World’s Largest Observational Study of CABG v. PCI Reveals Overall Survival Advantage for Surgery in Medicare Populations

PRESS RELEASE -- March 27, 2012 – Today, at the American College of Cardiology’s (ACC) 61st Annual Scientific Session & Expo, investigators revealed the final results of the world’s largest observational study of long-term survival in patients undergoing heart bypass surgery (CABG) compared to patients undergoing coronary stent placement by percutaneous coronary intervention (PCI). In the ACC late-breaking clinical trials presentation, a progressively higher long-term survival advantage for CABG patients compared to PCI patients was presented in the overall results.

Funded by the National Institutes of Health (NIH), the ACCF-STS Database Collaboration on the Comparative Effectiveness of Revascularization Strategies (ASCERT) study is an unprecedented study that used the clinical databases of both The Society of Thoracic Surgeons (STS) and the American College of Cardiology (ACC). In order to obtain long-term follow up, patient records were also linked to data from the Centers for Medicare and Medicaid Services (CMS).

Led by principal investigators, Fred H. Edwards, MD (STS) and William S. Weintraub, MD (ACC), ASCERT looked at over 185,000 Medicare patients undergoing coronary revascularization from 2004 to 2008. In the overall results, first year survival favored stent placement. However, beyond the first year of revascularization, all patients showed a clear CABG survival advantage that progressively increased over time.

“The focus of the ASCERT study was on ‘real world’ Medicare patients,” said Fred H. Edwards, MD. “This study was carefully designed by both cardiologists and cardiothoracic surgeons to produce reliable results based on an exhaustive statistical analysis.”

“Previous state and regional observational studies have shown a long-term survival advantage for CABG over PCI. The ASCERT results confirm that the CABG survival advantage is also seen in a large nationwide population,” continued Dr. Edwards. “ASCERT now offers patients a comprehensive look at the comparative effectiveness of open heart surgery and stent procedures, with solid evidence of a survival advantage for surgery," concluded Dr. Edwards.

The CABG population for ASCERT was taken from the STS Adult Cardiac Surgery Database, the country’s premier clinical database that currently contains more than 4.5 million surgical records and represents an estimated 94 percent of all adult cardiac surgery centers across the United States.

The PCI population for ASCERT was taken from ACC’s National Cardiovascular Data Registry, the most comprehensive, outcomes-based quality improvement program in the United States representing over 10.6 million patient records.

Duke Clinical Research Institute was an integral part of the design team and provided detailed statistical analysis of the registry populations.

The funding for the ASCERT study was issued under the American Recovery and Reinvestment Act of 2009. This is the first time STS and ACC have collaborated in an NIH study. This study was funded by the National Institutes of Health’s National Heart, Lung and Blood Institute. This study will be simultaneously published in the New England Journal of Medicine and will be released online at the time of presentation.

The ASCERT TRIAL PRESENTATION took place during Session 308, Tuesday, March 27, 2012 from 8:00 a.m. – 9:30 a.m. at McCormick Place North, Hall B, in the Main Tent.

Note to Editors: For more information about the ASCERT study, or to arrange for an interview with Dr. Edwards via phone, contact Rachel Estrada at restrada [at] sts [dot] org or (312) 202-5865.

Founded in 1964, The Society of Thoracic Surgeons is a not-for-profit organization representing more than 6,300 surgeons, researchers, and allied health care professionals worldwide who are dedicated to ensuring the best possible outcomes for surgeries of the heart, lung, and esophagus, as well as other surgical procedures within the chest. The mission of the Society is to enhance the ability of cardiothoracic surgeons to provide the highest quality patient care through education, research, and advocacy. Learn more at