When life-threatening problems occur during angioplasty procedures, doctors may perform emergency coronary artery bypass graft surgery, but data from the Mayo Clinic indicates that need to send patients to emergency surgery has dropped sharply, according to a new study in the Dec. 6, 2005, issue of the Journal of the American College of Cardiology.
"Our review of almost 25 years of data on angioplasty suggests that there has been a dramatic reduction of almost 90 percent in the incidence of coronary artery bypass graft surgery following angioplasty; and this is despite the fact that more recently we are performing angioplasty on very high risk patients," said Mandeep Singh, M.D., F.A.C.C., from the Mayo College of Medicine in Rochester, Minnesota.
The researchers, including lead author Eric H. Yang, M.D., reviewed a unique registry of every angioplasty performed at the Mayo Clinic. The registry includes more than 23,000 cases and extends back to the first angioplasty procedure in 1979. Coronary angioplasty involves threading a catheter through blood vessels in order to re-open arteries that nourish the heart muscle, usually after a heart attack or severe chest pain. The procedure is an alternative to bypass surgery in which blood vessels taken from elsewhere in the body are used to re-route blood around a coronary artery blockage. It is also known as percutaneous coronary intervention or PCI.
Data from the Mayo registry were divided into three groups: the "pre-stent" era, 1979 to 1994 (8,905 patients); the "initial stent era," 1995 to 1999 (7,605 patients); and the "current stent era," 2000 to 2003 (6,577 patients).
"We knew there had been a reduction, but the magnitude of the reduction was a surprise to us," Dr. Singh said. "The bypass surgery rates, which were close to 3 percent, came down to 0.3 percent in the most recent time period."
Dr. Singh said the fact that angioplasty is being offered to sicker patients now makes the reduction even more remarkable. Patients requiring emergency surgery in the most recent study period had a higher prevalence of high blood pressure and heart failure, and they were more likely to have undergone previous procedures, compared to patients in the earlier study periods.
Dr. Singh said he believes stents may be responsible for much of the reduction in the rate of life-threatening problems during angioplasty procedures. Stents are tiny wire-mesh scaffolds that are inserted into the area of a coronary artery narrowing that has been opened up by a balloon or cutting device. He also pointed to other improvements in drug therapy and device technology that have made angioplasty safer and more successful.