A Framework for Exception From Informed Consent in Trials Enrolling Patients With ST-Segment-Elevation Myocardial Infarction and Cardiogenic Shock.

Cardiogenic shock (CS) is critical end-organ hypoperfusion attributable to reduced cardiac output. Acute ST-segment-elevation myocardial infarction with CS (AMI-CS) has high mortality. Clinical research is challenging in such patients as they often cannot provide consent, lack available legal representatives, and require initiation of therapy. Multiple trials have enrolled patients with AMI-CS outside the United States under deferred consent. Trials in the United States have enrolled patients with out-of-hospital cardiac arrest under exception from informed consent (EFIC). However, AMI-CS has a longer therapeutic window to initiate treatment than out-of-hospital cardiac arrest, and more patients or their representatives can engage in treatment decisions. We provide a rationale for how a trial enrolling patients with AMI-CS could qualify for conduct using EFIC by meeting each criterion specified in US human subject regulations. AMI-CS is a life-threatening situation, available treatments are unsatisfactory, and collection of valid evidence is necessary. Obtaining informed consent is often not feasible, and trial participation could benefit subjects. Only enrolling consented patients is impracticable and could reduce the study's generalizability. We propose a therapeutic window of 30 minutes within the study intervention must be initiated, with consent sought within 15 minutes, respecting any refusal or objection to enrollment, and otherwise enrollment under EFIC. A trial could enroll patients with AMI-CS under EFIC and can involve both patients and their representatives. Successful use of EFIC in trials of other interventions in patients with CS or enrolling patients with other acute cardiovascular conditions could increase the available evidence base to improve care.