RAPID-CHF Study Overview

The RAPID-CHF study compared the safety and effectiveness of two heart-failure treatments -- ultrafiltration and diuretic drugs. See pictures of heart health.

A growing number of people today suffer from heart failure -- people are living longer and the risk of developing this condition increases with age. According to the American Heart Association, more elderly people are hospitalized for heart failure than for any other condition. The National Institutes of Health estimates that one out of every 100 people over the age of 65 will be diagnosed with heart failure.

In the United States, more than a million heart failure patients are admitted to the hospital each year -- resulting in health care costs of nearly $29 billion.


In heart failure, the heart's muscular contractions become weaker and less effective over time. When this happens, there's a tendency for excess fluid to build up in the body. Doctors traditionally use diuretic drugs, which help flush fluids from the body, to treat heart failure patients who have symptoms of fluid overload.

There are several different types of diuretic drugs -- loop diuretics are the strongest. But unfortunately, diuretics are often not effective in relieving the symptoms of fluid overload in heart failure patients. In fact, data show that most hospitalizations for heart failure are fluid-overloaded patients for whom oral diuretic drugs are no longer working. Even though 90 percent of patients in these circumstances are treated with intravenous diuretic drugs, a significant percentage of them fail to achieve relief upon release from the hospital, and many of them are readmitted to the hospital later.

Diuretic resistance is a term for the condition from which some of these patients suffer. It happens when diuretics don't flush out enough excess fluid, and it's particularly likely to occur in patients with moderate or severe heart failure.

Ultrafiltration is an alternative to diuretics. Researchers designed a clinical study to compare the safety and efficacy of ultrafiltration with that of diuretic drugs. The official name of the study was the Relief for Acutely Fluid Overloaded Patients with Decompensated Congestive Heart Failure trial, which was nicknamed the RAPID-CHF study. We'll discuss the results of the study on the next page.

Results of the RAPID-CHF Study

The RAPID-CHF study was a randomized controlled trial of 40 heart failure patients in six hospitals in Minneapolis/St. Paul. The patients were divided into two groups of 20: one group received a single eight-hour session of ultrafiltration, and the other group received the standard treatment for fluid overload in heart failure patients, which included 24 hours of diuretic treatment.

After 24 hours, significantly more excess fluid was removed from the patients who had received ultrafiltration.


Unlike diuretic treatment, ultrafiltration was not associated with significant changes in heart rate, blood pressure or electrolytes (small molecules, such as sodium, in our bodily fluids). At 38 hours, shortness of breath and other symptoms of fluid overload (such as swelling of the legs, feet or abdomen) were significantly improved in patients in the ultrafiltration group.

The researchers concluded that ultrafiltration is safe, well-tolerated and associated with effective fluid removal and relief of fluid-overload symptoms. They also concluded that there's no need to delay ultrafiltration therapy until diuretics fail. Patients who received ultrafiltration had an increased responsiveness to subsequent diuretic therapy and increased sodium excretion, despite decreasing doses of diuretics.

To learn more about fluid overload and ultrafiltration, take a gander at the links on the next page.

Related Articles

More Great Links


  • Adams KF, Lindenfeld J, Arnold JMO, et al. Heart Failure Society of America (HFSA) 2006 Comprehensive Heart Failure Practice Guideline. J Cardiac Failure 2006;12:e1-e122.
  • Agostoni P, Marenzi G, Lauri G, et al. Sustained improvement in functional capacity after removal of body fluid with isolated ultrafiltration in chronic cardiac insufficiency: failure of furosemide to provide the same result. Am J Med. 1994;96:191-199.
  • Agostoni P, Marenzi GC, Pepi M, et al. Isolated ultrafiltration in moderate congestive heart failure. J Am Coll Cardiol. 1993;21:424-431.
  • Ahmed A, Young JB, Love TE, et al. A propensity-matched study of the effects of chronic diuretic therapy on mortality and hospitalization in older adults with heart failure. Int J Cardiol. 2007. [Epub ahead of print].
  • 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.
  • 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.
  • Elkayam U, Hatamizadeh P, Janmohamed M. The challenge of correcting volume overload in hospitalized patients with decompensated heart failure. J Am Coll Cardiol. 2007;49:684-686.
  • Eshaghian S, Horwich TB, Fonarow GC. Relation of loop diuretic dose to mortality in advanced heart failure. Am J Cardiol. 2006;97:1759-1764.
  • Jaski B, Ha J, Denys BG, et al. The SAFE Study: Peripherally inserted veno-venous ultrafiltration for rapid treatment of volume overloaded patients. J Card Fail. 2003;9:227-231.
  • Marenzi G, Lauri G, Grazi M, et al. Circulatory response to fluid overload removal by extracorporeal ultrafiltration in refractory congestive heart failure. J Am Coll Cardiol. 2001;38:963-968.
  • Mehta RL, Pascual MT, Soroko S, et al. Diuretics, mortality, and nonrecovery of renal function in acute renal failure. JAMA. 2002;288:2547-2553.
  • Pepi M, et al. Sustained cardiac diastolic changes elicited by ultrafiltration in patients with moderate congestive heart failure: pathophysiological correlates. Br Heart J. 1993;70:135-140.