N末端脑钠肽前体与左心室射血分数联合试验在急性呼吸困难快速诊断中的应用

目的 探讨N末端脑钠肽前体对急性呼吸困难的鉴别诊断价值,并寻求其对心力衰竭引起的急性呼吸困难快速诊断的切点.方法 将2008年1-6月来我院急诊就诊的呼吸困难患者91例分为心源性呼吸困难组(心源性组34例)、非心源性呼吸困难组(非心源性组57例).评价各参数对于急诊呼吸困难鉴别诊断的价值,并通过对各参数与心源性呼吸困难的关系进行ROC曲线分析,最终获得各参数对于心源性呼吸困难的最佳诊断范围.结果 心源性组与非心源性组患者的N末端脑钠肽前体(6203.50、1410.00ng/L)、肌钙蛋白Ⅰ(0.12、0.03 μg/L)、左心室射血分数(46.25%、65.60%)、左房内径(42.75、36.00 mm)差异均有统计学意义(P均＜0.01).对于心源性呼吸困难,以N末端脑钠肽前体值≥3715 ng/L为切点,其灵敏度及特异度达到最大值.根据ROC曲线分析,N末端脑钠肽前体及左心室射血分数是诊断心源性呼吸困难的最佳指标.N末端脑钠肽前体ROC曲线下面积为0.828±0.045(P＜0.01),左心室射血分数ROC曲线下面积0.829±0.049(P＜0.01).N末端脑钠肽前体和左心室射血分数对心源性呼吸困难进行联合试验,其特异度上升为96.50%,总符合率上升为83.50%,阳性预测值上升为91.30%,阳性似然比上升为17.60,误诊率下降为3.50%.结论 急诊检测N末端脑钠肽前体有利于对急性呼吸困难患者做出快速诊断,有助于快速鉴别患者的呼吸困难是否为急性充血性心力衰竭引起.

Rapid diagnosis of acute dyspnea using the combined test of NT-pro-BNP and left ventricular ejection fraction

Objective To investigate the value of N-termind pro-B-type natriuretic peptide(NT-pro-BNP)in differential diagnosis of dyspnea in emergency department, and to investigate the rapid diagnosis cutoff of dyspnea due to acute congestive heart failure. Methods Ninety. one cases of dyspnea in emergency department recruited from January to June ,2008 were divided into two groups: acute cardiac dyspnea group and none acute cardiac dyspnea group. To evaluate the value of different parameters in differential diagnosis of dyspnea in emergency department and analysis the area under the receiver-operating characteristic of different parameters for the diagnosis of acute cardiac dyspnea. To achieve the best cutoff of different parameters for the diagnosis of dyspnea due to acute congestive heart failure finally. Results Among two groups, NT-pro-BNP (acute cardiac dyspnea vs. none acute cardiac dyspnea,6203.50 ng/L vs. 1410.00 ng/L,P ＜ 0.01), Troponin Ⅰ (acute cardiac dyspnea vs. none acute cardiac dyspnea,0.12 μg/L vs. 0.03 μg/L,P ＜0.01) ,left ventricular ejection fraction(acute cardiac dyspnea vs. none acute cardiac dyspnea,46.25% vs. 65.60%, P ＜ 0.01), left atrial diameter (acute cardiac dyspnea vs. none acute cardiac dyspnea,42.75 mm vs. 36.00 mm,P ＜0.01) had significant difference. NT-pro-BNP at cutoff of ≥3715 ng/L was highly sensitive and specific for the diagnosis of acute cardiac dyspnea. Receiver-operating characteristic analyses demonstrated that NT-pro-BNP and left ventricular ejection fraction was the best diagnostic indices of acute cardiac dyspnea. The area under the receiver-operating characteristic curve of Nt-pro-BNP was 0.828 ± 0.045 (P ＜ 0.01),and left ventricular ejection fraction was 0.829 ± 0.049 (P ＜ 0.01). Correlation analysis showed that NT-pro-BNP was correlated with left ventricular ejection fraction (P ＜ 0.01). The combined test of NT-pro-BNP and left ventricular ejection fraction was performed. Specificity increased to 96.50%, total consistent rate increased to 83.50% ,positive predictive value increased to 91.30%, positive likelihood ratio 17.60, faulse diagnostic rate decreased to 3.50%. Conclusions NT-pro-BNP examination in emergency department was helpful to rapid differential diagnosis of dyspnea. It helped to differentiate the patients with acute congestive heart failure and none acute congestive heart failure causes of dyspnea.