(USA TODAY) -- Researchers have identified gaps in the quality of heart failure care provided to thousands of patients by cardiologists who don't always follow treatment guidelines.

The study of cardiologists in 167 community practices serving nearly 35,000 outpatients first identified the omissions and then sought to close them using a package of educational workshops, decision-support tools and reminders. The effort proved a success, says lead researcher Gregg Fonarow of UCLA.

"This is really the first true test of dedicated practice performance improvement in an outpatient setting," Fonarow says.

But the study also promises to be controversial, doctors say, because it promoted a boost in the use of implanted devices called cardioverter-defibrillators made by study sponsor Medtronic.

An estimated 5 million Americans have heart failure, a progressive weakening of the heart muscle. Recent advances in treatment have dramatically slowed the heart's decline and reduced the death rate.

Evidence suggests cardioverter-defibrillators have played an important role. A major study has shown they can cut the heart failure death rate by nearly 25% over medical therapy, a result that prompted Medicare to cover the $30,000 to $40,000 implantation procedure.

Researchers are divided about the benefits of implantation, partly because the devices are costly and it's still unclear which patients get the most benefit.

Lynne Warner Stevenson, a heart failure expert at Brigham and Women's Hospital in Boston, noted that the study's biggest effect was to significantly increase the use of the "most controversial" therapy.

Fonarow's study, released Monday by the journal Circulation, says it was designed only to make sure doctors follow "evidence-based" guidelines for care released by the American Heart Association, the American College of Cardiology and key specialty groups.

Researchers supplied participating doctors a detailed analysis of how closely they followed the guidelines and a package of performance improvement tools. After two years, the researchers found:

*The use of beta-blocker drugs rose from 86% to 92%.

*The use of pacemakers to coordinate the heart's contractions rose from 37% to 66%.

*The use of cardioverter-defibrillators rose from 50% to 78%.

*Heart failure patient education -- on key topics such as diet and medication -- rose from 60% to 72%.

Stevenson, author of an accompanying commentary, says "it's very clear" the approach worked, though there's no evidence yet of reduced deaths and hospitalizations. "Doing more," she cautions, "is not necessarily doing better."

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