New drugs, research will change the way you manage CHF patients
New treatments include beta blockers, Aldactone, and ACE inhibitors
When a patient with congestive heart failure (CHF) comes to your ED with a severe exacerbation, new medications can have a dramatic effect on their quality of life, reports Victoria L. Mugica, RN, BSN, clinical program coordinator for the center for heart failure management at the University of Chicago Hospital.
"These patients become symptomatic very easily, so they often come to the ED," says Mugica. "Approximately 250,000 patients die as a direct or indirect consequence of CHF every year."1
The risk of death is 5% to 10% annually in patients with mild symptoms and increases to as high as 30% to 40% annually in patients with advanced disease, notes Mugica.2
A 1993 study showed that 80% of men and 65% of woman die within six years after a diagnosis of CHF,3 but that’s no longer the case, says June Howland-Gradman, RN, clinical director of cardiac services at the University of Chicago Hospital.
"That number is changing as we’re coming out with better medications," Howland-Gradman says. (See related stories: home management, p. 146; tips for CHF management, p. 147; CHF therapies, p. 148; and CHF clinics, p. 149.)
Here is an update on the most recent developments in CHF management:
• Beta blockers.
In the past, beta blockers were never a part of CHF treatment, stresses Mugica. "They were actually contraindicated, because the negative inotropic effect [decreased contractility] was felt to worsen the CHF symptoms," she says.
Researchers have shown this drug can be given safely. "They believe this drug has a protective effect by blocking the effect of the increased levels of epinephrine and norepinephrine seen with chronic heart failure, thus lowering myocardial oxygen consumption, and slowing progression of the disease," Mugica explains.4
Many CHF patients have had heart attacks in the past, so they might be on beta blockers, notes David Wilcox, MD, FACEP, medical director for ConnectiCare, an HMO in Farmington, CT, and associate professor of emergency medicine at University of Massachusetts Medical School in Worcester.
It has become standard of care to place myocardial infarction (MI) patients on beta blockers, unless they have specific contraindications, notes Wilcox. "MI is a risk factor for developing CHF," he explains. "Thus, post-MI patients who develop CHF may have been on beta blockers."
Whether the patient stays on beta blockers or not depends on the severity of CHF weighted against the potential beneficial effect post-MI, Wilcox notes.
"In the old days, we used to be cautious about using beta blockers with CHF patients, because they suppress the heart to some extent," he explains. "We still need to be cautious. But studies over the last few years have shown good evidence that it prevents future heart attacks. So now even chronic CHF patients are on beta blockers."
Still, if a patient comes in with severe CHF, they shouldn’t be put on beta blockers because they depress the heart. "But if they’ve had previous problems and have already been on beta blockers, it could be indicated," Wilcox notes. "However, you must act cautiously and be aware of possible side effects once you get the patient through the episode."
Don’t give additional doses until the immediate problem is under control, he adds. If you were to overuse beta blockers in a patient with acute CHF, it could worsen the episode. The balance is like walking a tightrope, says Wilcox.
"You need to give enough medicine to support the heart. But if you overwork the heart, it can actually worsen the episode," he explains. "Beta blockers are good over the long term, but you would not use them up front with an acute exacerbation."
Beta blocker approved for CHF
• Carvedilol.
Carvedilol, manufactured by SmithKline Beecham in Philadelphia, is the only beta blocker currently FDA-approved for congestive heart failure. (To obtain more information on Carvedill, see Resource on p. 145.) "It has been shown to reduce progression of heart failure by about 47%, so it’s become part of our standard therapy for patients in Class II or III heart failure," says Mugica.5
Carvedilol may be somewhat safer than other beta blockers, but it is still only used on mild to moderate CHF patients, notes Wilcox. "Cavedilol is also far more expensive than some other beta blockers. So it may not be used in milder CHF cases where the margin of safety is wider."
The drug has alpha and nonselective beta-blockade thought to be important in decreasing afterload and counteracting the increased sympathetic activity, Mugica notes. "This is now considered standard treatment for patients with mild to moderate CHF already on triple therapy."
