Diuretic drugs are medications that help the kidneys remove excess fluid from the body, helping to lower blood pressure and decrease edema and fluid overload. They do this by stimulating the kidneys to excrete sodium (salt). Sodium molecules associate with water, so when they're eliminated by the kidneys, they take water with them. This reduces the amount of excess fluid in the blood and in the body. Heart failure often gives rise to fluid overload, and people with heart failure are commonly treated with diuretic drugs. Recent evidence suggests, however, that long-term, aggressive use of diuretics in patients with heart failure may not be prudent.
As heart failure progresses, a number of symptoms related to fluid overload can appear. Excess fluid can enter the tiny air sacs in the lungs and reduce the amount of oxygen that can enter the blood, causing shortness of breath (dyspnea). Fluid can accumulate in the lungs when a patient lies down at night and make nighttime breathing and sleeping difficult (orthopnea), or even cause the patient to wake up suddenly gasping for air (paroxysmal nocturnal dyspnea). Fluid overload can also occur in the lower limbs and/or abdomen. One million people are hospitalized each year in the United States for heart failure, 90 percent of them for symptoms related to fluid overload.
Diuretics and Heart Failure
A number of recent studies have raised concerns about the use of diuretics in heart failure patients experiencing symptoms of fluid overload.
One study of 522 critically ill patients with acute kidney failure from four academic medical centers affiliated with the University of California showed that diuretic use in these patients was associated with an increased risk of death.
Another study of 1,354 patients with advanced heart failure referred to a single university medical center showed that there was an association between chronic (long-term) use of loop diuretics (a powerful type of diuretic drug often used for patients with heart failure) and increased risk of death. The study also showed that this increased risk of death was related to the dose of the loop diuretic. Patients taking higher doses of loop diuretics had a higher risk of death than did patients taking lower doses.
A third study of heart failure patients 65 years of age and older compared a group of 651 patients who were taking diuretics with a group of 651 patients who were not taking diuretics. The results demonstrated that chronic diuretic use was associated with a significantly increased risk of hospitalization and death in a wide spectrum of older adults with heart failure.
The relationship between diuretic use and risk of death in heart failure patients who have a severe form of kidney disease known as renal insufficiency was studied by researchers in the Acute Decompensated Heart Failure National Registry (ADHERE), the world's largest heart failure registry. ADHERE contains a collection of data on heart failure patients going back to 2001, and it holds data on 105,000 patients with decompensated heart failure (a condition in which the heart is unable to maintain adequate blood circulation).
In this analysis, patients were divided into two groups: those with and without renal insufficiency. Renal insufficiency was measured using the serum creatinine test -- patients with creatinine levels of 2.0 milligrams per deciliter or higher were considered to have renal insufficiency. About 70 percent of patients in both groups received chronic diuretic therapy.
The study found that both renal insufficiency and diuretic use were associated with higher death rates and longer hospital stays. Patients with renal insufficiency who were taking diuretics had a mortality rate of 7.8 percent, while those who were not taking diuretics had a mortality rate of 5.5 percent. Similarly, patients with normal kidney function who were taking diuretics had a mortality rate of 3.3 percent while those who weren't taking diuretics had a mortality rate of 2.7 percent.
Patients with the greatest renal insufficiency in the ADHERE registry who were receiving long-term diuretic treatment experienced the highest mortality rates. At any degree of impairment of kidney function, patients receiving long-term diuretic treatment had a higher mortality rate than those who weren't receiving diuretic therapy.
Patients receiving chronic diuretic treatment also experienced longer hospital stays, on average. The average hospital stay ranged from 5.5 days for patients with low creatinine levels not receiving chronic diuretic therapy to 6.9 days for patients with elevated creatinine levels receiving chronic diuretic therapy.
The researchers who conducted this study concluded that diuretics should be used with caution in heart failure patients who have renal insufficiency. An alternative to diuretics is a relatively new nonpharmacologic procedure called ultrafiltration, which involves filtering patients' blood outside the body to remove excess fluid.
For more information on diuretics and heart failure, please take a look at the links on the next page.
More Great Links
- Bart B, Boyle A, Bank AJ, et al. The RAPID Study: Ultrafiltration versus usual care for hospitalized patients with heart failure: the Relief for Acutely Fluid-Overloaded Patients With Decompensated Congestive Heart Failure. J Am Coll Cardiol. 2005;46:2043-2046.
- Butler J, Forman DE, Abraham WT, et al. Relationship between heart failure treatment and development of worsening renal function among hospitalized patients. Am Heart J. 2004;147:331-338.
- Clark WR, Paganini E, Weinstein D, et al. Extracorporeal ultrafiltration for acute exacerbations of chronic heart failure: report from the Acute Dialysis Quality Initiative. Int J Artif Organs. 2005;28:466-476.
- Costanzo MR, Guglin ME, Saltzberg MT, et al. The UNLOAD Study: Ultrafiltration versus intravenous diuretics for patients hospitalized for acute decompensated heart failure. J Am Coll Cardiol. 2007; 49:675-683. http://www.unloadstudy.com
- Costanzo MR, Saltzberg M, O'Sullivan J, et al. The EUPHORIA Study: Early ultrafiltration in patients with decompensated heart failure and diuretic resistance. J Am Coll Cardiol. 2005;46:2047-2051.
- Davis RC, Hobbs FD, Lip GY. ABC of heart failure. History and epidemiology. BMJ. 2000;320:39-42.
- Domanski M, Norman J, Pitt B, et al. Diuretic use, progressive heart failure, and death in patients in the Studies Of Left Ventricular Dysfunction (SOLVD). J Am Coll Cardiol. 2003;42:705-708.
- Eshaghian S, Horwich TB, Fonarow GC. Relation of loop diuretic dose to mortality in advanced heart failure. Am J Cardiol. 2006;97:1759-1764.
- Mehta RL, Pascual MT, Soroko S, et al. Diuretics, mortality, and nonrecovery of renal function in acute renal failure. JAMA. 2002;288:2547-2553.
- Neuberg GW, Miller AB, O'Connor CM, et al. Diuretic resistance predicts mortality in patients with advanced heart failure. Am Heart J. 2002;144:31-38.
- Silverstein ME, Ford CA, Lysaght MJ, et al. Treatment of severe fluid overload by ultrafiltration. N Engl J Med. 1974;291:747-751.
- Ventura HO, Mehra MR. Bloodletting as a cure for dropsy: heart failure down the ages. J Card Fail. 2005;11:247-252.
- Walsh AC, Moyes A. Intractable congestive heart failure successfully treated with Southey tubes. Can Med Assoc J. 1964;90:1375-1376.