急性心肌梗死患者血B型利钠肽水平与心功能的相关性和诊断心力衰竭的价值

目的 分析急性心肌梗死(AMI)患者B型利钠肽(BNP)水平与心功能指标的相关性,选择AMI后心功能的最佳预测指标.方法 顺序入选住院AMI患者230例及正常对照111例,测定BNP.按照心功能Killip分级、左室射血分数(LVEF)和左室舒张末径(LVEDd)进行分组,因BNP不符合正态分布,经自然对数(ln)处理后lnBNP符合正态分布,对比各组间lnBNP的差异;分析lnBNP与心功能指标的相关性;绘制受试者工作特性(ROC)曲线,确定诊断失代偿性左心功能衰竭及心原性休克的最佳指标和阈值.结果 AMI患者lnBNP随着Killip分级(Ⅰ～Ⅲ级)升高和LVEF的降低而梯次显著升高(均P<0.05),在LVEDd55 mill组显著高于≤55 mnl组(均P<0.01);InBNP、LVEDd、LVEF与Killip分级呈线性相关(均P<0.05),其中lnBNP的相关性最好(r=0.53,P<0.05),lnBNP与LVEDd(r=0.17,P<0.05)、LVEF也显著相关(r=-0.41,P<0.01).经多元回归分析显示,仅lnBNP是Killip分级的独立相关因素(P<0.01).ROC曲线分析后显示,lnBNP诊断失代偿性左心衰竭和心原性休克的曲线下面积(AUC)最大(P<0.01),有诊断价值.以BNP=140 ng/L为阈值时,诊断失代偿性左心衰竭的敏感性、阴性预测值和准确度分别为84.9%、75.3%和70.0%;当以BNP=400 ng/L为阈值时,诊断心原性休克的敏感性、阳性预测值和准确度分别为82.8%、72.4%和67.4%.结论 AMI患者BNP水平与Killip心功能分级、LVEDd呈正相关,与LVEF呈负相关,是诊断心力衰竭和排除诊断心原性休克的优良指标.

The relationship between plasma BNP level and the left ventricular dysfunction parameters in patients with acute myocardial infarction and it's value in diagonosing heart failure

Objective To explore the correlation between plasma BNP level and left ventricular dysfunction parameters in patients with acute myocardial infarction (AMI). Methods Plasma BNP level was determined in 230 consecutive inpatients with AMI and 111 normal controls. Patients were grouped according Killip grades, LVEF and LVEDd, respectively. BNP was transformed into lnBNP for the normal distribution. The receiver operator characteristic curve (ROC curve) was drawn to determine the best threshold and criteria for diagnosing heart failure. Results After AMI, lnBNP levels increased significantly in proportion with increasing Killip grades (Ⅰ-Ⅲ), and decreasing LVEF(all P<0.05). lnBNP level was significantly higher in LVEDd 55 mm group than in the LVEDd < 55 mm group (P<0.01). lnBNP, LVEDd and LVEF all linearly correlated with Killip grades (P<0.05) and the best correlation was shown between lnBNP and Killip grades(r=0.53, P<0.05). lnBNP also positively correlated with LVEDd(r=0.17 ,P<0.05) and negatively correlated with LVEF(r=-0.41, P<0.01). Among the parameters, InBNP level presented the largest AUC in their ROC curves(P<0.01)for diagnosing decompensated heart failure and cardiogenic shock. The sensitivity, specifiticity and accuracy rates for diagnosing decompensated heart failure were 84.9%, 45.0% and 70.0% respectively by lnBNP at the cut point of 140 ng/L The sensitivity, negative predicting value and accuracy rate for diagnosing cardiac shock were 82.8% ,66.7% and 67.4% respectively by BNP at the cut point of 400 ng/L. Conclusion lnBNP level in hospitalized patients with AMI was positively correlated with Killip grades and LVEDd,negatively correlated with LVEF and could serve as a parameter for diagnosing the decompensated heart failure and excluding the cardiac shock.