Abstract Body (Do not enter title and authors here): Background: A systemic inflammatory response is common in patients with cardiogenic shock (CS) and associated with more severe disease and increased mortality. C-reactive protein (CRP) is a widely accessible and cost-effective biomarker of inflammation that may aid in prognostication in patients with CS.

Research Questions: The aim of this study was to evaluate the association between admission CRP and in-hospital mortality in patients with CS.

Methods: Using the Vizient® Clinical Data Base, we identified adults ≥18 years admitted with CS from October 1, 2015, to June 30, 2023. We identified patients with a CRP value on the first two days of admission. Patients with sepsis on admission were excluded. Cohorts were analyzed in CRP tertiles. Using inverse probability treatment weighting (IPTW), adjusting for demographics, comorbidities, labs (initial lactate and white blood cell count), and vasoactive and mechanical circulatory support (MCS) on the first day of admission, we assessed for the association between admission CRP and in-hospital mortality.

Results: We identified 28,806 patients with an available CRP on the first two days of admission, including 18,749 on day 1 and 10,057 on day 2. The average age was 62.8 years (±15.9), 62.7% (n=18,058) were men, 20.9% required MCS, and the median (IQR) CRP was 11.1 mg/dL (3.0-43.1 mg/dL). The unadjusted in-hospital mortality was 29.0%, 37.4%, and 41.3% for tertiles 1, 2, and 3, respectively. The odds of in-hospital mortality increased by 17% for each 50-unit increase in admission CRP (OR 1.17; 95% CI: 1.15-1.19, p<0.001) (Figure). After IPTW, compared to patients in the first CRP tertile, tertiles 2 and 3 were associated with an increased weighted mean mortality of 6.7% (95% CI: 5.1% to 8.4%) and 10.3% (95% CI: 8.6% to 12.0%), respectively (both, p<0.001). Similar trends were observed when including only those with a CRP obtained on day 1, when limited to a primary admission diagnosis of heart failure or acute myocardial infarction, and amongst patients requiring MCS within the first 2 days (all, p<0.05).

Conclusion(s): In patients with CS, the readily available biomarker, CRP, was associated with higher in-hospital mortality. Future studies are needed to assess the prospective impact of CRP, potentially utilized within shock stages or in isolation, on clinical outcomes for patients with CS.