Physiology-guided complete revascularization improves ¹-year outcomes compared with culprit-only revascularization in myocardial infarction (MI) patients aged ≥75 years, according to results from the FIRE trial presented during the ESC Congress 2023.^1,2 Principal investigator Dr. Simone Biscaglia from University Hospital of Ferrara, Italy highlighted the unique study population of this trial which focuses on older MI patients who are often underrepresented in clinical trials.^1,2 The FIRE trial thus sought to address the lack of robust evidence for an optimal revascularization strategy among patients in this age group which has posed a challenge in their clinical management.^2,3

“Whereas we know that complete revascularization has to be pursued in younger, 60-year-old patients, it is not clear if the same has to be done in older patients,” said Dr. Biscaglia.¹  This multicenter, prospective, randomized trial thus enrolled 1,445 patients from 34 sites in Italy, Spain and Poland, who were ≥75 years old and had been admitted to the hospital with either ST-segment elevation MI (STEMI) or non-ST-segment elevation MI (NSTEMI).^1,2 Those eligible for the trial were also required to have multivessel disease, consisting of ≥1 lesion in a non-culprit coronary artery with a minimum vessel diameter of 2.5mm and a visually estimated diameter stenosis of 50%-99%, as well as an apparent culprit lesion which had undergone successful percutaneous coronary intervention (PCI).^1,2 The median age of the study population was 80 years, which is approximately 20 years older than in earlier pivotal trials in the field, and 36.5% were women.^1,3

After successfully treating the culprit lesion, patients were randomized to receive either physiology-guided complete revascularization (n=720) or culprit-only revascularization (n=725).^1,2 In the physiology-guided complete revascularization group, patients underwent PCI of all functionally significant non-culprit lesions, which had been physiologically assessed using wire- and angiography-based measurements.^1,3 Conversely, patients assigned to culprit-only revascularization underwent no physiological assessment or revascularization of non-culprit lesions.¹

The study’s primary endpoint was a composite of death, MI, stroke or ischemia-driven coronary revascularization occurring within 1 year after randomization.^1,2 The key secondary endpoint was a composite of cardiovascular (CV) death or MI at 1 year.^1,2 The safety outcome was a one-year composite of contrast-associated acute kidney injury (CA-AKI), stroke or bleeding defined as type ³-5 according to the Bleeding Academic Research Consortium (BARC) classification.^1,2  A total of 1,444 patients (99.9%) completed 1 year of follow-up.^2,3

In the physiology-guided complete revascularization group, 113 patients (15.7%) experienced a primary outcome event, compared to 152 patients (21.0%) in the culprit-only group (HR=0.73; 95% CI: 0.57-0.93; p=0.01).^1,2 The number needed to treat (NNT) to prevent the occurrence of one primary outcome event was 19 patients.^1,2 Furthermore, the key secondary outcome of CV death or MI was also lower in the physiology-guided complete revascularization group (HR=0.64; 95% CI: 0.47-0.88; p=0.005) with an NNT of 22 patients.^1,2 Additionally, the incidence of individual components of the primary outcome appeared lower in the physiology-guided complete-revascularization group, except for stroke.2 There was also no significant difference in the composite safety outcome incidence between the 2 treatment groups (HR=1.11; 95% CI: 0.89-1.37; p=0.37).^1,2

Due to the higher risk for complications and coexisting illnesses in older patients with MI, elective invasive coronary procedures are performed less frequently.³ However, the results of this trial suggest that the benefits of physiology-guided complete revascularization among older patients are consistent with what has been observed in younger patients.³ These benefits are mainly driven by the reduction of MI recurrences and the need for repeated revascularization.³ One of the limitations of this trial is that results cannot be extrapolated to angiography-guided complete revascularization or to patients treated with other stent platforms.³

In summary, the results of the FIRE trial suggest that  physiology-guided complete revascularization in older MI patients with multivessel disease is a safe treatment strategy and even more effective in reducing death and MI than  culprit-only revascularization.¹