Predictors of Reperfusion Delay in Patients With Acute Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention from the HORIZONS-AMI Trial

Primary percutaneous coronary intervention (PCI) is the optimal method of reperfusion when performed expeditiously. Factors contributing to delays in PCI for ST-segment elevation myocardial infarction (STEMI) have not been thoroughly characterized or quantified. We sought to identify the factors associated with the delays to reperfusion in patients with STEMI undergoing primary PCI. Primary PCI was performed in 3,340 patients with STEMI in the international, multicenter Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial. Multivariate analysis was used to identify independent predictors of delay in achieving reperfusion from 38 baseline and procedural variables. A total of 905 patients (27.1%) presented to non-PCI hospitals and were subsequently transferred; the remainder presented to PCI hospitals. The most powerful independent predictor of the interval from symptom onset to arrival at the PCI hospital and the first door-to-balloon time was an initial presentation at a non-PCI hospital (median incremental 58- and 54-minute delay, respectively, both p <0.001). Other independent predictors of prolonged door-to-balloon times included presentation with respiratory failure (42-minute incremental delay, p = 0.003), presentation during off-work hours (11-minute incremental delay, p <0.001), and co-morbid conditions such as diabetes and heart failure. In conclusion, among patients undergoing primary PCI, presentation to a non-PCI hospital was the variable associated with the greatest delay to reperfusion. Systems of care that encourage ambulance diagnosis and direct delivery of patients with STEMI to a PCI hospital might shorten the overall door-to-balloon times and improve the clinical outcomes.