Temporal cytokine trajectories during microaxial flow pump support identify a high-risk inflammatory phenotype in cardiogenic shock

Background Despite advances in temporary mechanical circulatory support, the mortality rate for patients with cardiogenic shock (CS) remains high. Current shock frameworks rely on hemodynamic parameters and fail to capture ongoing biological injury. Our study aimed to investigate cytokine trajectories during support and their association with clinical outcomes. Methods This single-center retrospective cohort study analyzed 113 patients with CS in SCAI stage ≥ C who were treated with microaxial flow pump (mAFP). Serial cytokine levels were measured from the time of mAFP implantation until day 7 afterwards. Time-point-specific multivariable logistic regression was used to identify independent predictors of 30-day mortality. The incremental prognostic value of cytokine levels was evaluated in relation to age, lactate, and vasoactive-inotropic score (VIS), with interaction analyses conducted in relation to hemodynamic severity and blood culture positivity. Results The overall 30-day mortality rate in the study cohort was 26.5%. IL-6 trajectories diverged progressively between survivors and non-survivors during mAFP support, with the greatest separation at 72 h. At this time point, log-transformed IL-6 was independently associated with 30-day mortality. ROC analysis at 72 h showed moderate discriminatory performance (AUC 0.745) and identified an optimal cut-off of 164.5 pg/mL (sensitivity 68.0%; specificity 82.1%). Patients with IL-6 levels ≥ 164.5 pg/mL presented with lower 30-day survival in exploratory landmark-type Kaplan–Meier analysis (log-rank p < 0.001). This association was not modified by blood culture positivity, although infection, culture-negative inflammatory complications, and vasoplegic/distributive physiology cannot be excluded as contributors to IL-6 elevation. Conclusions In patients with CS supported by mAFP, persistent IL-6 elevation at 72 h was associated with increased 30-day mortality and provided additional prognostic information alongside established clinical severity markers. These findings suggest that ongoing inflammatory activity may provide additional prognostic information and support further evaluation of serial IL-6 measurements for risk stratification.