Outcomes according to timely or delayed primary percutaneous coronary intervention or fibrinolysis in a national registry of patients with ST-segment elevation myocardial infarction

Background: Time to reperfusion is a predictor of long-term outcomes in ST-segment elevation myocardial infarction (STEMI). Timely primary percutaneous coronary intervention (PCI) is the preferred strategy recommended by guidelines. Fibrinolysis is recommended in patients in whom timely primary PCI is not feasible, though concerns persist about underutilisation of this approach. We examined long-term survival outcomes in STEMI patients according to treatment strategy received in a national STEMI registry in Ireland. Methods: This was an observational, nationwide, population-based study. We identified all STEMI cases from January 2013 to March 2018. After exclusion of patients with missing data, we divided patients into three groups as per reperfusion strategy—fibrinolysis, delayed primary PCI (>120 min of diagnosis) and timely primary PCI (<120 min of diagnosis)—and analysed mortality through to 3 years follow-up. A multivariate Cox proportional hazards model was used, with a propensity score matching analysis performed as a sensitivity analysis. Results: Of the 4156 patients included in this analysis, 202 (4.9%) were treated with fibrinolysis, 1075 (25.8%) were treated with delayed primary PCI and 2879 (69.3%) were treated with timely primary PCI. At follow-up, delayed primary PCI was associated with an increased risk of mortality through to 3 years in comparison to fibrinolysis (HR_adjusted, 1.36; 95% CI 1.02 to 1.83, p=0.04). Timely primary PCI was associated with a comparable risk of mortality through to 3 years in comparison to fibrinolysis (HR_adjusted, 1.10; 95% CI 0.81 to 1.49, p=0.53). Conclusions: A sizeable proportion of STEMI patients continue to receive treatment with delayed primary PCI. This is associated with an increased risk of mortality through 3 years in comparison to fibrinolysis.