Early support in patients with St-segment elevation myocardial infarction complicated by shock. Design of exception...

Cardiogenic shock (CS) is a state of critical end-organ hypoperfusion due to reduced cardiac output. Patients with acute myocardial infarction-related cardiogenic shock (AMI-CS) have a survival to discharge of only 50%-60%. Mechanical circulatory support (MCS) devices are intended to support the failing heart and improve perfusion. Randomized controlled trials are required to demonstrate the safety and effectiveness of MCS in AMI-CS, but patients with AMI-CS are often unable to provide informed consent for research. Multiple trials have enrolled patients with cardiac arrest using exception from informed consent (EFIC) for emergency research in the United States (U.S.) but none have enrolled patients with AMI-CS using the same mechanism. To address discordant estimates of the effectiveness of MCS in patients with AMI-CS, a multicenter randomized trial was initiated in the U.S. and Europe to assess the effectiveness of early use of microaxial flow pumps [MFP] (Impella, J + J Heart Recovery Inc., Danvers, MA). A central Institutional Review Board (CIRB) approved the protocol with a tiered consent process and EFIC procedures in anticipation that some patients or their legally authorized representative would be able to provide prospective consent while many would not. Standardized community consultation and public disclosure activities were developed and implemented centrally by an Emergency Care Core ECC) in collaboration with the steering committee, sponsor and candidate sites. We herein describe the EFIC process and methods that were used to implement an AMI-CS trial in the U.S.