Association of inflammation with shock severity, 30-day mortality and therapy response in patients with cardiogenic shock

Abstract Background Elevated concentrations of C-reactive protein (CRP) and other circulating cytokines are often found in cardiogenic shock (CS). The role of systemic inflammation in the pathogenesis of cardiogenic shock remains unclear. To address this, associations between elevated plasma CRP concentrations upon admission with shock severity, 30-day mortality, and therapy response were analysed in patients with CS. Methods Plasma CRP concentrations were identified in a large data base containing unselected patients admitted with cardiogenic shock. The association between plasma CRP concentrations and CS severity (SCAI stage, reference SCAI B) was analyzed using adjusted linear and logistic regression models. The association between plasma CRP concentrations and 30-day mortality was analyzed using adjusted Cox regression models. The interaction between plasma CRP concentrations and treatment response was assessed by fitting an interaction term between plasma CRP concentrations and the use of mechanical circulatory support (MCS) in the above described Cox regression models. Results A total of 1116 patients were analysed. Median age was 70 years [interquartile range 58-78.6 years], 71.3% were male, 47.7% presented with CS due to acute myocardial infarction, and 58.3% with prior cardiac arrest. The median plasma CRP concentration was 17 mg/dl [interquartile range 5.0-71.0 mg/dl]. Plasma CRP concentrations were equally distributed among patients with higher vs. lower shock severity (higher SCAI stage). After adjustment for CS severity and other cofounders, higher plasma CRP concentrations were associated with higher 30-day mortality [8% relative risk increase per 50 mg/dl increase in plasma CRP, range 3-13%, adjusted p<0.001]. The association of plasma CRP concentration and 30-day mortality was abolished in patients treated with MCS [HR for CRP>median: MCS use 0.92 (95%-CI: 0.67-1.26; p=0.59)], while plasma CRP concentration was associated with 30-day mortality in patients not treated with MCS [HR for CRP>median 1.50 (95%-CI: 1.21-1.86; p<0.001); p-interaction=0.01]. Conclusion Increased concentrations of inflammatory cytokines are associated with a higher 30-day mortality regardless of shock severity. This association is abolished when mechanical circulatory support systems are used, potentially by providing sufficient end-organ perfusion. This interaction calls for further research on this topic.