Mueller Thomas, Gegenhuber Alfons, Poelz Werner, Haltmayer Meinhard
Department of Laboratory Medicine, Konventhospital Barmherzige Brueder, Linz, Austria.
Clin Chem Lab Med. 2004 Feb;42(2):159-63. doi: 10.1515/CCLM.2004.029.
The aim of the present investigation was to evaluate the diagnostic accuracy of brain natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) for the detection of mild/moderate and severe impairment of left ventricular ejection fraction (LVEF). In 180 subjects BNP and NT-proBNP were measured by two novel fully automated chemiluminescent assays (Bayer and Roche methods). LVEF as determined by echocardiography was categorized as normal (> 60%), mildly/moderately reduced (35-60%) and severely diminished (< 35%). Discriminating between patients with LVEF< 35% (n = 32) and subjects with LVEF > or = 35% (n = 148), receiver-operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.912 for BNP and of 0.896 for NT-proBNP (difference 0.016, p = 0.554). In contrast, BNP displayed an AUC of 0.843 and NT-proBNP an AUC of 0.927 (difference of 0.084, p = 0.034) when comparing patients with LVEF 35-60% (n = 37) and individuals with LVEF > 60% (n = 111). Evaluation of discordant false classifications at cut-off levels with the highest diagnostic accuracy showed advantages for BNP in the biochemical diagnosis of LVEF < 35% (4 misclassifications by BNP and 25 by NT-proBNP, p < 0.001) and for NT-proBNP in the detection of LVEF 35-60% (25 misclassifications by BNP and 7 by NT-proBNP, p = 0.002). In conclusion, the present study indicates a different diagnostic accuracy of BNP and NT-proBNP for the detection of mildly/moderately reduced LVEF and severely diminished LVEF. Advantages of BNP may be advocated for the biochemical diagnosis of more severely impaired LVEF, while NT-proBNP might be a more discerning marker of early systolic left ventricular dysfunction.
本研究的目的是评估脑钠肽（BNP）和氨基末端脑钠肽前体（NT-proBNP）检测左心室射血分数（LVEF）轻度/中度和重度受损的诊断准确性。对180名受试者采用两种新型全自动化学发光分析法（拜耳法和罗氏法）检测BNP和NT-proBNP。通过超声心动图测定的LVEF分为正常（>60%）、轻度/中度降低（35%-60%）和重度降低（<35%）。在区分LVEF<35%的患者（n = 32）和LVEF≥35%的受试者（n = 148）时，受试者操作特征（ROC）曲线分析显示，BNP的曲线下面积（AUC）为0.912，NT-proBNP的曲线下面积为0.896（差异为0.016，p = 0.554）。相比之下，在比较LVEF为35%-60%的患者（n = 37）和LVEF>60%的个体（n = 111）时，BNP的AUC为0.843，NT-proBNP的AUC为0.927（差异为0.084，p = 0.034）。在诊断准确性最高的临界值水平评估不一致的错误分类时，发现BNP在LVEF<35%的生化诊断中具有优势（BNP有4例假分类，NT-proBNP有25例假分类，p<0.001），而NT-proBNP在检测LVEF为35%-60%时具有优势（BNP有25例假分类，NT-proBNP有7例假分类，p = 0.002）。总之，本研究表明BNP和NT-proBNP在检测轻度/中度降低的LVEF和重度降低的LVEF时诊断准确性不同。对于LVEF受损更严重的生化诊断，可能提倡使用BNP的优势，而NT-proBNP可能是早期收缩期左心室功能障碍更具辨别力的标志物。
