心肌梗死后门诊患者的N末端脑钠肽前体：症状与左心室功能之间的相互作用及优化切点

NT-ProBNP in outpatients after myocardial infarction: interaction between symptoms and left ventricular function and optimized cut-points.

作者信息

Luchner Andreas, Hengstenberg Christian, Löwel Hannelore, Buchner S, Schunkert Heribert, Riegger Günter A J, Holmer Stephan

机构信息

Klinik und Poliklinik für Innere Medizin II, University of Regensburg, Regensburg, Germany.

出版信息

J Card Fail. 2005 Jun;11(5 Suppl):S21-7. doi: 10.1016/j.cardfail.2005.04.018.

DOI:10.1016/j.cardfail.2005.04.018

PMID:15948096

Abstract

BACKGROUND

N-terminal pro-brain natriuretic peptide (NT-proBNP) allows us to rule out left ventricular dysfunction (LVD) in the general population at a recommended cut-off concentration of 125 pg/mL. It was our objective to reassess this cut-point in outpatients after myocardial infarction.

METHODS AND RESULTS

NT-proBNP was assessed in 418 randomly selected outpatients who had experienced myocardial infarction and 352 siblings who had not experienced myocardial infarction (control). Left ventricular ejection fraction (LVEF) and mass-index (LVMI) were assessed by echocardiography. NT-proBNP was elevated in outpatients after myocardial infarction (mean [+/-SEM], 305 +/- 25 pg/mL vs control, 84 +/- 8 pg/mL; P < .01) and was correlated inversely with LVEF ( P < .001). When patients were stratified according to the presence or absence of heart failure, NT-proBNP was elevated significantly throughout all LVEF strata (each P < .05). On regression analysis, NT-proBNP was correlated independently with LVEF, LVMI, heart failure, and glomerular filtration rate (all P < .01). In patients with heart failure, the optimal cut-point for the detection of an LVEF <35% was 348 pg/mL (sensitivity 80%; specificity 69%) and for the detection of an LVEF <45% was 260 pg/mL (sensitivity 60%; specificity 60%). The relative risk for LVD in the presence of elevated NT-proBNP increased from 2.7 to 7.7 (EF < 35%) and from 1.4 to 2.4 (EF < 45%) when these cut-points were applied instead of the 125 pg/mL cut-point. An LVEF of <35% could be ruled out in symptomatic outpatients after myocardial infarction with a negative predictive value of 97% (cut-point 348 pg/mL) and in asymptomatic outpatients after myocardial infarction with a negative predictive value of 98% (cut-point 157 pg/mL).

CONCLUSION

NT-proBNP is higher in outpatients after myocardial infarction than in the general population. In symptomatic patients, a cut-point of 348 pg/mL yields satisfactory sensitivity and specificity for the detection of significant LVD (EF < 35%). Furthermore, significant LVD can be virtually ruled out in symptomatic and asymptomatic outpatients after myocardial infarction at below-threshold concentrations.

摘要

背景

N末端脑钠肽前体（NT-proBNP）使我们能够在一般人群中以推荐的125 pg/mL临界浓度排除左心室功能障碍（LVD）。我们的目的是重新评估心肌梗死后门诊患者的这一切点。

方法与结果

对418例随机选择的心肌梗死门诊患者和352例未发生心肌梗死的同胞（对照组）进行NT-proBNP评估。通过超声心动图评估左心室射血分数（LVEF）和质量指数（LVMI）。心肌梗死后门诊患者的NT-proBNP升高（均值[±标准误]，305±25 pg/mL vs对照组，84±8 pg/mL；P<.01），且与LVEF呈负相关（P<.001）。根据是否存在心力衰竭对患者进行分层时，在所有LVEF分层中NT-proBNP均显著升高（各P<.05）。回归分析显示NT-proBNP与LVEF、LVMI、心力衰竭和肾小球滤过率独立相关（所有P<.01）。在心力衰竭患者中，检测LVEF<35%的最佳切点为348 pg/mL（敏感性80%；特异性69%），检测LVEF<45%的最佳切点为260 pg/mL（敏感性60%；特异性60%）。当应用这些切点而非125 pg/mL切点时，NT-proBNP升高时LVD的相对风险从2.7增加到7.7（EF<35%），从1.4增加到2.4（EF<4）。心肌梗死后有症状门诊患者中LVEF<35%可被排除，阴性预测值为97%（切点348 pg/mL），心肌梗死后无症状门诊患者中阴性预测值为98%（切点为157 pg/mL）。