Heart-failure patients given AstraZeneca Plc's Crestor and standard drugs are just as likely to have heart attacks and strokes or die of cardiovascular problems as those on standard therapy alone, researchers said on Monday.

The news is a blow for Britain's second-biggest drug company, which had hoped to establish Crestor as the first cholesterol-lowering statin to show clear benefits in treating elderly patients with the chronic heart condition.

A successful result could have added $1 billion to U.S. revenues alone, according to industry analysts. But many had thought proving the drug's benefits would be tough. Crestor sold $2 billion worldwide in the first nine months of 2007.

Results of a 5,000-patient study showed Crestor was no better than placebo, although it did cut levels of bad LDL cholesterol and C-reactive protein -- an inflammatory marker -- and reduced hospitalisations for cardiovascular causes.

Why those benefits did not translate into lower rates of heart attack and death was not clear, John Kjekshus of the University and Oslo and colleagues told the annual meeting of the American Heart Association in Orlando.

AstraZeneca said it was possible the study failed to show statistical significance because the main cause of death was not acute coronary ischaemia, where statins have been shown to help, but instead was irreparable damage to failing heart muscle.

QUESTIONS REMAIN

Frederick Masoudi of the Denver Health Medical Center in Denver, Colorado, said in an online commentary in the New England Journal of Medicine that several uncertainties meant doctors should not change medical practice for now.

Although the results suggest there was no benefit on the primary outcome ... the study ends up raising almost more questions than it answers, he said in a telephone interview.

One should not rush to take (heart failure) patients like these off statins, he added.

Heart failure is a hard-to-treat condition in which the weakened heart cannot pump enough blood to meet the body's need for oxygen, causing shortage of breath and other problems. It is a leading cause of hospitalisation among the elderly.

Although Crestor's cholesterol-lowering ability has long been documented, the so-called CORONA study was the first to test whether the 4-year-old drug, which is known generically as rosuvastatin, actually improved patient outcomes.

All patients were given a number of drugs considered optimal therapy for heart failure -- including diuretics, beta blockers and blood-pressure medicines. In addition, some were also given a daily dose of 10 milligrams of Crestor.

After 33 months of treatment, 692 patients in the Crestor group had heart attacks, strokes or died of cardiovascular complications, against 732 of those who took standard treatments alone. The difference was not statistically significant.

Rival statins, including Pfizer Inc's Lipitor and Merck & Co's Zocor, have previously shown an ability to reduce the risk of strokes and heart attacks in other population groups by up to 30 percent.

But no statin has before been tested to assess its ability to protect heart-failure patients from such long-term health consequences, AstraZeneca officials said. In fact, trials of statins have traditionally excluded heart-failure patients.

Heart failure develops in an estimated 1 percent of the population, most commonly among the elderly. (Writing by Ben Hirschler; Editing by Quentin Bryar)

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