Cardiogenic shock (CS), a severe manifestation of heart failure characterized by inadequate end-organ perfusion, is a critical condition with high mortality rates despite advancements in cardiovascular care.1 The pathophysiology of CS is complex, involving a downward spiral of decreasing cardiac output leading to further myocardial dysfunction.2 Temporary mechanical circulatory support (MCS) devices have emerged as vital tools in the management of CS, providing hemodynamic support to critically ill patients.3

The landscape of temporary MCS devices includes a variety of systems, such as the intra-aortic balloon pump (IABP), TandemHeart, Impella, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO).4 Each device has unique mechanisms of action and indications, with varying levels of support and risk profiles.5 The IABP is the most established MCS device, yet recent trials have questioned its effectiveness in improving outcomes in CS patients.6

Emerging devices like TandemHeart and Impella offer more substantial hemodynamic support by directly unloading the ventricles and improving cardiac output.7 However, their optimal use, including timing, patient selection, and duration of support, remains under investigation.8 VA-ECMO provides the highest level of circulatory support, crucial for patients with refractory CS, but it is associated with significant risks, including bleeding, limb ischemia, and neurological complications.9

Recent evidence suggests a paradigm shift toward early intervention with MCS in CS to prevent multi-organ failure and improve survival.10 The concept of ``door-to-support'' time is becoming increasingly recognized as critical in the management of CS, akin to ``door-to-balloon'' time in myocardial infarction.11 Despite these advances, the optimal choice of MCS device based on patient characteristics and clinical scenarios is not well-defined, leading to variability in clinical practice.12

Subgroup analysis in existing literature has begun to shed light on patient-specific factors that influence outcomes with MCS.13 For instance, the etiology of CS, such as acute myocardial infarction or non-ischemic cardiomyopathy, may impact the effectiveness and risk profile of MCS devices.14 Similarly, patient comorbidities like renal failure or pulmonary hypertension can influence device selection and anticipated benefit.15

Given the heterogeneity of CS and the expanding array of MCS options, a systematic review focusing on subgroup-specific effectiveness and safety is timely.16 Such an analysis can provide nuanced insights that guide clinicians in personalized decision-making, optimizing patient outcomes while minimizing risks.17 Moreover, identifying gaps in the current evidence can catalyze future research, enhancing our understanding and management of this critical condition.18

This review aims to dissect the current evidence on the comparative effectiveness and safety of temporary MCS devices in acute CS, with a focus on subgroup analyses that inform personalized clinical strategies.19 By elucidating these critical aspects, we aspire to contribute to the evolving narrative of tailored, evidence-based care in the realm of acute cardiogenic shock.20