Fractional Flow Reserve-Guided Versus Angiography-Guided Coronary Artery Bypass Graft Surgery

Study Questions:

What is the utility of fractional flow reserve (FFR) in guiding coronary artery bypass surgery (CABG)?


The authors retrospectively evaluated the outcome of 627 patients undergoing CABG from 2006 to 2010, and having at least one intermediate severity stenosis. In 429 patients, CABG was based solely on angiography (angiography-guided group), and in 198 patients, the decision to bypass was guided by FFR (FFR-guided group). In the FFR group, lesions with an FFR ≤0.80 were bypassed, whereas those with an FFR >0.80 were deferred and treated medically. The endpoint was major adverse cardiovascular events at 3 years, defined as the composite of overall death, myocardial infarction, and target vessel revascularization.


There was no difference in the rate of angiographic multivessel disease in the angiography-guided and FFR-guided groups (94.2% vs. 93.9%, p = 0.72). In the FFR-guided group, this was significantly downgraded after FFR measurements to 86.4% (p < 0.001 vs. before FFR), and was associated with a smaller number of anastomoses (3 [2-3] vs. 3 [2-4]; p < 0.001) and rate of on-pump surgery (49% vs. 69%; p < 0.001). At 3 years, there was no difference in major adverse cardiovascular events between the angiography-guided and FFR-guided groups (12% vs. 11%; hazard ratio, 1.03; 95% confidence interval, 0.63-1.69; p = 0.91). The FFR-guided group compared with the angiography-guided group had a significantly lower rate of angina (Canadian Cardiovascular Society class II-IV, 31% vs. 47%; p < 0.001).


The authors concluded that FFR-guided CABG results in a lower number of graft anastomoses and a lower rate of on-pump surgery compared with angiography-guided CABG. There was no difference in event rates during 36 months of follow-up.


The limitations of coronary angiography have been recognized for a long time (Topol EJ, Nissen SE. Circulation 1995;92:2333-42), but it is only recently that FFR guidance has become a routine part of clinical practice for guiding percutaneous coronary intervention. This study suggests that FFR of intermediate lesions can provide similar benefits in patients undergoing CABG. Bypassing intermediate lesions can result in more rapid progression of native vessel disease as well as accelerated graft failure, and the findings of this study thus make intuitive sense. The use of FFR does add cost, and the clinical and cost-effectiveness of this approach need to be validated in a randomized controlled trial before FFR ascertainment prior to CABG becomes a routine part of clinical practice.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Coronary Angiography, Canada, Coronary Artery Bypass

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