血浆心脏标志物对心源性呼吸困难的诊断价值

Utility of cardiac biomarkers in the diagnosis of cardiac etiologies of dyspnea

目的检测因急性呼吸困难就诊患者血浆心肌肌钙蛋白I(cTnI)和脑钠肽(B-type natriuretic peptide,BNP)水平,探讨cTnI和BNP对心源性呼吸困难的诊断价值。方法选取因急性呼吸困难就诊患者共129例,分为心源性呼吸困难组63例和非心源性呼吸困难组66例。测定所有患者血浆cTnI和BNP含量并进行组间比较。分析心源性呼吸困难组中logcTnI浓度和logBNP浓度与左室射血分数(LVEF)值的相关关系。绘制受试者工作特征曲线(ROC曲线)以评价cTnI和BNP对心源性呼吸困难的诊断价值。结果心源性呼吸困难组BNP值明显高于非心源性呼吸困难组(P<0.01)。心源性呼吸困难组血浆cTnI浓度高于非心源性呼吸困难组和正常对照组(P<0.01)。对于伴有收缩功能不全的心衰,logBNP水平与LVEF呈负相关(r=-0.739,P<0.01)。BNP对诊断心源性呼吸困难最佳阈值(112.68pg/mL)时的敏感性、特异性、阳性预测值和阴性预测值分别为94%、79%、81%和93%。ROC曲线下面积为0.941(P<0.01)。结论血浆BNP水平测定对于急性呼吸困难原因的鉴别有重要的意义,是诊断心源性呼吸困难的一项很有价值的指标。

Objective Plasma cardiac troponin I（cTnI） and B-type natriuretic peptide（BNP） levels were measured in patients with acute dyspnea.The value of cTnI and BNP for diagnosing cardiac dyspnea was assessed.Methods 129 patients with acute dyspnea were enrolled in this study.The diagnosis was cardiac dyspnea in 63 patients and noncardiac dyspnea in 66 patients.All patients underwent cTnI and BNP assay.The relation of logcTnI and logBNP levels with LVEF in cardiac dyspneic patients was assessed.The value of cTnI and BNP for the diagnosis of cardiac dyspnea was appraised.Results The BNP levels among patients in cardiac dyspneic group were significantly higher than those in noncardiac dyspneic group（P0.01）.The cTnI levels among patients in cardiac dyspneic group were significantly higher than those in noncardiac dyspneic group（P0.01）.In patients with systolic heart failure,the concentration of logBNP had a negative correlation with LVEF（r=-0.739,P0.01）.The optimal BNP cut-off value of 112.68 pg/mL for the diagnosis of cardiac dyspnea had a sensitivity of 94%,a specificity of 79%,a positive predictive value of 81% and a negative predictive value of 93%.The area under the ROC curve was 0.941（P0.01）.Conclusion Used in conjunction with other clinical information,measurement of B-type natriuretic peptide is valuable for diagnosing cardiac etiologies of dyspnea in patients with acute dyspnea.