According to the American Heart Association, one in five people 40 years of age or older will develop some form of heart failure in their lifetime. Plus, as one gets older, the risk of heart failure increases; 10 percent of people older than 75 years of age have been diagnosed with heart failure -- and, because people are living longer, the incidence of heart failure is growing.
As heart function declines in the course of heart failure, the heart is unable to pump out all of the blood that enters its chambers and fluid starts building up in the lungs, arms, legs and abdomen. This condition, called fluid overload, is frequently associated with heart failure; in fact, heart failure is the leading cause of fluid overload.
Patients with heart failure and fluid overload are traditionally treated with diuretic drugs. However, studies have shown that this treatment is often ineffective. Data from the Acute Decompensated Heart Failure National Registry (ADHERE) show that most hospitalizations for heart failure are due to fluid overload in patients for whom oral diuretics are no longer effective. Even though intravenous diuretic drugs are used in 90 percent of hospitalized heart failure patients, a significant percentage of these patients still have symptoms of fluid overload when they leave the hospital. In fact, many of these patients must be hospitalized again for additional treatment.
In more than one out of four heart failure patients who are taking diuretics, these medicines lose their effectiveness before a normal fluid balance has been restored -- a condition known as diuretic resistance. When this happens, doctors may adjust the dose of the diuretic or change the timing of the dose. In some cases, it works better to give the diuretic continuously through a vein instead of giving it in individual oral doses. A second treatment approach uses combinations of different diuretic drugs that act on the kidneys in different ways, with the idea that different diuretic drugs acting together may produce an improved diuretic response. However, doctors have learned that treatments for diuretic resistance have limited success.
Concerns have been raised about the safety of the use of loop diuretics (a powerful type of diuretic drug) to treat fluid overload in heart failure patients, in addition to concerns about their effectiveness. According to a number of recent studies, the chronic use of loop diuretics in this patient population results in an increased risk of death.
Ultrafiltration is another treatment that has been shown to reduce fluid overload. In the past, doctors reserved ultrafiltration for fluid-overloaded heart failure patients who tried (and failed with) diuretics. However, a group of scientists conducted an experimental study to find out if ultrafiltration would work well in heart failure patients with fluid overload and diuretic resistance -- before intravenous diuretic drugs. They named the study the EUPHORIA trial (Early Ultrafiltration Therapy in Patients with Decompensated Heart Failure and Observed Resistance to Intervention with Diuretic Agents).
On the next page we'll find out what the EUPHORIA trial revealed about treatment for fluid overload.