Post Felix, Weilemann Ludwig S, Messow Claudia-Martina, Sinning Christoph, Münzel Thomas
Department of Medicine II, Johannes Gutenberg-University of Mainz, Germany.
Crit Care Med. 2008 Nov;36(11):3030-7. doi: 10.1097/CCM.0b013e31818b9153.
In early stages of septic shock, impaired myocardial function plays an important prognostic role. In this context, B-type natriuretic peptide (BNP) has been shown to be a neurohumoral marker for left ventricular dysfunction, because myocardial strain and ischemia both increase BNP concentration. The present study was designed to test if BNP allows for identification of patients at risk for developing sepsis-induced myocardial depression and if an increased concentration of BNP is associated with an adverse outcome in patients with septic shock.
In a prospective study, 93 patients with septic shock were divided into one group with normal ventricular function (left ventricular ejection fraction >50%) on days 3 to 5 (n = 38) and another group of patients with impaired left ventricular function (left ventricular ejection fraction <50%) on days 3 to 5 (n = 55). Patients with impaired left ventricular function had an increased median plasma BNP concentration on day 5 (699 [608 of 795.5] pg/nL vs. 86 [71.3 of 93] pg/nL) and an ejection fraction of 38 +/- 6% on day 5 vs. 58 +/- 7% in patients without impaired left ventricular function. There was a close inverse relation between increased plasma BNP concentrations and depressed left ventricular ejection fraction (p < 0.05). BNP measured at days 3 and 5 revealed an association with the end point of survival. In the proportional hazards regression model adjusted for age, male gender, and creatinine concentration, measured at days 0, 3, 5, and 12, BNP concentration at day 5 showed an increased hazard for reaching the end point (hazard ratio: 1.407; 95% confidence interval: 1.033-1.916; p = 0.030). In an additional receiver operating characteristic curve analysis, the predictive value of a model including cardiovascular risk factors and additional BNP concentration on day 5, compared with a baseline model of cardiovascular risk factors, improved the area under the curve the most; therefore, this model was suited best for prediction of sepsis-induced myocardial depression and 30-day survival for patients with septic shock. Area under the curve of this model combined with BNP concentration at day 5 for death after 30 days (0.65) impaired left ventricular ejection fraction (0.94) and sepsis-induced myocardial depression (0.96).
These results indicate that plasma BNP concentration represents a reliable marker for identification of patients developing sepsis-induced myocardial depression. In addition, BNP concentration on day 5 may be used as a prognostic marker to identify patients with an elevated risk for an adverse outcome.
在感染性休克的早期阶段，心肌功能受损起着重要的预后作用。在这种情况下，B型利钠肽（BNP）已被证明是左心室功能障碍的神经体液标志物，因为心肌应变和缺血都会增加BNP浓度。本研究旨在测试BNP是否能够识别有发生脓毒症诱导的心肌抑制风险的患者，以及BNP浓度升高是否与感染性休克患者的不良结局相关。
在一项前瞻性研究中，93例感染性休克患者在第3至5天被分为一组左心室功能正常（左心室射血分数>50%）的患者（n = 38）和另一组左心室功能受损（左心室射血分数<50%）的患者（n = 55）。左心室功能受损的患者在第5天的血浆BNP浓度中位数升高（699[608至795.5]pg/nL对86[71.3至93]pg/nL），第5天的射血分数为38±6%，而左心室功能未受损的患者为58±7%。血浆BNP浓度升高与左心室射血分数降低之间存在密切的负相关（p<0.05）。在第3天和第5天测量的BNP显示与生存终点相关。在根据年龄、男性性别和肌酐浓度调整的比例风险回归模型中，在第0、3、5和12天测量，第5天的BNP浓度显示达到终点的风险增加（风险比：1.407；95%置信区间：1.033 - 1.916；p = 0.030）。在额外的受试者工作特征曲线分析中，与心血管危险因素的基线模型相比，包含心血管危险因素和第5天额外BNP浓度的模型的预测价值使曲线下面积改善最大；因此，该模型最适合预测感染性休克患者的脓毒症诱导的心肌抑制和30天生存率。该模型结合第5天的BNP浓度用于30天后死亡（曲线下面积0.65）、左心室射血分数受损（曲线下面积0.94）和脓毒症诱导的心肌抑制（曲线下面积0.96）。
这些结果表明，血浆BNP浓度是识别发生脓毒症诱导的心肌抑制患者的可靠标志物。此外，第5天的BNP浓度可作为预后标志物，用于识别不良结局风险升高的患者。