Carvedilol is only initiated on patients who have been stable on standard triple therapy for at least six weeks, stresses Mugica. "If the patient has recently been started on Carvedilol, they are at higher risk for CHF exacerbation and developing volume overload," she warns. "So patients need to be very careful about noticing symptoms that develop after initiation of the medication, such as weight increases."
If patients come in with an exacerbation, ask them if they are new to Carvedilol or have just changed the dose, Mugica advises.
• Aldactone.
"This is the newest medication being added to therapy in the outpatient setting," reports," says Mugica. "It prevents the progression of the disease so well that the RALES (Randomized Aldactone Evaluation Study) trial was stopped early because of the dramatic effects."6,7
In addition a diuretic effect, CHF patients also get increased potassium intake from Aldactone. "So patients can be taken off potassium supplements, which will likely increase compliance since the supplements have an unpleasant taste, can be difficult to swallow, and/or cause stomach upset," says Mugica. "There are fewer side effects, and it’s much easier for patients to tolerate."
Aldactone is a long-term therapy used to slow the progression of the disease, notes Mugica. "The benefits of the RALES study indicated that treatment with Aldactone was associated with a 27% reduction in mortality; a 36% decrease in hospitalization; and a 22% reduction in the combined risk of death or hospitalization."
Hyperkalemia may be a side effect. "You may want to draw labs and look for peaked T-waves on the EKG," says Howland-Gradman. "You may hook a patient up to an EKG and see lots of PVCs [pulmonary ventricular contractions] for those patients who are on diuretics but aren’t taking potassium supplements."
Aldactone is used specifically for patients who have a problem with losing potassium, Wilcox explains. "Very often, CHF patients are on diuretics long term, such as HCTZ [hydrochlorothiazide] or Lasix [furosamide], and those can cause your body to lose potassium," he explains.
Aldactone is a diuretic that helps you retain the potassium, but older patients with renal insufficiency may retain too much potassium. "Kidneys are important in maintaining the balance of potassium in your body," Wilcox notes. "In people with renal failure, there is a potential for retaining too much potassium, so they shouldn’t be on Aldactone."
Symptoms for too much or too little potassium are similar, and may include muscle cramping, Wilcox notes. "The symptoms are usually vague, such as fatigue or not feeling quite right," he says.
Don’t forget to look at potassium levels, Wilcox advises. "If a CHF patient is on the mild to moderate spectrum, you will be looking at electrolytes and urinalysis, but you should also be checking the patient’s potassium levels," he says.
• ACE inhibitors.
In the last few years, more CHF patients have been put on ACE (angiotensin converting enzymes) inhibitors, because studies have shown they reduce morbidity and mortality, notes Wilcox. "These are antihypertensives and only recently started being used for CHF patients."
Studies have shown that the CHF patients have a tendency to have better outcomes if they’re taking ACE inhibitors, says Wilcox.
"If patients are not on them already, we can potentially start them in the ED," he says. "If a patient is exacerbated while in the ED, that may be one of the medications we may add, along with time-honored medications like morphine or nitroglycerin."
References
1. American Heart Association. 1998 Heart and Stroke Statistical Update. Dallas: American Heart Association; 1997.
2. Massie MD, Shah NB. Evolving trends in the epidemiologic factors in heart failure: Rationale for preventive strategies and comprehensive disease management. Am Heart J 1997; 133:703-712.
3. Ho KKL, Pinsky JL, Kannel WB, et al. The epidemiology of heart failure: the Framingham study. J Am Coll of Cardiol 1993; 22(suppl):6A-13A.
4. Krum H. Beta blockers in heart failure: The new wave of clinical trials. Drugs 1999; 58:203-210.
5. Packer M, Bristow MR, Cohn JN, et al. The U.S. Carvedilol heart failure study group: The effect on Carvedilol on morbidity and mortality in patients with chronic heart failure. N Engl J Med 1996; 334:1,349-1,355.
6. Effectiveness of spironolactone added to an ACE inhibitor and a loop diuretic for severe chronic congestive heart failure (the randomized aldactone evaluation study). Am J Cardiol 1996; 78:902-907.
7. Pitt B. Presentation of the results of the RALES trial. Presented at the American Heart Association Scientific Sessions. Dallas; November 1998.
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