Coronary bypass rates drop

Think of it as bypassing the bypass. U.S. heart patients have been less likely in the past decade to undergo surgery to install a substitute vessel around a clogged coronary artery, with many patients getting a less invasive alternative procedure.

Coronary bypass operations decreased by 38 percent per capita in U.S. adults between 2001 and 2008, researchers report in the May 4 Journal of the American Medical Association. Meanwhile, angioplasty procedures — in which a doctor threads a catheter to the heart to open a blockage using a balloon — have stayed nearly constant, with the per capita rate dipping only 4 percent over that time. These catheters nearly always deliver a coated mesh cylinder called a stent, which props open the vessel from the inside. The study’s authors calculated the rates by analyzing a national sample of more than 5,000 coronary fixes.

The new findings reflect changes in coronary care that have arisen since specially coated stents gained U.S. regulatory approval in 2003, says study coauthor Peter Groeneveld, an internist at the University of Pennsylvania School of Medicine and the Philadelphia Veterans Affairs Medical Center. Coatings have made stents less prone to clogging.

Stents have obvious advantages over surgery — a shorter hospital stay, less short-term risk of complications and lower cost. In the traditional bypass operation, doctors remove vessels from less-crucial parts of the body and graft them to the heart to shuttle blood around blocked coronary arteries.

The new data show stenting running ahead of bypass operations in 2008 by three-to-one, Groeneveld says. The original guidelines for stents recommend the procedure for people with one or two vessels blocked and neither occluding the large branch of the coronary artery called the left main, which supplies blood to three-fourths of the heart muscle.

But in the past decade, doctors have installed stents in thousands of people with three or more vessels blocked or who have a blocked left main. Using information from a heart patient database, Harold Dauerman, an interventional cardiologist at the University of Vermont, reported in 2007 with his colleagues that more than half of people with at least three vessels occluded were getting stents by 2005.

In 2009, a U.S.-European team compared stenting and bypass surgery in severe cases and reported in the New England Journal of Medicine that 13.5 percent of stented patients needed surgery for another blockage within a year. Only 5.9 percent of those getting coronary bypass surgery did. But another look at the same patients, in the March 17 New England Journal of Medicine, found that percentages of the patients free of chest pain at 12 months post-procedure were practically the same in the stent and bypass groups — 72 and 76 percent.

“There are quality-of-life issues that are relevant to patients,” Dauerman says. “Many patients prefer shorter hospitalization.” This mixed bag of evidence has led to a closer look at which procedure might be appropriate on a patient-by-patient basis, and doctors in Europe are currently testing the use of teams to decide a patient’s best course of action.