Maybe you should revise your CHF pathways

By Elgin K. Kennedy, MD

Editor

The Assertive Utilization and Quality Report

A recent, large double-blind study has shown that adding the aldosterone-receptor blocker spironolactone (Searle’s Aldactone) to the medication regimen of patients with severe congestive heart failure (CHF) substantially reduces both morbidity and death.1 The accompanying editorial suggests that "the standard of care for the treatment of patients with moderate or severe symptomatic heart failure should be broadened to include spironolactone."2

At present, aldosterone-receptor blockers are used infrequently for heart failure. This is because these drugs are only weak diuretics, and because they have a potential for causing serious hyperkalemia.

This new study, however, shows dramatic benefits from its use. Investigators suspect that the beneficial effects are due to largely unrecognized physiologic actions of the drugs, such as inhibition of myocardial fibrosis, improvement of new vessel formation, and improvement of excitability and contractility of individual myocardial cells.

The authors enrolled 1,663 patients who had severe CHF and who were being treated with an ACE inhibitor, a loop diuretic such as furosemide, and, in most cases, digoxin. The patients were randomized, and half were given po spironolactone 25 mg QD, and the other half were given placebo. After an average treatment time of 24 months, there were only 284 deaths in the spironolactone group while there were 386 deaths in the placebo group — a reduction in the death rate of 30%. Also, the frequency of hospitalization for worsening heart failure was 35% lower in the spironolactone group than in the placebo group. Finally, the spironolactone patients showed significant improvement in their symptoms of heart failure, as assessed with the New York Heart Association functional class methodology.

Overall, patients tolerated the spironolactone well: 8% of the spironolactone patients discontinued treatment because of adverse events as compared to 5% of the placebo patients. Only 14 patients in the spironolactone group and 10 patients in the placebo group developed serious hyperkalemia.

This could be a good time to create, or update, your CHF pathways and practice guidelines. See if they match the two widely accepted standards for the management of CHF:

• Guidelines for the evaluation of management of heart failure: Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Evaluation and Management of Heart Failure). J Am Coll Cardiol 1995; 26(5):1,376-1,398.

• Heart failure: Evaluation and care of patients with left-ventricular systolic dysfunction. U.S. Department of Health and Human Services, Public Health Service, Agency for Health Care Policy and Research; 1994 June. (Clinical practice guideline; no. 11.)

Both guidelines can be found in their entirety at the National Guideline Clearinghouse Web site: www.guideline.gov.

[Editor’s note: The preceding article was first published in the October 1999 issue of The Assertive Utilization and Quality Report — $60 per year (12 issues). For more information, contact Elgin Kennedy, MD, at 204 Second Ave., No. 334, San Mateo, CA 94401. Telephone: (415) 348-3647.]

References

1. Pitt B, Zannad F, Remme WJ, et al. The effect of spironolactone on morbidity and mortality in patients with severe heart failure. N Engl J Med 1999; 341:709-717.

2. Weber KT. Aldosterone and spironolactone in heart failure, Editorial. N Engl J Med 1999; 341:753-755.