Phenomapping-derived selection of fractional flow reserve or optical coherence tomography to personalise percutaneous coronary intervention

Introduction: An evidence-based selection between fractional flow reserve (FFR) and optical coherence tomography (OCT) to drive percutaneous coronary intervention is still lacking. Methods: Patients enrolled in the Fractional Flow Reserve vs. Optical Coherence Tomography to Guide Revascularization of Intermediate Coronary Stenoses (FORZA) trial and in the OCT-Features Of moRphology, coMposItion anD instABility of culprit and not culprit coronary pLaquE in ACS patient (OCT-FORMIDABLE) registry were included. Target vessel revascularisation (TVR) and major adverse cardiac events (MACE), a composite endpoint of cardiac death, myocardial infarction (MI) and TVR were considered as coprimary endpoints. Phenomapping with clustering was performed: incidence of outcomes according to FFR and OCT was explored. Results: 405 patients were treated according to OCT and 405 to FFR. Three different clusters were identified. 48% of the patients were included in the first cluster, presenting mainly with stable angina and a relevant burden of risk factors (cardiovascular risk factors, CVRFs). 21% of the patients were included in the second cluster, presenting with ST segment elevation MI (STEMI) and with low rates of CVRFs. 31% of the patients, being admitted mostly for non-STEMI (NSTEMI) and with high rates of CVRFs, were included in the third cluster. FFR and OCT performed similarly in terms of MACE and TVR in the first cluster. In the second cluster, rates of MACE were lower in the OCT arm (3% vs 12%, p 0.04), mainly driven by TVR (2% vs 6%, p 0.18). In the third cluster, rates of TVR were significantly reduced in the OCT arm (6% vs 14%, p 0.037) with a neutral impact on MACE (12% vs 15%, p 0.71). Conclusions: Compared with a functional assessment, an OCT-based approach reduces revascularisation in patients with STEMI/NSTEMI, while FFR proved non-inferior for patients with stable angina.