Boston Scientific Taxus did not perform as expected in comparison to surgery. Image Source: New York Times

The SYNTAX trial that Boston Scientific undertook to prove the worth of drug-eluting stent (DES) procedures has conversely failed to meet its primary endpoint at one year, and shown that CABG is a preferable method for the sickest patients, according to results presented this week at the European Society of Cardiology (ESC) in Munich, Germany.

The SYNTAX (SYNergy Between PCI with TAXus and Cardiac Surgery) trial enrolled 1,800 patients in its randomized arm, and a multidisciplinary team, which included an interventional cardiologist and a cardiac surgeon, assessed all patients to determine if either PCI or CABG was the preferred option, according to the Natick, Mass.-based Boston Scientific.

The study, costing approximately $50 million, included 85 hospitals in the U.S. and Europe.

In the first head-to-head comparison of PCI versus bypass surgery, SYNTAX found no statistically significant difference in risk of death (4.3 vs. 3.5 percent) or heart attack (4.8 vs. 3.2 percent) at one year, according to the investigators. Overall, 17.8 percent of stent patients died, suffered a stroke or heart attack, or return for another operation, which compared with only 12.1 percent of bypass patients—stenting was statistically inferior to bypass surgery.

However, the risk of stroke alone was significantly greater for bypass surgery (0.6 percent for PCI vs. 2.2 percent for bypass). The researchers noted the significant decrease in the rate of stroke for patients treated with PCI as compared to CABG.

According to SYNTAX investigator, Friedrich Mohr, MD, from the University of Leipzig in Germany, and colleagues, said that the trial did not meet its primary endpoint at 12 months of major adverse coronary and cerebrovascular events, including death, MI, cardiovascular events and revascularization.

Mohr and his colleagues concluded that “in patients who are not candidates for PCI, surgical results are excellent. In patients who are not candidates for CABG, PCI is a viable option.”

“It's very encouraging for the future of coronary bypass,” Robert Guyton, MD, a heart surgeon at Emory University in Atlanta and former president of the Society of Thoracic Surgeons, told the Wall Street Journal. “It should alter treatment patterns in the United States, in some areas in which stenting has been utilized excessively.”

"The take-away message is that SYNTAX has extended the spectrum of care for a large number of patients with very complex coronary artery disease. For some, bypass surgery will still be the most appropriate option, but many more patients now have another choice," said SCAI Past-President Ted Feldman, MD, professor of medicine at Northwestern University School of Medicine in Chicago, director of the cardiac cath lab at Evanston Hospital in Chicago and SYNTAX steering committee member.