After a 5-year follow-up, and for the first time, functional assessment with fractional flow reserve (FFR) showed clear benefit for a hard endpoint: acute myocardial infarction.
Use of FFR in patients with stable coronary artery disease so as to identify hemodynamically significant lesions in order to restrict angioplasty treatment to them has long-term benefits compared with optimal medical treatment, according to results from two studies presented at EuroPCR 2018. These were the FAME 2 trial (simultaneously published in the New England Journal of Medicine), with a 5-year follow-up, and the SCAAR registry, which tracked patients through 10 years.
According to FAME 2, FFR managed a persistent advantage over time, despite substantial crossover from the optimal medical treatment arm to the angioplasty arm. Current results allow us to explain such crossover: simply put, for some lesions, the best medical treatment is not enough.
Read also: Routine FFR/iFR Reclassifies Treatment Strategies in Half of Cases.
The message is clear: physiological assessment of lesions with FFR prevents events by ensuring that significant plaque gets treatment, and also prevents unnecessary procedures in lesions that do not require them. As a matter of fact, 35% of all lesions considered as ‘severe’ by interventional cardiologists upon analyzing angiography results were reclassified as non-significant after a functional assessment.
The 5-year results for FAME 2 represent the final results for that study, which enrolled 1220 patients with stable coronary disease and angiographically significant lesions. FFR was assessed in all target lesions; 73% of patients had at least one functionally significant lesion of ≤0.8. Patients were randomized to optimal medical treatment plus angioplasty for lesions with FFR ≤0.8 vs. optimal medical treatment alone. Patients without functionally significant lesions were enrolled in a registry and received optimal medical treatment, like all other patients.
Ultimately, 888 patients were randomized; 447 patients were placed in the angioplasty group and 441 in the medical treatment group.
Read also: The diagnostic performance of the iFR makes the FFR tremble.
At 5 years, the composite endpoint of death, infarction, or urgent revascularization was less significantly less common in the angioplasty group (13.9% vs. 27.0%; hazard ratio [HR]: 0.46; 95% confidence interval [CI]: 0.34-0.63).
Patients who lacked functionally significant lesions and were consequently enrolled in the registry presented a 15.7% rate of combined events, very similar to the 13.9% rate for the angioplasty group.
The difference in combined events was mainly driven by the need for urgent revascularization (6.3% of angioplasty patients needed one vs. 21.1% of medical treatment patients; HR: 0.27; 95% CI: 0.18-0.41).
The novelty in the 5-year follow-up (something that is being reported for the first time in a study assessing FFR as a decision-making tool) is a reduction in the rates of infarction (8.1% for the angioplasty group vs. 12% for the medical treatment group; HR: 0.66; 95% CI: 0.43-1.00; p = 0.049). The difference was only significant for spontaneous infarction (HR: 0.62; p = 0.04), not periprocedural infarction.
Mortality was similar between the two groups and symptom relief, which at 3 years was greater after angioplasty, was equal between groups at 5 years.
The question is whether these results reflect symptom relief improvement over time among patients in the medical treatment group or symptom worsening among patients in the angioplasty group. The correct answer might be that symptom relief improved among patients in the medical treatment group due to a 51% crossover to angioplasty. This undoubtedly dilutes results and it is one of the disadvantages of the intention-to-treat analysis.
Data will be published soon using more sophisticated statistical methods in order to better differentiate both study arms.
Original title: Five-Year Outcomes with PCI Guided by Fractional Flow Reserve.
Reference: Xaplanteris P et al. N Engl J Med. 2018; Epub ahead of print.
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