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.