Clinical twisters: Resolving HF 'revolving door'

May 22, 2006

A 68-year-old man is hospitalized with shortness of breath,fatigue, and 2+ edema-his third hospitalization in 12 months.He has heart failure (HF) (currently New York Heart Associationclass IV, ejection fraction 20%), LVH, and MI history. Heart rhythmis normal; lungs clear; lab tests within normal limits excepthemoglobin510.5 gm/dl, SrCr52.3 mg/dl; BP5160/90, pulse 85,respiratory rate522. Admitting medications: furosemide 80 mg,potassium (K), benazepril 20 mg, aspirin 81 mg, carvedilol (Coreg,GlaxoSmithKline) 6.25 mg twice daily. The resident continues allmedications, increasing furosemide to 80 mg twice daily. He askswhether adding digoxin might reduce future hospitalizations.

A 68-year-old man is hospitalized with shortness of breath, fatigue, and 2+ edema-his third hospitalization in 12 months. He has heart failure (HF) (currently New York Heart Association class IV, ejection fraction 20%), LVH, and MI history. Heart rhythm is normal; lungs clear; lab tests within normal limits except hemoglobin=10.5 gm/dl, SrCr=2.3 mg/dl; BP=160/90, pulse 85, respiratory rate=22. Admitting medications: furosemide 80 mg, potassium (K), benazepril 20 mg, aspirin 81 mg, carvedilol (Coreg, GlaxoSmithKline) 6.25 mg twice daily. The resident continues all medications, increasing furosemide to 80 mg twice daily. He asks whether adding digoxin might reduce future hospitalizations.

Digoxin may be appropriate, although therapies known to reduce mortality aren't yet optimized. Digoxin demonstrated reduced hospitalizations in a large trial but hasn't been shown to reduce mortality. If digoxin is initiated, target=0.5-1.2 ng/ml, rather than 0.8-2 ng/ml (historical target). Given estimated CrCl ~30 ml/ min, use 0.125 mg/day initially.

Consensus guidelines suggest starting and optimizing therapies that reduce mortality (ACE inhibitors; beta-blockers; and, in severe HF, spironolactone) prior to digoxin.

Wait until symptoms stabilize or just before discharge to titrate carvedilol. BP and heart rate will likely tolerate increased dose. Before discharge, increase dose to 12.5 mg twice daily; after two weeks, 25 mg twice daily, based on response.

Spironolactone is indicated in NYHA class III/IV HF with conventional therapy. Target dose=25 mg/ day, based on a large trial suggesting reduced mortality. Major toxicity is hyperkalemia; use cautiously when SrCr >2.5 mg/dl or K >5 mEq/L. Monitor closely. We could initiate outpatient spironolactone after maximizing carvedilol; however, first evaluate K concentrations, likely stopping K supplements prior to starting.

Although controversial, some data suggest torsemide is more predictable than furosemide and may reduce hospitalizations and HF costs in patients like this.
Kevin M. Sowinski, Pharm.D., FCCP, BCPSAssociate Professor-Pharmacy PracticePurdue University, School of Pharmacy and Pharmaceutical Sciences, Indianapolis

Besides HF, this patient has renal insufficiency, poorly controlled hypertension, and anemia. The cause of renal insufficiency is unknown; it could result from poor perfusion or hypertension. Control present symptoms with the furosemide increase, daily weights, dietary restriction counseling, and NSAID avoidance.

After discharge, titrate carvedilol to 25 mg twice daily; increase benazepril as tolerated to 40 mg daily. Monitor serum creatinine and K levels closely. These changes should control BP toward 130/80 target. If renal function declines, consider replacing benazepril with hydralazine/isosorbide (BiDil, NitroMed). Anemia may be secondary to renal disease; increasing hemoglobin may improve symptoms. Initiate darbepoetin therapy to achieve hemoglobin=12 gm/dl.

If symptoms don't improve and admissions continue, initiate digoxin 0.125 mg every other day, titrated to 0.5-0.8 ng/ml. The DIG trial showed lower levels better reduced HF hospital admissions than higher targets.
Ted Walton, Pharm.D., BCPSClinical Pharmacist Specialist-NephrologyGrady Health System Atlanta