血BNP水平对慢性心力衰竭老年患者预后的影响

Prognostic value of blood brain natriuretic peptide level in the chronic heart failure in elderly patients

目的：探讨B型利钠肽（Brain natriuretic peptide，BNP）水平与慢性心力衰竭的老年患者预后的关系。方法选取我院2009年4月至2011年5月NYHA分级心功能Ⅱ~Ⅳ级的122例慢性心力衰竭老年患者，行血浆BNP、左室舒张末期内径、左室射血分数、血脂检查。比较不同心功能等级的BNP水平以及上述指标的差异。同时记录患者首次入院后2年内是否死于相关心脏疾病，绘制受试者工作特征曲线（ROC）。结果不同心功能等级的BNP水平为Ⅳ＆gt;Ⅲ＆gt;Ⅱ，且两两比较差异均有统计学意义（P〈0.05）。不同BNP水平与心功能不全的程度密切相关。高水平BNP组（≥1600 ng/L）与低水平（〈1600 ng/L）相比其左室射血分数降低（P〈0.05），左室舒张末期内径减少（P〈0.05），血中胆固醇、高密度脂蛋白、低密度脂蛋白均降低（P〈0.05）。BNP水平预测所有患者中入院两年内死于心脏疾病的ROC曲线下面积为0.748，其中通过Youden指数分析确定最佳工作点为1870 ng/L。BNP水平高于1870 ng/L的患者入院后两年内死于相关心脏疾病的概率是BNP小于1870 ng/L的患者的2.4倍。结论血浆BNP水平能较好反映慢性心力衰竭的老年患者左室功能状态，对其预后评估有一定价值。

Objective To investigate the relationship between the BNP level and the prognosis of elderly pa-tients with chronic heart failure. Methods A total of 122 elderly patients with chronic heart failure from April 2009 to May 2011, whose NYHA heart function classification was Ⅱ to Ⅲ level, were selected as research objects. The plasma BNP levels, left ventricular end-diastolic diameter, left ventricular ejection fraction, blood fat were tested. The level of BNP and other above index among the patients with different cardiac function grade were compared. Whether patients died of related heart disease in two years after first admission were recorded. And the receiver-operating char-acteristic curve drawing was made. Results The order of the BNP levels in different cardiac function： Ⅳ＆gt;Ⅲ＆gt;Ⅱ, and pairwise comparisons showed significant differences （P〈0.05）. The BNP levels was closely related to different de-gree of cardiac function. The left ventricular ejection fraction, left ventricular end-diastolic diameter, blood cholester-ol, high density lipoprotein and low density lipoprotein of high BNP level group were lower than those of the low BNP level group （P〈0.05）. The area under ROC curve, which used BNP levels to predict all hospitalized patients die within two years of heart disease, was 0.748. The optimum operating point was 1 870 mmol/L determined by Youden index. The probability of the patient died of heart related disease of the high BNP level （＆gt;1 870 ng/L） was 2.43 times of the low BNP level （≤1 870 ng/L）. Conclusion BNP levels could reflect the state of the left ventricular function in el-derly patients with chronic heart failure,and could help to assess the prognosis of the patients.