Routine FFR in Patients with Acute Coronary Syndrome?

Fractional flow reserve (FFR) has proven to be superior to angiography as a guide to revascularization due to a significant reduction in the number of both long-term and short-term events. Furthermore, deferring treatment of lesions without evidence of ischemia offers an excellent prognosis. Many studies including mostly stable patients showed a significant degree (as high as 40%) of patient reclassification and changes to the original strategy.

However, invasive management with angiography and angioplasty has shown the highest potential to reduce hard events (even death) among patients with acute coronary syndrome (ACS), the patient group that most requires management optimization nowadays.

There is few evidence supporting the use of FFR as a strategy for optimal patient revascularization in patients with acute coronary syndrome, particularly those with non-ST-elevation ACS.

Read also: “Minimum Appropriate Follow-Up Reduces Mortality After Endoprosthesis Implantation”.

Multicenter study PRIME-FFR (POST-IT y R3F Integrated Multicenter Registries – Implementation of FFR in Routine Practice) sought to assess how the original strategy can be modified using routine FFR in patients with acute coronary syndrome and whether revascularization deferral is as safe in these patients as it is in stable subjects.

From 1983 patients, in whom FFR was prospectively used to guide treatment, 533 were admitted with non-ST-elevation acute coronary syndrome.

FFR was performed in 1.4 lesions per patient, mostly in the anterior descending artery (58%), with a mean percent stenosis of 58 ± 12% and a mean FFR of 0.82 ± 0.09.

Read also: “Polymer-Free DES Also Show Efficacy in Anticoagulated Patients with High Risk for Bleeding”.

In patients with acute coronary syndromes, reclassification by FFR was similar to that in stable patients (38% versus 39%; p = NS). The pattern of reclassification was different with less patients with ACS reclassified from revascularization to medical treatment compared with those in the stable cohort (p = 0.001).

At one year, the prognosis for ACS patients reclassified (FFR against angiography) was as good as that for patients with FFR concordant with angiography, with no difference in major cardiovascular events (8.0% versus 11.6%; p = 0.20) or symptoms (92.3% versus 94.8% angina free; p = 0.25). These findings were confirmed upon assessment of the non-ST-elevation ACS culprit lesion artery.

In 6% of patients, in whom the information derived from FFR was disregarded, an increase in the rate of cardiovascular events was observed when compared to the global population.

Conclusion

Routine assessment with FFR as part of the decision-making process in patients with non-ST-elevation acute coronary syndrome was associated with a high reclassification rate (38%). A strategy of revascularization guided by FFR was divergent from that suggested by conventional angiography and turned out to be safe even with non-significant FFR and revascularization deferral.

Editorial

So far, this is the largest study reporting the use of FFR in non-ST-elevation acute coronary syndrome patients.

Reclassification resulted in a higher proportion of revascularized patients and this phenomenon was observed especially in ACS patients (+26% vs. +7%; p = 0.03). This led to a higher proportion of patients receiving angioplasty or surgery after FFR in the ACS group compared with the chronic and stable group (51.1% versus 45.2%; p = 0.02). Reclassified patients presented more frequently 2- or 3-vessel lesion (p < 0.001), lesion in the anterior descending artery (p < 0.006), and, obviously, lower FFR (p < 0.001).

This study confirms what was observed in the R3F and POST-IT studies, in which routine FFR did not necessarily lower the rates of revascularized patients, as opposed to popular belief.

Original title: Impact of Routine Fractional Flow Reserve on Management Decision and 1-Year Clinical Outcome of Patients with Acute Coronary Syndromes. PRIME-FFR (Insights from the POST IT [Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease] and R3F [French FFR Registry] Integrated Multicenter Registries – Implementation of FFR [Fractional Flow Reserve] in Routine Practice).

Reference: Eric Van Belle et al. Circ Cardiovasc Interv. 2017;10:e004296.

We are interested in your opinion. Please, leave your comments, thoughts, questions, etc., below. They will be most welcome.