressively worsening fatigue and shortness of breath. His past medical history is significant for previous myocardial infarction, a 30-pack-year smoking history, gastroesophageal reflux disease, and poorly controlled hypertension. The patient’s only home medication is omeprazole. His temperature is 98.6°F (37°C), blood pressure is 140/90 mmHg, pulse is 90/min, respirations are 30/min, and oxygen saturation is 88% on room air. Physical exam is significant for a jugular venous pressure of 15 cm, an S3 heart sound, bibasilar crackles, and 2+ pitting edema to the knees bilaterally. His abdomen is soft and non-tender. His neurological exam is nonfocal and he walks with a steady gait. An arterial blood gas shows the following:

pH: 7.56 (normal 7.35-7.45)
pCO2: 25 mmHg (normal 35-45 mmHg)
HCO3: 29 mEq/L (normal 22-26 mEq/L)
pO2: 62 mmHg (normal 80-100 mmHg)
SaO2: 87% (normal 95-100%)

Which of the following is the most appropriate treatment?
Sacubitril and valsartan
Furosemide
Ivabradine
Metoprolol
Furosemide
This patient with multiple risk factors for heart failure (previous myocardial infarction, smoking history, hypertension), worsening fatigue, shortness of breath, respiratory alkalosis, and signs of fluid overload (S3 heart sound, elevated jugular venous pressure (JVP), bibasilar crackles, peripheral edema) most likely has acute decompensated heart failure (ADHF). The most appropriate initial management for patients in ADHF is a loop diuretic such as furosemide.

Heart failure (HF) is a condition in which the heart does not pump effectively and can be due to either difficulty with relaxation in diastole or contraction in systole or a combination of both. Risk factors for this condition include myocardial infarction, diabetes mellitus, valvular disease, cigarette smoking, hypertension, and obesity. Left-sided HF leads to decreased forward flow into the systemic circulation and increased congestion in the pulmonary circulation which clinically manifests as shortness of breath, pulmonary edema, and crackles on lung exam. Early pulmonary edema leads to a ventilation/perfusion (V/Q) mismatch which causes hypoxia. Hypoxia leads to a compensatory increase in the respiratory rate, which leads to hypocapnia and respiratory alkalosis. The most appropriate initial treatment for patients in ADHF is a loop diuretic such as furosemide, which helps alleviate fluid overload. Other treatments for acute exacerbations may include nitroglycerin (in hypertensive patients) and BIPAP.

Yancy et al. discuss the most recent ACC/AHA guidelines for the management of heart failure. They review current testing and treatment regimens. Acute episodes may be managed with loop diuretics to reduce volume overload and improve symptoms.

Incorrect Answers:
Answer B: Ivabradine inhibits the funny current, an electrical current that leads to spontaneous depolarization in pacemaker cells, leading to decreased heart rate. It reduces the risk of hospitalization in patients with chronic heart failure with reduced ejection fraction (HFrEF). However, it should not be started in ADHF due to lack of mortality benefit and should be held in ADHF patients with severe decompensation due to decreased heart rate leading to decreased cardiac output.

Answer C: Metoprolol is a beta-blocker that reduces mortality when used in patients with chronic HFrEF. However, beta-blockers can worsen decompensated HFrEF due to negative inotropy and should not be started in ADHF.

Answer D: Sacubitril and valsartan is a combination angiotensin receptor-neprilysin inhibitor (ARNI) that improves mortality in patients with chronic HFrEF. ARNIs, angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) should not be started in ADHF due to concern for hypotension and worsening renal function. However, either an ARNI, ACE inhibitor or ARB should be started prior to discharge.

Answer E: Spironolactone is a mineralocorticoid receptor antagonist that reduces mortality in chronic HFrEF. However, high-dose spironolactone does not improve outcomes as first-line therapy in ADHF (Anstrom et al. JAMA Cardiology 2017).

Bullet Summary:
Patients with acute decompensated heart failure present with fatigue, dyspnea, bibasilar crackles, respiratory alkalosis on arterial blood gas, edema, and other signs of fluid overload.