Plasma concentrations of interleukin-6, organ failure, vasopressor support, and successful coronary revascularization in predicting 30-day mortality of patients with cardiogenic shock complicating acute myocardial infarction.

OBJECTIVE: Inflammation may play an important role in the pathogenesis, persistence, and prognosis of cardiogenic shock. We analyzed whether elevated plasma concentrations of inflammatory markers are independently associated with an adverse prognosis (increased 30-day mortality rate) in patients with cardiogenic shock.

DESIGN: Retrospective study.

SETTING: Single-center study, eight-bed intensive care unit at a university hospital.

PATIENTS: Retrospective study on stored plasma samples from 38 patients with cardiogenic shock complicating acute myocardial infarction.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Thirty-day nonsurvivors (n = 23, 61%) had been less frequently successfully revascularized, exhibited more frequently renal failure, needed higher vasopressor doses, and presented with significantly higher interleukin-6 plasma concentrations on intensive care unit admission than 30-day survivors. Univariate hazard ratios (95% confidence interval) for 30-day mortality were 1.49 (1.24-1.80) for every 50 pg/mL increase in the interleukin-6 plasma concentration (p = .00003), 1.06 (1.02-1.10) for every 0.1 microg x kg x min increase in the total vasopressor dose (p = .007), 1.14 (1.04-1.25) for every mmol/L increase in serum lactate (p = .006), 2.47 (1.06-5.73) for acute renal failure (p = .036), and 0.34 (0.14-0.82) for successful revascularization (p = .016). However, interleukin-6 plasma concentrations were correlated with vasopressor need and were significantly higher in patients with acute renal failure and in patients without or unsuccessful revascularization. In a multivariate Cox-proportional hazard model, interleukin-6 was the only significant predictor of 30-day mortality with a hazard ratio of 1.42 (1.12-1.80, p = .004). Accordingly, interleukin-6 concentrations > or =200 pg/mL (the point of maximum interest by receiver operating characteristic analysis with a specificity of 87% and a sensitivity of 74%) were associated with a significantly increased 30-day mortality rate in both patients with and patients without successful revascularization.

CONCLUSIONS: Interleukin-6 concentrations are an independent predictor of 30-day mortality in patients with acute myocardial infarction complicated by cardiogenic shock.