*

In two large studies of heart attack survivors,

beta-blocker

drugs benefited those with mildly impaired heart function

*

Contradictory trial results seen in patients without heart

dysfunction

*

More data on beta-blockers in patients with normally

functioning

hearts expected in November

By Nancy Lapid

Aug 30 (Reuters) - A decades-old pill remains helpful

for heart attack patients even with modern treatments that can

prevent lasting damage to heart muscle, two large trials have

shown.

Still unclear is whether all patients, or only some, benefit

from so-called beta-blocker drugs, which are typically

prescribed to everyone after a heart attack.

Two sharply contradictory reports were presented on Saturday

at a large cardiology meeting in Madrid and published in The New

England Journal of Medicine.

"It is not unusual for trials to yield different results,"

said Dr. Borja Ibanez of Centro Nacional de Investigaciones

Cardiovasculares Carlos III in Madrid, who led one of the

trials.

"Somewhat uncommon is to see two trials with apparently

divergent findings presented on the same day."

Most important, Ibanez said, is the finding both teams agree

on, which is that beta-blockers reduce the combined risk of

another heart attack, heart failure, or death in patients

without heart failure but with mildly impaired heart function.

The question is whether the pills are beneficial or useless

for those with normally functioning hearts, who account for

about 80% of patients after a first heart attack.

Beta-blocker manufacturers include Mylan, Novartis,

Pfizer ( PFE ), Abbott, Teva Pharmaceutical Industries

, Amneal Pharmaceuticals ( AMRX ), Sun Pharmaceutical

Industries, Lupin, ANI Pharmaceuticals ( ANIP ), and

Eagle Pharmaceuticals ( EGRX ).

The drugs work by inhibiting the hormones epinephrine and

norepinephrine, thereby lowering heart rate and blood pressure,

decreasing the workload on the heart and reducing its oxygen

demand.

Both new trials involved heart attack survivors whose hearts

were still contracting normally, that is, the left ventricle was

pumping out at least 40% of its blood with each beat. Both

trials followed patients for roughly 3.5 years.

Among 5,574 volunteers in the BETAMI-DANBLOCK study from

Norway and Denmark, the drugs showed a clear benefit. Patients

randomly assigned to receive beta-blockers had a 15% lower risk

of death or major adverse cardiovascular event, particularly a

repeat heart attack, compared to patients not taking these

pills, investigators found.

But among the 8,438 participants in the REBOOT trial

conducted in Italy and Spain, beta-blockers had no effect on the

incidence of death from any cause, a repeat heart attack, or

hospitalization for heart failure, according to a separate

report.

Some of the difference may be due to the fact that patients

didn't all receive the same beta-blockers, and the Scandinavian

patients might have been more prone to adverse events because

they were slightly older than patients in Spain and Italy and

more of them had mild heart dysfunction, said Dr. Dan Atar of

the University of Oslo, who led one of the trials.

Among female participants in REBOOT, those taking

beta-blockers - particularly those with good heart function

receiving higher doses - had more adverse outcomes than women

not taking the drugs, researchers reported in the European Heart

Journal.

In REBOOT, researchers did see a lower rate of new heart

attacks, heart failure, or death with beta-blocker use by

patients with mildly reduced heart function, as indicated by a

left ventricular "ejection fraction" between 40% and 49%.

The effect in this subgroup was confirmed in an analysis of

data pooled from REBOOT, BETAMI-DANBLOCK, and a Japanese trial,

according to a report published in The Lancet.

The message for cardiologists, Ibanez said, is "We can now

state with confidence that beta-blockers are beneficial" in

patients with mildly impaired heart function, and "there remains

reasonable uncertainty about their benefit" in patients with

normally functioning hearts.

Atar said an analysis looking specifically at beta-blocker

use by patients with normal heart function will be presented at

a U.S. cardiology meeting in November.