Generalizability of Landmark Temporary MCS Device Trials

BACKGROUND: Landmark randomized controlled trials like DanGer Shock, IABP-SHOCK II, and ECLS-SHOCK guide infarct-related cardiogenic shock (CS) management with temporary mechanical circulatory support (tMCS), but strict enrollment criteria may limit real-world applicability. OBJECTIVES: The objective of the study was to evaluate the eligibility overlap of patients from these three key CS trials with the contemporary CS Working Group registry. METHODS: In this retrospective analysis, CS patients enrolled between 2020 and 2024 in the CS Working Group registry were assessed. Using trial-specific enrollment criteria (DanGer Shock, IABP-SHOCK II, and ECLS-SHOCK), subsets of patients meeting these criteria were identified. We compared baseline characteristics and usage patterns of tMCS devices among trial-eligible and trial-ineligible patients. RESULTS: Only a small proportion of registry patients met all the key enrollment criteria: 19.3% (DanGer Shock), 28.4% (IABP-SHOCK II), and 23.6% (ECLS-SHOCK). Hypotension and elevated lactate thresholds were the most restrictive criteria across trials. Trial-eligible patients had more severe CS and end-organ damage than ineligible patients. Actual device use in real-world practice differed markedly from trial assignments; notably, only 20% of DanGer-like patients received Impella CP as their first device. CONCLUSIONS: Patients meeting the landmark CS trial criteria represent a small, high-risk subset of the real-world CS population, highlighting a substantial evidence gap for the majority of CS patients receiving tMCS in clinical practice. Enhancing registry enrollment of specific CS subsets and adopting innovative analytic strategies could bridge gaps between randomized controlled trials findings and real-world applicability.