Heart bypass surgery appears to carry higher long-term survival rate

Patients with coronary heart disease and their doctors have long been challenged by the decision of whether to pursue bypass surgery or opt for the less-invasive percutaneous coronary intervention (PCI, which includes stenting and balloon angioplasty). New evidence reveals bypass surgery appears to carry a higher long-term survival rate, according to research presented today at the American College of Cardiology's 61st Annual Scientific Session. The Scientific Session, the premier cardiovascular medical meeting, brings cardiovascular professionals together to further advances in the field.

The study analyzed health outcomes of 190,000 patients across the United States to compare the results of bypass surgery to those of PCI. The study found that patients who underwent PCI had a higher death rate in the first four years after treatment than those who had opted for bypass surgery (20.8 percent and 16.41 percent, respectively).

"Our study is the most general one ever done because it uses data from across the whole country. It is also much larger than any other study," said William S. Weintraub, MD, chair of cardiology at Christiana Care Health System and the study's lead investigator. "Combining data from several large databases, we found that survival was better with coronary surgery than percutaneous coronary intervention."

Dr. Weintraub cautioned that the results do not mean bypass surgery is best for every patient. "It does push the needle toward coronary surgery, but not overwhelmingly so," said Dr. Weintraub. "When we're recommending coronary surgery to patients, even though it is a bigger intervention than PCI, we can now have a little more confidence that the decision is a good one."

Coronary heart disease - the leading cause of death in the United States - occurs when a fatty buildup narrows or blocks the heart's arteries. In bypass surgery, a surgeon opens the patient's chest cavity and creates a detour around the blocked artery using a vein from another part of the body. In PCI, also known as angioplasty, a surgeon threads instruments through a small incision to clean out the blockage and insert a wire stent, or tube, to keep the artery open (a small balloon may also be used to open the artery).

While some previous studies have suggested the two treatments have similar long-term outcomes, others have also shown better outcomes with bypass surgery. Patients and doctors tend to choose the less-invasive PCI when both treatments are an option.

The researchers combined patient data from the American College of Cardiology Foundation CathPCI database, the Society of Thoracic Surgeons CABG database and the Medicare claims database to compare survival rates among 86,000 bypass surgery patients and 103,000 PCI patients who underwent treatment from 2004-2008. Dr. Weintraub says that a major limitation of observational studies, such as this one, is that the groups may not have the same level of risk, and so it is possible that the worse outcomes in the PCI patients were related to these patients being sicker overall. "We used sophisticated statistics to account for different levels of risk, but there may be differences between the two groups that we could not account for," he said.

The large number of cases allowed the researchers to compare results across many subgroups. "What was a surprise to us all was how consistent the data were no matter what analytic approach we used, and how consistent the data were across all subgroups," said Dr. Weintraub. "Survival was better with coronary surgery for all patient subgroups. This study should help inform decision making concerning the choice of revascularization in patients with stable ischemic heart disease."