Sommerer C, Heckele S, Schwenger V, Katus H A, Giannitsis E, Zeier M
Department of Nephrology, University Department of Cardiology, University Hospital of Heidelberg, Germany.
Clin Nephrol. 2007 Dec;68(6):392-400. doi: 10.5414/cnp68392.
The cardiac biomarkers cardiac Troponin T (cTNT) and NT-proBNP tend to be elevated in nearly all hemodialysis patients. The high percentage and magnitude of these increased molecules is associated with cardiovascular morbidity and mortality in hemodialysis patients. This study investigates the impact of the dialysis procedure itself on cardiac biomarkers.
Standard chronic hemodialysis lasting 4-5 hs 3 times weekly and using polysulfone dialyzers (high-flux and low-flux) was performed. Blood flow rates varied between 250-350 ml/min. The cTNT levels of 49 chronic hemodialysis patients were measured twice (interval of 6 weeks) before and after a hemodialysis session by a third-generation assay (Elecsys Analyzer, Roche Diagnostics, Mannheim, Germany). NT-proBNP levels were measured with polyclonal antibodies capable of recognizing the N-terminal fragment of BNP. In a follow-up period of 42 months, cardiovascular events and death were assessed.
The median concentration of cTNT prior to hemodialysis was 0.024 ng/ml (< 0.001-0.703). All dialysis patients presented high plasma levels of NT-proBNP (median 4,885 pg/ml). Oligoanuric patients had significantly higher cTNT and NT-proBNP levels prior to dialysis compared to patients with normal diuresis (p < 0.0001). cTNT and NT-proBNP levels increased significantly during the hemodialysis sessions in which a low-flux dialyzer was used (p < 0.0001) but remained unchanged when a high-flux dialyzer was utilized. Neither the predialytic nor the interdialytic changes in cTNT and NT-proBNP levels were influenced by blood flow. NT-proBNP levels increased markedly during hemodialysis sessions (p < 0.005) utilizing the low-flux dialyzer. Patients with a non-native fistula had significantly higher predialysis cTNT and NT-proBNP levels (p < 0.05). Patients with cardiovascular events had a significantly higher cTNT and NT-proBNP at the beginning of the study.
Asymptomatic chronic hemodialysis patients have significantly higher levels of the cardiac biomarkers cTNT and NT-proBNP relative to the general population. The levels are associated with the time of measurement (before and after a hemodialysis session). Dialysis modalities like high-flux dialyzers influence cTNT and NT-proBNP levels and should be taken into account, particularly in patients with acute onset of cardiac ischemia. The elevation of cTNT and NT-proBNP levels after hemodialysis using a low-flux dialyzer are partly due to hemoconcentration. The significant association of cTNT and NT-proBNP with non-native fistulas (catheter or graft) may be due to the chronic inflammation commonly caused by these devices. Both cardiac biomarkers are of prognostic value determining cardiovascular events and death.
几乎所有血液透析患者的心脏生物标志物心肌肌钙蛋白T（cTNT）和N末端脑钠肽原（NT-proBNP）往往都会升高。这些升高分子的高比例和高幅度与血液透析患者的心血管发病率和死亡率相关。本研究调查了透析过程本身对心脏生物标志物的影响。
进行标准的慢性血液透析，每周3次，每次持续4 - 5小时，使用聚砜透析器（高通量和低通量）。血流速度在250 - 350毫升/分钟之间变化。通过第三代检测方法（Elecsys分析仪，罗氏诊断公司，德国曼海姆）在49例慢性血液透析患者进行血液透析前后（间隔6周）各测量一次cTNT水平。使用能够识别BNP N末端片段的多克隆抗体测量NT-proBNP水平。在42个月的随访期内，评估心血管事件和死亡情况。
血液透析前cTNT的中位浓度为0.024纳克/毫升（<0.001 - 0.703）。所有透析患者的NT-proBNP血浆水平都很高（中位值4885皮克/毫升）。与利尿正常的患者相比，少尿无尿患者透析前的cTNT和NT-proBNP水平显著更高（p<0.0001）。在使用低通量透析器的血液透析过程中，cTNT和NT-proBNP水平显著升高（p<0.0001），但使用高通量透析器时则保持不变。cTNT和NT-proBNP水平的透析前及透析间期变化均不受血流影响。在使用低通量透析器的血液透析过程中，NT-proBNP水平显著升高（p<0.005）。使用非自体动静脉内瘘的患者透析前的cTNT和NT-proBNP水平显著更高（p<0.05）。发生心血管事件的患者在研究开始时的cTNT和NT-proBNP水平显著更高。
无症状慢性血液透析患者的心脏生物标志物cTNT和NT-proBNP水平相对于普通人群显著更高。这些水平与测量时间（血液透析前后）相关。高通量透析器等透析方式会影响cTNT和NT-proBNP水平，应予以考虑，尤其是在急性心肌缺血发作的患者中。使用低通量透析器进行血液透析后cTNT和NT-proBNP水平升高部分归因于血液浓缩。cTNT和NT-proBNP与非自体动静脉内瘘（导管或移植物）的显著关联可能是由于这些装置通常引起的慢性炎症。这两种心脏生物标志物对于确定心血管事件和死亡具有预后价值。
