Use of conivaptan for the treatment of symptomatic hyponatremia in a patient with acute decompensated heart failure

Purpose. The successful use of conivaptan for the treatment of symptomatic hypervolemic hyponatremia in a patient with acute decompensated heart failure is reported. Summary. A 67-year-old woman with severe ischemic dilated cardiomyopathy was admitted to the hospital due to a heart failure exacerbation. She was initially managed with furosemide and milrinone, but her condition continued to worsen. By hospital day 10, her serum sodium concentration had decreased to 114 meq/L. A 96-hour trial of conivaptan was initiated, and the patient's serum sodium concentration increased to 125 meq/L, blood urea nitrogen level decreased from 34 to 15 g/dL, serum creatinine concentration decreased from 1.1 to 0.9 g/dL, and fluid balance was -9800 mL. After completion of the 96-hour trial of conivaptan, the patient quickly decompensated. Conivaptan was restarted three days later; again, the patient's sodium level quickly increased, and aquaresis occurred. By hospital day 24, the patient was stable enough to undergo a cardiac catheterization, and a stent was placed. On day 26, the patient died while being prepared for an upgrade to a biventricular implantable cardioverter defibrillator. Multiple trials have evaluated conivaptan for the treatment of heart failure. Conivaptan improves hyponatremia and hemodynamic parameters acutely and increases urine output but has failed to show improvement in heart failure symptoms in the published literature. No adverse cardiac effects resulted from the use of conivaptan in this patient. Conclusion. Treatment with i.v. conivaptan in a patient with symptomatic hyponatremia and acute decompensated heart failure resulted in marked diuresis and improvement of hyponatremia.