NATURE REVIEWS | CARDIOLOGY VOLUME 11 | NOVEMBER 2014

Nature Reviews Cardiology 11, 619 (2014); published online 16 September 2014; doi:10.1038/nrcardio.2014.140

Two studies published in association with the ESC Congress 2014 (FAME 2 in The New England Journal of Medicine and FAMOUS-NSTEMI in the European Heart Journal) were designed to assess the use of fractional flow reserve (FFR) to guide revascularization interventions in patients with stable coronary artery disease (CAD) or non-ST-segment elevation myocardial infarction (NSTEMI), respectively. Many patients with these conditions require revascularization therapy, such as percutaneous coronary intervention (PCI) or CABG surgery, to address myocardial ischaemia. Visual assessment by coronary angiography allows the detection of obstructive coronary artery events, but this method has limitations when accurate assessment of the physiological relevance of a lesion is needed. Alternatively, strong clinical data favour the use of fractional flow reserve (FFR)-guided revascularization when assessment of the functional importance of myocardial stenosis is recommended.

In the FAME 2 study, FFR was assessed in all stenoses that were detected using angiography, and patients with an FFR ≤0.80 in a major coronary artery were randomly allocated to undergo FFR-guided PCI plus medical therapy (n = 447), or to receive medical therapy alone (n = 441). The primary end point was defined as a composite of all-cause death, nonfatal myocardial infarction, or unplanned hospitalization followed by urgent revascularization within 2 years. Results show that the primary

CORONARY ARTERY DISEASE

Fractional flow reserve-guided management of CAD

outcome was less frequent in the PCI group compared with patients who received medical therapy alone (8.1% vs 19.5%; HR 0.39, 95% CI 0.26–0.57, P <0.001), owing to a lower rate of urgent revascularization. No significant differences were observed in the rates of myocardial infarction and death. These results show that FFR-guided PCI can prevent adverse events, but also “support other research that PCI, even when FFR-guided, cannot prevent death or myocardial infarction,” comments Dr William Weintraub from Christiana Care in Newark, DE, USA, who was not involved in these studies.

In the FAMOUS-NSTEMI trial, 350 patients with NSTEMI and at least one coronary stenosis ≥30% of the lumen diameter were randomly allocated to an FFR-guided group (n = 176, in which FFR was disclosed to the operator) or an angiography-guided group (n = 174, in which FFR was measured, but not disclosed to the operator). Patients in the FFR-guided group received medical therapy without revascularization more frequently than patients in the angiography-guided

group (22.7% vs 13.2%; P = 0.022), a difference also observed at 12 months (79.0% vs 86.8%; P = 0.054). Health outcomes and quality of life were similar in each group. “This suggests that FFR in NSTEMI patients can reduce [the number of] revascularization procedures,” adds Dr Weintraub, but these results “require confirmation in a larger trial”.

Both studies provide further evidence of the safety of FFR-guided management and inform on the clinical utility of this method. “Angiography does not do an adequate job of assessing flow-limiting lesions that are more likely to benefit from PCI. FFR can improve upon this [shortcoming],” concludes Dr Weintraub.

João H. Duarte

Original articles De Bruyne, B. et al. Fractional flow reserve-guided PCI for stable coronary artery disease. N. Engl. J. Med. doi:10.1056/nejmoa1408758 | Layland, J. et al. Fractional flow reserve vs. angiography in guiding management to optimize outcomes in non-ST-segment elevation myocardial infarction: the British Heart Foundation FAMOUS–NSTEMI randomized trial. Eur. Heart J. doi:10.1093/eurheartj/ehu338

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