Functional assessment with fractional flow reserve (FFR) was not better than conventional angiography to guide complete revascularization in patients with multivessel lesions in a setting of ST-segment elevation myocardial infarction and successful primary angioplasty.
These results were published in the New England Journal of Medicine (NEJM) and presented during the American College of Cardiology (ACC) 2021 Congress.
The rate of major cardiovascular events was low and similar between both strategies at a one-year follow-up. This would jeopardize the cost-benefit relationship of FFR in infarction.
Randomized and registry evidence is robust regarding FFR superiority vs. angiography in patients with chronic coronary syndromes.
In an acute context (especially in ST-segment elevation infarction), the COMPARE-ACUTE and DANAMI3-PRIMULTI studies showed that FFR-guided complete revascularization was superior to culprit-vessel angioplasty alone.
There is little information on FFR-guided complete revascularization vs. angiography-guided revascularization in ST-segment elevation infarction.
FLOWER-MI received some criticism from experts. On the one hand, the low incidence of events could take away some of its statistical power; on the other, non-culprit lesions seem particularly significant. In this sense, they do not appear to be typical intermediate lesions where FFR guide showed the greatest benefit.
Another target of criticism was that operators performed the entire revascularization in the same procedure, something that is far from daily clinical practice.
These studies analyzed 1163 patients with acute myocardial infarction and multivessel lesion (mean age: 62.2 years) who underwent successful primary angioplasty in the culprit vessel randomized to FFR-guided vs. angiography-guided complete revascularization.
Angiography of non-culprit lesions was conducted in 66.2% of FFR-guided patients and in 97.1% of angiography-guided patients.
The primary endpoint (a composite of death, infarction, or unplanned revascularization requiring hospitalization) was reached in 5.5% of patients the FFR arm vs. 4.2% in the angiography arm, a non-significant difference (hazard ratio: 1.32; 95% confidence interval: 0.78 to 2.23; p = 0.31). The statistics for the separate components of the primary endpoint were also similar, and so were the secondary endpoints (stent thrombosis, antianginal medication, quality of life, and readmissions).
Original Title: Multivessel PCI Guided by FFR or Angiography for Myocardial Infarction.
Reference: Etienne Puymirat et al. N Engl J Med. 2021 May 16. Online ahead of print. doi: 10.1056/NEJMoa2104650. The FLOWER-MI Study Investigators.