A device that performs ultrafiltration of blood, without requiring specialized nursing care or invasive central intravenous access, can reduce fluid overload in patients with congestive heart failure, according to a new study in the Dec. 6, 2005, issue of the Journal of the American College of Cardiology.
"We found that this form of ultrafiltration therapy was safe, effective and successfully applied to patients in a variety of hospital settings. Compared to patients receiving standard treatment with intravenous diuretics, patients undergoing ultrafiltration had more fluid removed in the first 24 and 48 hours and improved symptoms of heart failure and shortness of breath at 48 hours," said Bradley A. Bart, M.D., F.A.C.C., from the Minnesota Heart Failure Consortium in Minneapolis, Minnesota.
Patients admitted to the hospital with acute decompensated heart failure are suffering from symptoms primarily related to fluid build-up and congestion, including swelling around the feet and ankles, bloated abdomens, cough and shortness of breath.
The RAPID-CHF trial is the first randomized controlled trial of ultrafiltration for acute decompensated heart failure. As blood passes through the device, ultrafiltration removes water and some small molecules through a membrane, before the blood is returned to the patient.
Researchers randomly assigned 40 hospitalized patients to receive either usual care, including diuretic medicine in most cases, or a single eight-hour ultrafiltration treatment, in addition to usual care. The ultrafiltration was performed with a device that has been approved by the federal Food and Drug Administration for use outside of intensive care units and without specialized nursing or central intravenous access. The manufacturer of the device, CHF Solutions Inc., funded this study.
Ultrafiltration was successful in 18 of the 20 patients in the group. After 24 hours, an average of 4,650 milliliters of fluid had been removed from patients in the ultrafiltration group, compared to 2,838 ml among patients usual care group. Patients in the ultrafiltration group also lost more weight on average, 2.5 kilograms compared to 1.86 kg average for the usual care group. However, the difference was not statistically significant. Intravenous access was unsuccessful in one patient, and one patient could not be treated due to inability to withdraw blood from the catheter.
Diuretics have been used to treat fluid overload for over 50 years; but the drugs drain electrolytes from patients, including potassium and magnesium, and it can be difficult to determine the proper dose for each patient. A practical, safe and effective ultrafiltration device could be an attractive alternative to diuretics.
"Ultrafiltration has been available for many years. In the past, it has been reserved for heart failure patients who fail all traditional therapies, as a form of rescue therapy. Traditional ultrafiltration requires invasive central intravenous access, monitoring in an intensive care unit and specialized nursing care. The ultrafiltration device used in this study can be operated by standard hospital nurses outside the setting of the intensive care unit, does not require invasive central IV access and, in the RAPID-CHF trial, was used as an early treatment strategy rather than for rescue therapy," Dr. Bart said.
Dr. Bart noted that this was a feasibility study that enrolled only a small number of patients. A larger trial to compare the effectiveness of this ultrafiltration device with standard care, including diuretics, is underway, with results expected in the spring, Dr. Bart said.