Primary PCI is still beneficial later than 24 hours after STEMI

Background: The impact of a mechanical reperfusion strategy beyond a 24-hour cut-off is still unsettled. Optimal management for these patients remains uncertain. Purpose: We sought to investigate the effect of delayed primary percutaneus coronary intervention (p-PCI) – 24 to 48 hours after symptom onset-for patients with ST-segment elevation myocardial infarction (STEMI) not undergoing timely reperfusion therapy. Methods: We conducted a cohort study of 1822 STEMI first-day survivors who were admitted with a diagnosis of STEMI, but did not receive any mechanical or pharmacological reperfusion therapy within 24 hours from symptom onset. We used multivariable logistic regression combined to landmark analysis to evaluate the effect of delayed p-PCI on in-hospital mortality and incidence of severe left ventricular dysfunction (LVD; ejection fraction<40%) at discharge. Patients who had routine medical treatment (RMT) and never received PCI served as controls. Data were adjusted for patient characteristics, concurrent medications and baseline risk status. Results: Patients undergoing delayed p-PCI had lower unadjusted in-hospital mortality (1.0% versus 6.2%, p<0.001) and incidence of severe LVD (19.6% versus 26.6%, p<0.05) than patients receiving RMT. Benefit of PCI remained significantly associated with mortality (OR: 0.32; 95% CI: 0.12–0.87) and LVD (OR:0.53; 95% CI: 0.33–0.87) after adjustment for baseline characteristics and concomitant medications. Benefit was greatest in the highest TIMI risk index patients where delayed p-PCI was associated with both a considerably lower risk of death (12.8% versus 2.5%; p<0.001) and a significant (p=0.04) reduction in the incidence of severe LVD (31.2% versus 23.1%). Conclusions: Patients not undergoing timely reperfusion therapy should be offered p-PCI on a liberal basis up to 48 hours from symptom onset.