Time-dependent survival benefit of late PCI in stable STEMI: a propensity-weighted analysis of the 12–48 hour window

Background Data supporting percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) beyond the 12-hour cut-off are sparse and contradictory. Current guidelines provide inconsistent recommendations for stable late-presenters, representing a critical evidence gap for clinicians and policymakers, particularly in regions with delayed access to care. Purpose The study aimed to evaluate the effects of delay to hospital presentation on 30-day mortality following PCI versus routine medical treatment (RMT) in stable STEMI patients presenting 12 to 48 hours after symptom onset. Methods We identified 2,730 clinically stable patients with STEMI presenting 12 to 48 hours after symptom onset from the ISACS registry. The effects of PCI versus routine medical treatment (RMT) were assessed. Patients with cardiogenic shock, cardiac arrest, severe heart failure, persistent angina, or early revascularization were excluded. The primary endpoint was 30-day mortality. Inverse probability of treatment weighting (IPTW) based on propensity scores was applied to adjust for baseline differences, and interaction testing was performed to evaluate effect modification by time of presentation. Results PCI was associated with lower 30-day mortality compared with RMT (3.1 % versus 5.5%; OR, 0.54; 95% CI, 0.36 to 0.84) in the overall cohort. Yet, delay to hospital presentation influenced treatment outcomes (Pinteraction =0.001). Risk-adjusted 30-day mortality rate after PCI was higher in patients who underwent PCI between 12 to 24 hours (6.3%) compared with that of patients who underwent PCI between 25 to 48 hours (1.8%). PCI was associated with better survival compared with RMT only in patients undergoing PCI between 25 and 48 hours after symptom onset (OR: 0.30; 95%CI: 0.16–0.58; P <0.001). Propensity score matching gave similar results. Conclusions In clinically stable STEMI patients presenting 12–48 hours after symptom onset, the benefit of PCI is highly time-dependent and suggests a "tailored" rather than "universal" approach. The survival advantage is specifically concentrated in the 25–48 hour window, challenging the assumption that earlier intervention is always superior and supporting a more tailored, time- and symptom-sensitive approach. Selective revascularization may improve outcomes without exposing all late presenters to unnecessary intervention.