Long-term clinical outcomes of high-risk plaques with negative fractional flow reserve: the PECTUS-obs study

BACKGROUND: High-risk plaques (HRP) in non-flow-limiting, deferred non-culprit lesions have been associated with adverse short-term cardiovascular outcomes after myocardial infarction (MI). However, the long-term prognostic implications remain largely unknown. AIMS: This study sought to evaluate the long-term association between HRP and clinical outcome after MI Methods: In the prospective, observational PECTUS-obs study, 438 patients with recent MI underwent optical coherence tomography (OCT) of all fractional flow reserve-negative non-culprit lesions. Patients were grouped according to the presence or absence of at least one OCT-identified HRP. The current study evaluates the final long-term outcome. The primary patient-level endpoint was defined as major adverse cardiovascular events (MACE), a composite of cardiac death, non-fatal MI, or unplanned revascularisation, excluding all periprocedural, indeterminate, and stent failure-related events. RESULTS: After a median follow-up of 1,828 days (interquartile range [IQR] 1,821-1,842), the presence of at least one HRP was associated with MACE (hazard ratio [HR] 1.87, 95% confidence interval [CI]: 1.11-3.14; p=0.017). Among the individual endpoint components, non-fatal MI (HR 4.07, 95% CI: 1.23-13.52; p=0.013) and unplanned revascularisation (HR 1.97, 95% CI: 1.07-3.64; p=0.027) occurred more frequently in patients with at least one HRP. In an exploratory landmark analysis, the risk associated with presence of HRP was observed only during the first 2 years of follow-up. The lesion-level incidence of target lesion failure did not differ significantly between groups (HR 1.65, 95% CI: 0.91-2.96; p=0.097). CONCLUSIONS: Non-flow-limiting, high-risk non-culprit plaques are associated with adverse patient-level clinical outcomes during long-term follow-up after MI, potentially with a more pronounced short-term risk. CLINICALTRIALS: gov: NCT03857971.