Systolic Blood Pressure and Microaxial Flow Pump–Associated Survival in Infarct-Related Cardiogenic Shock

Importance: Microaxial flow pump treatment improves survival in selected patients with infarct-related cardiogenic shock; however, treatment carries substantial risks, and benefit may vary by patient subgroup. Systolic blood pressure (SBP) has been proposed as a modifier of the survival benefit. Objective: To investigate whether SBP at randomization modifies the survival benefit of microaxial flow pump treatment in ST-segment elevation myocardial infarction-related cardiogenic shock. Design, Setting, and Participants: This was a post hoc analysis of the Danish-German (DanGer) Shock open-label randomized clinical trial among adult patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock, conducted between 2013 and 2023 at 14 tertiary invasive cardiac centers in Denmark, Germany, and the United Kingdom. Data analysis was performed from January 7 to April 7, 2024. Intervention: Microaxial flow pump therapy plus standard care vs standard care alone. Main Outcomes and Measures: All-cause mortality at 180 days according to randomization SBP. Results: Of 355 patients included in the DanGer Shock trial, 351 patients had available SBP at randomization (median [IQR] age, 69 [59-76] years; 277 [79%] male). In a dichotomized regression analysis, microaxial flow pump treatment significantly reduced mortality for SBPs lower than 82 mm Hg compared with standard care alone (odds ratio [OR], 0.34; 95% CI, 0.18-0.63; P < .001). This was not evident for higher pressures (OR, 0.96; 95% CI, 0.53-1.70; P = .90; P for interaction = .02). Kaplan-Meier survival analysis and spline regression analysis supported these findings (P for interaction = .02; P for nonlinearity = .01). Conclusions and Relevance: Randomization SBP was associated with the survival benefit of microaxial flow pump treatment, with the most hypotensive patients deriving the largest survival benefit. Early SBP may help identify patients most likely to gain a net benefit from microaxial flow pump treatment. Findings are hypothesis generating. Trial Registration: ClinicalTrials.gov Identifier: NCT01633502.