CABG guided by fractional flow reserve (FFR) was associated with fewer grafts, anastomoses and on-pump surgeries compared with grafts guided by angiography, according to a study published online Aug. 28 in Circulation.

Between 2006 and 2010, researchers investigated more than 600 patients who had CABG at Cardiovascular Center Aalst in Aalst, Belgium. All participants had at least one intermediate stenosis.

They divided the patients into two groups. An angiography-guided (angio-guided) group included 429 patients whose CABG indication was based solely on the severity determined by angiography. The other group featured 198 patients who had an intermediate stenosis determined by FFR, with grafts performed in the presence of FFR less than or equal to 0.8.

“FFR is well established for patients undergoing percutaneous coronary intervention, yet little is known for candidates to CABG,” wrote the authors, led by Gabor Toth, MD, of Cardiovascular Center Aalst.

As the study’s primary outcome, the researchers determined the rate of major adverse cardiac events (MACE) for up to three years. The secondary outcomes were each of the MACE endpoints, as well as the number of graft anastomoses and the symptoms present at the last clinical assessment.

The rates of angiographic multivessel disease were similar in both groups—it was present in 94.2 percent of angio-guided patients and 93.9 percent of the FFR-guided patients. After FFR measurements, however, the rate decreased to 86.4 percent in the FFR-guided group.

The analysis also linked FFR to a significantly lower number of anastomoses, fewer grafts, a lower rate of on-pump surgery (49 percent vs. 69 percent) and a significantly lower rate of Class II-IV angina (31 percent vs. 47 percent). In addition, there was no difference in MACE between the groups after three years.

The findings, the authors wrote, highlight the ability of FFR to “interrogate each stenotic coronary artery and to unmask possible ischemia-producing stenoses.”

In an editorial, Harold Lazar, MD, of Boston Medical Center in Boston, wrote that FFR shows great promise, but “before changes are made in determining what vessels should be grafted during CABG based on FFR, larger prospective, randomized trials with longer follow-up will be needed to better understand the role of this technology.”