Inflammatory response by 48 h after admission and mortality in patients with acute myocardial infarction complicated by cardiogenic shock

Aims Cardiogenic shock (CS) is known to induce an inflammatory response. The prognostic utility of this remains unclear. To investigate the association between C-reactive protein (CRP) levels and leucocyte count and mortality in patients with acute myocardial infarction complicated by CS (AMICS). Methods and results Consecutive patients (N = 1716) admitted between 2010 and 2017 with an individually validated diagnosis of AMICS were included. The analysis was restricted to patients alive at 48 h after first medical contact and a valid CRP and leucocyte measurement at 48 ± 12 h from the first medical contact. A combined inflammatory score for each patient was computed by summing the CRP and leucocyte count z-scores to normalize the response on a standard deviation scale. Associations with mortality were analysed using a multivariable Cox proportional hazards model stratified by inflammatory response quartiles: Of the 1716 patients in the cohort, 1111 (64.7%) fulfilled inclusion criteria. The median CRP level at 48 h was 145 mg/dL [interquartile range (IQR) 96–211]. The median leucocyte count was 12.6 × 10/L (IQR 10.1–16.4). Patients with the highest inflammatory response (Q4) had lower median left ventricular ejection fractions and higher lactate levels at the time of diagnosis. The 30-day all-cause mortality rates were 46% in Q4 and 21% in Q1 (P < 0.001). In multivariable models, the inflammatory response remained associated with mortality [hazard ratio (HR) 2.32, 95% confidence interval (CI) 1.59–3.39, P < 0.001]. The finding was also significant in AMICS patients presenting with out-of-hospital cardiac arrest following multivariable adjustment (HR 3.37, 95% CI 2.02–4.64, P < 0.001). Conclusion Cardiogenic shock induces an acute inflammatory response, the severity of which is associated with mortality.