Diuretics Linked to Increased Mortality in Heart Failure

March 09, 2004

Martha Kerr

Mar. 9, 2004 (New Orleans) — Caution should be used when prescribing diuretics for patients with heart failure, especially those who show signs of renal insufficiency, according to investigators with the Acute Decompensated Heart Failure National Registry (ADHERE), the world's largest heart failure registry in the world.

Maria Rosa Costanzo, MD, from Midwest Heart Specialists in Naperville, Illinois, presented the data here yesterday at the American College of Cardiology's 53rd annual scientific session.

ADHERE was launched in 2001 to track the management, outcomes, and resource utilization of patients with heart failure. It now holds data on 105,000 patients hospitalized with decompensated heart failure.

In this analysis, Dr. Costanzo and colleagues divided patients into two groups: those with creatinine levels less than 2.0 mg/dL and those with levels of 2.0 mg/dL or higher. Dr. Costanzo noted that the ADHERE investigators used a fairly low threshold to define renal insufficiency.

Dr. Costanzo reported that 70% of those without renal insufficiency and 72% of those with renal insufficiency received chronic diuretic therapy.

Elevated creatinine level and diuretics were associated with higher death rates and longer length of hospital stay, Dr. Costanzo reported. The mortality rate for patients with renal insufficiency who were receiving chronic diuretic therapy was 7.8% compared with 5.5% for those not receiving diuretics. For patients with normal renal function receiving diuretics, mortality was 3.3% compared with 2.7% for their counterparts.

The highest mortality rates in ADHERE occurred in patients with the highest creatinine levels who were receiving chronic diuretic therapy. But regardless of baseline renal function, mortality was higher in patients receiving chronic diuretic therapy than in patients not receiving long-term therapy.

Increased length of hospital stay was also directly correlated to diuretic use. Patients with low creatinine levels not receiving chronic diuretic therapy had a mean length of stay of 5.5 days compared with 6.9 days for patients with elevated creatinine levels receiving chronic diuretic therapy.

"We need to rethink treatment for patients with heart failure, that diuretics may not be the best idea for these patients," Dr. Costanzo told Medscape. "What we are seeing in clinical practice is a knee-jerk reaction for physicians to give patients with decompensated heart failure larger doses of diuretics and smaller doses of [angiotensin-converting enzyme] ACE inhibitors and beta-blockers. We would like to shift that paradigm. If you optimize ACE and beta-blocker therapy, patients will stabilize and may not need diuretic therapy at all."

Dr. Costanzo said she discharges her patients with heart failure with orders to take diuretics on an as-needed basis only. "We set fairly specific parameters on when to take them: for rapid weight gain, edema, and so on — and to stop taking them when those symptoms resolve."

Dr. Costanzo noted that with the ADHERE database, investigators can track the medications that heart failure patients are given over time. The most common diuretic prescribed was furosemide and other loop diuretics. With long-term use of these drugs, Dr. Costanzo pointed out that the kidney tries to compensate by increasing sodium resorption in the distal tubules. She recommended sequential glomerular blockade with diuretics in this patient population.

"The next step is to draw attention to the fact that practice needs to change," Dr. Costanzo said.

"These findings do not mean that diuretic therapy is causing the increase in mortality," cautioned Clyde Yancy, MD, professor of medicine at the University of Texas Southwestern Medical Center in Dallas, and a member of the scientific advisory committee for ADHERE.

"The first thing to do is recognize what is incontrovertible: that patients with heart failure and creatinine levels above 2 mg/dL have an increasing rate of events," Dr. Yancy told Medscape. "As the creatinine changes, the risk goes up."

"We need to refrain from saying that administration of diuretics per se is causing the increased risk, but to identify why the patient is on diuretics in the first place," Dr. Yancy said.

"These findings are compelling and provocative but not conclusive.... I would not impugn the use of diuretics at this time," Dr. Yancy added.

ACC 53rd Annual Scientific Session: Session 1069-114. Presented March 8, 2004.

Reviewed by Gary D. Vogin, MD

Martha Kerr is a freelance writer for Medscape.