CABG Superior to PTCA in Patients with Diabetes
Patients with diffuse, multivessel disease may fare better with bypass surgery.
Patients with diabetes are at greater risk for cardiovascular disease, which places them in a patient subgroup that tends to benefit more from coronary artery bypass graft (CABG) rather than percutaneous transluminal coronary angioplasty (PTCA), according to Bernard Gersh, MD, Professor of Medicine at the Mayo Clinic.
In the PTCA era, randomized controlled trials have suggested that CABG and PTCA have roughly the same outcomes. While PTCA often leads to a higher rate of revascularization than that seen with CABG, there are often no differences in death, myocardial infarction (MI), quality of life or lost days of employment.
Initial strategy
“PTCA is a reasonable initial strategy unless your patient has a burning desire for CABG,” Gersh said.
However, Gersh said these trials have excluded patients with left main coronary artery disease, prior PTCA, prior CABG and recent MI. Nearly two thirds of the patients in these trials have had two-vessel disease and left ventricular ejection fraction higher than 55%.
“These patients are eligible for either procedure by protocol, but they in fact only represent about a fourth of the patients we have to treat,” Gersh said.
Lessons from BARI
Gersh said the BARI trial provides an important look into how patients with diabetes fare on either CABG or PTCA.
Ten-year follow-up shows that nondiabetic patients had a 78.2% survival rate after being treated with CABG and a 76.8% survival rate after being treated with PTCA (P = .5).
However, patients with diabetes had much different 10-year survival rates: 57.1% with CABG and 44.1% with PTCA (P = .012) (Figure).
“It was thought that restenosis may have been the explanation, but restenosis effects tend to occur in the first months rather than years [later],” Gersh said.
Gersh said people with diabetes may fare better with CABG, because they tend to display diffuse and multi-vessel disease.
In the BARI registry, where physicians and patients made treatment decisions rather than using a randomization protocol, the five-year mortality between PTCA and CABG in patients with diabetes was nearly identical (14.4% vs. 14.9%).
“This suggests that patients were treated appropriately, and therefore had similar outcomes,” Gersh said.
Although it is important not to treat patients with diabetes as a monolithic entity, it appears that they would benefit from CABG rather than PTCA, he said.