Background: Since 2006 the Center for Medicare and Medicaid Services has allowed hospitals to exclude public reporting of door to balloon (D2B) time data for STEMI patients with cardiopulmonary arrest (CPA) within 90 minutes after hospital arrival, a high risk group with 30% in-hospital mortality. In July 2014, we implemented a high reliability STEMI process with rapid reperfusion goals for all STEMI patients treated with primary PCI at our center with no patient exclusions (figure). We studied D2B times for patients with and without in-hospital CPA before and after implementation of our high reliability STEMI process to clarify whether exclusion from public reporting on the basis of CPA is justified. Methods: We compared consecutive cases of STEMI treated with primary PCI at our center before (January 2013 to July 15 th , 2014) and after (July 16 th , 2014 to October 2016) implementation of a high reliability STEMI process, and we assessed D2B times in patients with and without in-hospital CPA prior to primary PCI. The primary endpoint was the % of patients treated within guideline D2B times ( < 90 minutes for ED presenting patients or < 120 minutes for inter-hospital transfer patients). Results: Over the study period 795 cases of STEMI were treated with primary PCI at our center. The control group constituted 37.4% (297/795) of patients who were treated prior to July 15 th , 2014, and the high reliability group constituted 62.6% (498/795) of patients treated after July 15 th , 2014. Patients presenting to our primary ED were 27.3% (217/795), inter-hospital transfer patients were 69.1% (549/795), and in-hospital STEMI patients were 3.6% (29/795). CPA within 90 minutes of hospital arrival occurred in 6.3% (50/795) of patients overall, and CPA was more prevalent in the control group vs the high reliability group (8.8% [26/297] vs 4.8% [24/498], P=0.027). In the control group patients with CPA were less likely to achieve goal D2B times compared to patients without CPA (30.8% [8/26] vs 60.5% [164/271], P=0.003), whereas in the high reliability group there was no difference in the rate of achievement of goal D2B times in patients with vs without CPA (75.0% [18/24] vs 81.6% [387/474], P=0.418). Conclusion: High reliability STEMI processes can improve delivery of care for the most vulnerable and highest risk patients.