Shaikh Kaleemullah, Hanif Bashir, Siddique Ali Akber, Shaikh M Yousuf, Khan M Noman
Department of Cardiology, Tabba Heart Institute, Karachi.
J Coll Physicians Surg Pak. 2012 Dec;22(12):751-5.
To determine the association of the pro-brain natriuretic peptide (NT-proBNP) plasma levels with twodimensional echocardiographic determination of left ventricular dimensions and ejection fraction (EF) in acute dyspneic patients.
An observational cross-sectional study.
Tabba Heart Institute, Karachi, from January to June 2010.
One hundred patients were selected by consecutive purposive non-probability sampling who had presented with acute dyspnoea. NT-proBNP levels were assessed by commercial tests (Roche Diagnostics). The clinical diagnosis of congestive heart failure (CHF), echocardiographic assessment of left ventricular dimensions and function were compared with NT-proBNP levels. Receiver operating characteristic (ROC) curve was estimated for NT-proBNP and compared. The chi-square test was applied for categorical and student's t-test for numerical data at 0.05 levels of significance were used to compare patients with and without heart failure. Further comparative analysis between groups on the basis of ejection fraction was done by one way ANOVA test.
Seventy-nine patients (79%) had CHF as a cause of their dyspnoea. Patients with CHF were older (61.9 ± 14 years vs. 58.6 ± 14 years, p=0.368), had a lower EF (36.9% vs. 61%, p < 0.0001), had a higher LV dimensions, left ventricular end diastolic dimension - LVEDD (49.94 ± 5.6 vs. 42 ± 7.9 mm, p < 0.0001), left ventricular end systolic dimension - LVESD (37.31 ± 6 vs. 29.21 ± 10.9 mm, p < 0.0001) and a higher NT-proBNP (10918 ± 1228 vs. 461 ± 100 pg/mL, p < 0.0001) than patients without CHF. NT-proBNP values increased with the severity of ventricular impairment. Significant differences were found between patients with LVEF < 25 % and patients with moderate ventricular impairment (LVEF = 26 - 40%) and mild ventricular impairment (LVEF = 41-60%, p < 0.001). The group of patients with LV dilation, had significantly higher BNP levels than those with normal LVEDD (12416 ± 1060 pg/ml vs. 6113 ± 960, p = 0.009) and LVESD (10416 ± 1160 vs. 4513 ± 960 pg/ml, p = 0.008). Area under ROC curve for the diagnosis of CHF was significantly higher for NT-proBNP (AUC 0.99, p < 0.003). The sensitivity of NT-proBNP value of > 300 pg/mL for the diagnosis of CHF was 100% and specificity was 42%. A cut-point of 300 pg/mL NT-proBNP had 100% negative predictive value to exclude acute CHF.
NT-proBNP is strongly associated with two-dimensional echocardiographic determination of left ventricular dimensions and EF in identifying CHF in patients with acute dyspnoea.
确定急性呼吸困难患者血浆中脑钠肽前体（NT-proBNP）水平与二维超声心动图测定的左心室尺寸及射血分数（EF）之间的关联。
一项观察性横断面研究。
2010年1月至6月，卡拉奇塔巴心脏研究所。
通过连续的目的性非概率抽样选取100例急性呼吸困难患者。采用商业检测方法（罗氏诊断）评估NT-proBNP水平。将充血性心力衰竭（CHF）的临床诊断、左心室尺寸及功能的超声心动图评估与NT-proBNP水平进行比较。估算NT-proBNP的受试者工作特征（ROC）曲线并进行比较。采用卡方检验分析分类数据，采用学生t检验分析数值数据，以0.05的显著性水平比较有心力衰竭和无心力衰竭的患者。基于射血分数在组间进行进一步的比较分析采用单因素方差分析。
79例（79%）患者因CHF导致呼吸困难。CHF患者年龄较大（61.9±14岁对58.6±14岁，p = 0.368），EF较低（36.9%对61%，p < 0.0001），左心室尺寸较大，左心室舒张末期内径-LVEDD（49.94±5.6对42±7.9mm，p < 0.0001），左心室收缩末期内径-LVESD（37.31±6对29.21±10.9mm，p < 0.0001），且NT-proBNP水平较高（10918±1228对461±100pg/mL，p < 0.0001），均高于无CHF的患者。NT-proBNP值随心室功能损害的严重程度增加。左心室射血分数（LVEF）<25%的患者与中度心室功能损害（LVEF = 26 - 40%）和轻度心室功能损害（LVEF = 41 - 60%）的患者之间存在显著差异（p < 0.001）。左心室扩张组患者的BNP水平显著高于左心室舒张末期内径（LVEDD）正常组（12416±1060pg/ml对6113±960，p = 0.009）和左心室收缩末期内径（LVESD）正常组（10416±1160对4513±960pg/ml，p = 0.008）。NT-proBNP诊断CHF的ROC曲线下面积显著更高（AUC 0.99，p < 0.003）。NT-proBNP值>300pg/mL诊断CHF的敏感性为100%，特异性为42%。NT-proBNP 300pg/mL的切点对排除急性CHF具有100%的阴性预测价值。
在识别急性呼吸困难患者的CHF时，NT-proBNP与二维超声心动图测定的左心室尺寸及EF密切相关。
