At the outer edge of STEMI time: even after 12 hours, the clock keeps ticking

Abstract Introduction Although primary percutaneous coronary intervention (pPCI) is not a class I recommendation in all patients (pts) presenting within 12 to 48h of symptom onset (late ST-segment Elevation Myocardial Infarction, STEMI), there is increasing evidence supporting its routine use in this population. Data on long-term clinical outcomes is sparse. Objective To evaluate long-term MACE in late-STEMI pts submitted to pPCI and compare with clinical outcomes of early reperfusion groups. Methods Retrospective analysis of consecutive pts submitted to pPCI due to STEMI between 2010 and 2015 in a pPCI centre. Included pts were stratified in 5 groups according to symptom-to-balloon time (SBT): <3h; 3–6h; 6–12h; 12–24h; 24–48h. Of a total of 903 pts, 19 pts were excluded due to SBT >48h. Long-term events were established as 5y mortality and 5y-MACE (a composite endpoint of death, re-infarction, heart failure hospital admission and ischemic stroke). The cumulative incidence of long-term outcomes was calculated by the Cox regression analysis and presented according to the Kaplan-Meier method. Results Of the 884 pts included in the study, stratification according to SBT was: pPCI<3h (47.4%), pPCI 3–6h (24.9%), pPCI 6–12h (16.5%), pPCI 12–24h (8.0%), and pPCI 24–48h (3.2%). These groups showed no significant difference in terms of demographic characteristics (age, CV risk factors, previous coronary disease or heart failure), clinical severity (systolic arterial pressure, Killip-Kimball class, left ventricle ejection fraction) and angiography findings (multivessel disease, complete revascularization and PCI success). After a median follow-up of 76 (56; 98) months, 5-year mortality was 20.6% (182 pts) and 5-year MACE was 23.3% (206 pts). MACE was associated with increased median SBT: 5.0 (2.0; 9.0) hours vs 4.0 (2.0; 6.5) hours, p<0.001. Of the MACE components, the only that showed a significant association with higher median SBT was mortality: 5.0 (2.0; 10.0) hours vs 4.0 (2.0; 6.0), p<0.001. Differences in long-term outcomes were significant when considering SBT stratified by revascularization time (Figure 1). Conclusions As expected, there is a clinical benefit of early reperfusion for long-term cardiovascular events. Within the late-STEMI group, there seems to be a clear distinction between pPCI<24h and >24h, although the clinical benefit of pPCI timing most probably acts a continuum. Funding Acknowledgement Type of funding sources: None.