A 76-Year-Old Man Comes to the Office for a Follow-Up

A 76-year-old man comes to the office for a follow-up visit after a recent admission for acute decompensated heart failure.  He reports persistent shortness of breath on mild exertion but has no other symptoms.  Medical history includes hypertension, type 2 diabetes mellitus, coronary artery disease, coronary artery bypass grafting 5 years ago, heart failure with reduced ejection fraction (ejection fraction 20%) , benign prostate hyperplasia, and osteoarthritis.  The patient has been hospitalized 4 times over the last year for acute decompensated heart failure.  He had an implantable cardioverter-defibrillator placed 2 years ago.  His medications include low-dose aspirin, metoprolol, lisinopril, simvastatin, insulin glargine, spironolactone, empagliflozin, and furosemide.  Temperature is 36.7 C, blood pressure is 106/72 mm Hg, pulse is 72/min, and respirations are 16/min.  Jugular venous pressure is estimated at 12 cm H₂O.  Lung examination shows bibasilar crackles.  Cardiovascular examination shows regular heart sounds and an audible S3 over the cardiac apex.  There is bilateral lower extremity edema.  Laboratory evaluation shows a serum sodium concentration of 121 mEq/L and serum creatinine of 1.0 mg/dL.  His serum sodium concentration 6 weeks ago was 124 mEq/L and serum creatinine was 0.9 mg/dL.  In addition to adjusting the loop diuretic regimen, which of the following is the most appropriate next step in management of this patient's hyponatremia?

A) Desmopressin
B) Hypertonic saline
C) Losartan
D) Oral salt tablets
E) Water restriction