Kinetics of procalcitonin, C-reactive protein and interleukin-6 in cardiogenic shock - Insights from the CardShock study.

BACKGROUND

Inflammatory responses play an important role in the pathophysiology of cardiogenic shock (CS). The aim of this study was to investigate the kinetics of procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6) in CS and to assess their relation to clinical presentation, other biochemical variables, and prognosis.

METHODS

Levels of PCT, CRP and IL-6 were analyzed in serial plasma samples (0-120h) from 183 patients in the CardShock study. The study population was dichotomized by PCTmax ≥ and < 0.5 μg/L, and IL-6 and CRPmax above/below median.

RESULTS

PCT peaked already at 24 h [median PCTmax 0.71 μg/L (IQR 0.24-3.4)], whereas CRP peaked later between 48 and 72 h [median CRPmax 137 mg/L (59-247)]. PCT levels were significantly higher among non-survivors compared with survivors from 12 h on, as were CRP levels from 24 h on (p < 0.001). PCTmax ≥ 0.5 μg/L (60% of patients) was associated with clinical signs of systemic hypoperfusion, cardiac and renal dysfunction, acidosis, and higher levels of blood lactate, IL-6, growth-differentiation factor 15 (GDF-15), and CRPmax. Similarly, IL-6 > median was associated with clinical signs and biochemical findings of systemic hypoperfusion. PCTmax ≥ 0.5 μg/L and IL-6 > median were associated with increased 90-day mortality (50% vs. 30% and 57% vs. 22%, respectively; p < 0.01 for both), while CRPmax showed no prognostic significance. The association of inflammatory markers with clinical infections was modest.

CONCLUSIONS

Inflammatory markers are highly related to signs of systemic hypoperfusion in CS. Moreover, high PCT and IL-6 levels are associated with poor prognosis.