American Heart Association
Scientific Sessions Presentation: Emory Findings Dispute Previous
Studies Linking High Volume of Percutaneous Coronary Interventions
To Better Patient Outcomes
CHICAGO -- Past studies have concluded that patients undergoing percutaneous
coronary interventions (PCIs) in hospitals performing a high volume
of these procedures were less likely to die or to need urgent coronary
bypass graft surgery (CABG). In 2001, in fact, the American College
of Cardiology/ American Heart Association (ACC/AHA) Task Force increased
the minimum annual volume requirement for hospitals performing percutaneous
coronary interventions (PCIs) to 400 in response to studies demonstrating
an inverse association between volume and outcomes.
However, a study presented
today at the American Heart Association's Scientific Sessions by Emory
cardiology fellow Sean C. Beinart, MD, disputes the conclusions of previous
studies -- and raises the possibility hospital PCI volume may not be
a good quality of care indicator.
"Our conclusions do not support
the current AHA/ACC policy on minimum PCI volume recommendations," says
Dr. Beinart, who analyzed the data for the Emory Center for Outcomes
Research (ECOR) study. "In addition, we found that PCI procedural volume
is not an independent predictor of mortality or urgent CABG."
The Emory research team (which
included Emory cardiologist and ECOR Director William Weintraub and
Elizabeth Mahoney, PhD, Assistant Professor of Medicine) studied data
provided with permission and support of the American College of Cardiology,
National Cardiovascular Data Registry (ACC-NCDR).
"The ACC-NCDR is the largest,
most regionally diverse contemporary PCI registry with unique ability
to examine the impact of facility volume on outcomes after adjusting
for many demographic, clinical, and angiographic variables," says Dr.
The Emory researchers evaluated
the mortality rates for specific sites grouped by PCI volume and found
that over half of the low volume sites had risk- adjusted mortality
rates that were lower than the overall mortality in the ACC-NCDR.
What factors could explain
why the new study's conclusions differ from those of previous studies?
Dr. Beinart points out that there was a lack of regional diversity and/or
the ability to adequately risk-adjust outcomes in earlier studies. In
addition, most were done before the wide use of stents, tiny metal sheaths
that help keep arteries open following PCI.
"Other facility based and
process indicators of quality need to be identified also, such as nurse
to patient ratios, " says Dr. Beinart. "And more adequate representation
of low volume sites are needed to make definitive conclusions."
The study was supported in
part by a grant from the American Heart Association.
The Emory Heart Center
is comprised of all cardiology services and research at Emory University
Hospital (EUH), Emory Crawford Long Hospital (ECLH) Carlyle Fraser Heart
Center, the Andreas Gruentzig Cardiovascular Center of Emory University
and the Emory Clinic. Ranked in the top ten of U.S. News & World Report's
annual survey of the nation's best Heart Centers, the Emory Heart Center
has a rich history of excellence in all areas of cardiology - including
education, research and patient care. It is also internationally recognized
as one of the birthplaces of modern interventional cardiology.