6 min步行试验联合血浆N-末端前体脑钠肽评估慢性心力衰竭患者预后的价值

Clinical value of the 6-minute walk test combined with plasma N-terminal pro-brain natriuretic peptide in evaluating the prognosis of patients with chronic heart failure

目的探讨6 min步行试验(6MWT)联合血浆N-末端前体脑钠肽(NT-proBNP)评估慢性心力衰竭(CHF)患者预后的临床价值。方法选取CHF患者93例,男51例,女42例,其中NYHA分级Ⅱ级51例、Ⅲ级42例。于CHF患者治疗前分别进行6MWT试验、血浆NT-proBNP和左心室射血分数(LVEF)测定,随访CHF患者6个月到1年,统计CHF急性加重住院及心脏事件(心源性休克、心源性晕厥、心源性猝死)发生情况,分析6MWT、NT-proBNP及LVEF的相关性。结果心功能Ⅲ级患者的6MWT、LVEF均低于心功能Ⅱ级患者相应水平,而血浆NT-proBNP高于心功能Ⅱ级患者相应水平(t=4.05~11.23,P<0.01或<0.05)。根据6MWT及血浆NT-proBNP水平参考值范围,再分为3组:分别为6MWT<425 m+ NT-proBNP<900 ng/L组(A组,30例)、6MWT>425 m+NT-proBNP>900 ng/L组(B组,30例)、6MWT<425 m+NT-proBNP>900 ng/L组(C组,33例)。C组患者CHF急性加重住院及心脏事件发生率均高于A、B组(χ2=3.95~7.20,P<0.01或<0.05);A组患者CHF急性加重住院发生率均高于B组(χ2=3.17~4.26,P<0.05)。Pearson相关分析显示,CHF患者LVEF与6MWT呈正相关(r=0.53,P<0.01),LVEF与血浆NT-proBNP呈负相关(r=-0.41,P<0.01),6MWT与血浆NT-proBNP呈负相关(r=-0.87,P<0.01)。结论 6MWT及血浆NT-proBNP均是反映CHF严重程度的敏感指标,二者呈负相关,低6MWT和血浆NT-proBNP高反映CHF患者预后较差。两种方法联合应用可能具有更高的敏感性和特异性,对CHF患者的预后预测具有较好的临床应用价值。

Objective To investigate the clinical value of the 6-minute walking tcst(6MWT)combined with plasma N-terminal pro-brain natriuretic peptide(NT-proBNP)in evaluating the prognosis of patients with chronic heart failure(CHF).Methods A total of 93 CHF cases were enrolled with 51 males and 42 females,among them 51 were in NYHA gradeⅡ,42 were in gradeⅢ.Patients with CHF performed the detection of 6MWT test,plasma NT-proBNP and left ventricular ejection fraction(LVEF)before treatment.The incidence rate of acute exacerbation of CHF in hospital,and cardiac events such as cardiogenic shock,cardiogenic syncope and sudden cardiac death were recorded in patients with CHF during the follow-up of 6 months to 1 year.The correlations of 6MWT and NT-proBNP with LVEF were analyzed.Results The levels of 6MWT and LVEF were lower,while the plasma NT-proBNP levels were higher in patients with NYHA gradeⅢthan in those with NYHA gradeⅡ(t=4.05-11.23,P<0.01 or 0.05).According to the reference ranges of 6MWT and plasma NT-proBNP level,patients were divided into three groups:6MWT<5425 m 4-NT-proBNP<900 ng/L group(group A,n=30),6MWT>425m NT-proBNP>900 ng/L group(group B,n=30),6MWT<425m+NT-proBNP>900 ng/L group(group C,n=33).The incidence rates of a CHF acute exacerbation and cardiac events were higher in group C than in group A and B(χ^2=3.95-7.20,P<0.01 or 0.05).The incidence rates of an acute exacerbation of CHF and cardiac events were higher in group A than in group B(χ^2=3.17-4.26,P<0.05).Pearson correlation analysis showed that LVEF was positively correlated with 6MWT(r=0.53,P<0.01)and was negatively correlated with plasma NT-proBNP(r=-0.41,P<0.01),and 6MWT was negatively correlated with plasma NT-proBNP(r=-0.87,P<0.01).Conclusions Both the 6MWT and plasma NT-proBNP are sensitive indexes to reflect the severity of CHF,and there is a negative correlation between them.The low 6MWT and high plasma NT-proBNP levels can reflect a poor prognosis in patients with CHF.The combined application of 6MWT and plasma NT-proBNP may have higher sensitivity and specificity and has a better clinical value in predicting the prognosis of CHF patients.