N末端B型利钠肽原对主动脉瓣狭窄患者诊断价值

Clinical value of NT-proBNP in the diagnosis and analysis of correlation of NT-proBNP with clinical and echocardiographic findings in patients with aortic stenosis

目的 评价N末端B型利钠肽原（NT-proBNP）对主动脉瓣狭窄（AS）患者的诊断价值,分析NT-proBNP与美国纽约心脏协会（NYHA）心功能分级和超声心动图所测指标的相关性.方法 2005年5月至2006年7月因AS住院患者,使用酶联免疫的方法对40例AS患者（AS组）和76名健康对照者（正常组）行NT-proBNP测定.评价NT-proBNP对AS的诊断价值,及其与临床心功能分级、超声心动图指标的相关性.结果 AS组的NT-proBNP水平比正常组显著高（P＜0.01） 在NYHA心功能Ⅱ、Ⅲ和Ⅳ级者呈逐级显著高（均P＜0.01）,轻中度狭窄组高3.5倍[（2.95±0.48）ng/L比（2.63±0.10）ng/L,P＜0.05],重度狭窄组高6倍[（3.16±0.50）ng/L,P＜0.01） 伴随左室质量指数（LVMI）也显著高于正常组,且在轻、中度狭窄组高1.7倍[（169±51）比（100±22）,P＜0.01],重度狭窄组高2.1倍[（212±86）ng/L比（100±22）ng/L,P＜0.01].当NT-proBNP阈值在1150 ng/L和1356 ng/L时,分别是诊断轻、中度（AUC=0.657,P＜0.05）及重度AS（AUC=0.848,P＜0.01）的最佳阈值 诊断的敏感性、特异性和准确性分别为61.11%和77.30%,69.74%和96.10%以及68.09%和91.80%.单因素分析,Log（NT-proBNP）与左室舒张期末内径（LVEDD）、LVMI和平均主动脉瓣跨瓣压差（MTPG）均呈显著正相关（r=0.325,均P＜0.05）,而与左室射血分数（LVEF）呈负相关（r=-0.487,P=0.01） 多元逐步回归分析不仅与NYHA分级和LVEF,而且Log（MTPG）与NT-proBNP独立相关（P＜0.05）.结论 NT-proBNP对AS患者有诊断价值,不仅与心功能相关,还与AS的严重程度相关.

Objective To evaluate the diagnostic value of NT-proBNP in patients with aortic stenosis （AS） , analyze the relation of NT-proBNP to NYHA functional class and echocardiographic findings. Methods Measured the whole venous blood of NT-proBNP with enzyme linked immuno sorbent assay in 40 aortic stenosis patients （ AS group） and 76 normal subjects （ control group）. We assessed the diagnostic value of NT-proBNP for aortic stenosis, and related NT-proBNP to clinical NYHA functional class and echocardiographic findings. Results Compared to controls, NT-proBNP levels had significantly higher in patients with aortic stenosis （ P 〈 0. 01 ）. The level of NT-proBNP was gradually and significantly increased with the NYHA functional Ⅱ , Ⅲ and Ⅳclass compared to controls （all P 〈0. 01 ）. NT-proBNP was significantly （3.5 times） higher in mild/moderate stenosis group than that in control group（2. 95 ± 0. 48 vs 2.63 ±0. 10, P 〈0. 05）, and was significantly （6.0 times） higher in severe stenosis group than that in control group（3.16 ±0. 50 vs 2. 63 ±0. 10,P 〈0. 01 ）. LVMI was significantly （ 1.7 times） higher in mild/moderate stenosis group than that in control group（ 169 ±51 vs 100 ±22, P 〈0. 01 ）, and was significantly （2.1 times） higher in severe stenosis group than that in control group（212 ± 86 vs 100 ± 22, P 〈 0. 01 ）.The NT-proBNP values of 1150 ng/L and 1356 ng/L were determined as the best cutoff values for the diagnosis of patients with mild/moderate （ AUC = 0. 657, P 〈 0. 05 ） and severe aortic stenosis （ AUC = 0. 848,P 〈0. 01 ）, the sensitivity, specificity and accuracy were 61.11% and 77. 30% ,69.74% and 96. 10%,68.09% and 91.80%. Log（NT-proBNP） was significantly positively related with LVEDD, LVMI and mean transvalvular pressure gradient（MTPG） （ all P 〈 0. 05 ）, and negatively related with LVEF （ P = 0. 01 ） in univariate analysis. In multiple regression analyses, NYHA functional class, LVEF and Log（MTPG） was independently associated with NT-proBNP. Conclusion NT-proBNP is valuable for the diagnosis of patients with aortic stenosis. NT-proBNP has correlation with the heart function and severity of the aortic stenosis.