Could emulated trials play a key role in cardiogenic shock trials?

Temporary mechanical circulatory support (tMCS) using extracorporeal life support (ECLS), has been widely implemented in patients with cardiogenic shock (CS), although evidence regarding its efficacy and safety remains unclear. This lack of clarity has recently raised concerns about the role of tMCS in CS management. Conducting randomized controlled trials (RCTs) in the context of CS poses significant challenges due to ethical considerations and logistical complexities. In response to these challenges, emulated trials (ETs) are emerging as a promising alternative. By incorporating design features from idealized RCTs, they use robust and rigorous methods to assess the efficacy and safety of health interventions in real-life settings, using observational data. In our manuscript, we highlight the complementary nature of RCT and ETs by evaluating tMCS for CS patients. While RCTs follow a rigorous experimental design and provide reliable evidence, ETs can swiftly estimate the risk-benefit ratio without encountering logistical barriers thereby offering clinicians’ early reassurance about the potential benefits of routinely used interventions. Furthermore, ETs offer potential value in unethical situations (refractory cardiac arrest or "crash and burn" CS) where interventional therapies, such as tMCS, are used as a last resort.