The impact of processes of care on myocardial infarct size in patients with ST-segment elevation myocardial infarction: Observations from the CRISPAMI trial

Background: Primary percutaneous coronary intervention (PCI) is the most common method of reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) in the United States. The intersection between processes of care and performance measures such as door-to-balloon (D2B) times and clinical trials evaluating novel therapies for STEMI has not been fully investigated. Hypothesis: Processes of STEMI care, incorporating clinical trial enrollment and randomization, in patients undergoing reperfusion with primary PCI in the Counterpulsation Reduces Infarct Size Pre-Percutaneous Coronary Intervention Acute Myocardial Infarction trial (CRISP-AMI) will conform to current standards of care. Methods: Patients enrolled in CRISP-AMI were included in the current analysis. Processes of care during reperfusion were recorded prospectively and compared between groups. Results: A total of 337 patients with anterior STEMI without cardiogenic shock were randomized in CRISP-AMI. Complete processes-of-care data were available for 303 patients (89.9%). In this cohort, 68.0% of patients underwent reperfusion within 90 minutes of hospital contact, and the median D2B time was 71 minutes. Time from hospital contact to informed consent was significantly different across different regions (North America, 45 minutes; India, 35 minutes; Europe, 20 minutes). Conclusions: In CRISP-AMI, reperfusion was accomplished in a timely fashion while incorporating informed consent and randomization among patients with anterior myocardial infarction. Further study of patients' comprehension and preferences during the informed-consent process in STEMI patients is warranted so that innovative drugs and devices can be safely and ethically tested.