Heart failure patients have an increased risk for thrombosis-related events like stroke or heart attacks, but as the authors of the study point out in the American Heart Journal, "Just because patients are at increased risk of events does not mean that antithrombotic therapy is safe or effective."

And in fact, results from the Warfarin/Aspirin Study in Heart Failure (WASH) show that aspirin and warfarin provide no meaningful benefit to patients with heart failure.

"I am sure that with time the medical scientific community will come round to the view that the benefit/risk ratio for antithrombotic therapy in heart failure is unclear and that further placebo-controlled studies (as in WASH) will be necessary," lead author Dr. John G. F. Cleland from University of Hull, UK, told Reuters Health.

Cleland and his colleagues compared no antithrombotic therapy with aspirin or warfarin in 279 patients with heart failure requiring diuretic therapy.

There was no significant difference in rates of death, nonfatal heart attacks, or nonfatal stroke among the three groups, the authors report.

However, those participants assigned to aspirin therapy were twice as likely as patients on warfarin to be hospitalized or to die of a cardiovascular cause during the first 12 months of follow-up.

The three groups experienced similar numbers of serious adverse events, the researchers note, but aspirin patients were significantly more likely to have serious gastrointestinal events.

Minor bleeding complications were also more common in the aspirin and warfarin groups than in the no-antithrombotic group, the researchers found.

Treatment with multiple drugs "is a big problem in patients with heart failure," Cleland noted. "Treatments that are not shown to be effective should be withdrawn."

He added, "The data on aspirin in particular is worrying and suggests that any theoretical benefit is outweighed by real evidence of harm."

SOURCE: American Heart Journal, July 2004.