Expert Alert: Mayo study finds repeat coronary artery bypass grafting improves long-term survival

Expert Alert: Mayo study finds repeat coronary artery bypass grafting improves long-term survival.

When a coronary artery bypass grafting (CABG) patient needs a second surgery because of recurrent chest pain, more often than not it's a percutaneous coronary intervention (PCI), commonly known as coronary angioplasty with stents.

A study published in September in Mayo Clinic Proceedings says that a better option may be repeating the coronary artery bypass grafting operation. The cohort study, based on health records of 1,612 patients at Mayo Clinic from 2000 to 2013, finds that overall survival was increased with repeat coronary artery bypass grafting versus patients who underwent percutaneous coronary intervention.

Long-term survival was improved, especially when compared with percutaneous coronary intervention involving previous bypass grafts.

Coronary bypass surgery redirects blood around a section of a blocked or partially blocked an artery in the heart to improve blood flow. The procedure uses a healthy blood vessel from the patient's leg, arm or chest and grafts it beyond the blocked arteries in the heart. Percutaneous coronary intervention is a procedure to open blocked arteries, often by the placement of a wire mesh tube called a stent. Some stents are coated with medication to help keep the blood vessel open.

Most previous studies have found similar long-term survival with repeat coronary artery bypass grafting, compared with percutaneous coronary intervention. The Mayo Clinic study finds the survival at 10 years for repeat coronary artery bypass grafting patients reflected a 15% absolute improvement over matched patients who underwent percutaneous coronary intervention.

The findings have clinical significance because repeat coronary artery bypass grafting often is not considered, says Chaim Locker, M.D., a Mayo Clinic cardiovascular surgeon and the study's lead investigator. "Currently, PCI is considered by many to be the first option for patients who need repeat surgery after a previous coronary artery bypass grafting," Dr. Locker says. "However, our data demonstrate a clear overall survival benefit of repeat CABG."

The study notes that the number of patients undergoing repeat coronary artery bypass grafting has declined dramatically in recent years. While the risk for early mortality is higher for repeat coronary artery bypass grafting patients, long-term mortality risk was reduced by 28% versus percutaneous coronary intervention patients in the Mayo study.

"This study, which uses a more current cohort of patients than previous studies and compares the use of contemporary surgical techniques versus stenting, demonstrates a clear overall survival benefit for repeat CABG patients," Dr. Locker says. "This potential advantage should be considered among treatment options after a previous bypass surgery." This is especially true for patients who require treatment of a diseased saphenous (leg) vein coronary bypass graft, he says.