Tuğcu Aylin, Yildirimtürk Ozlem, Aytekin Saide
Department of Cardiology, Florence Nightingale Hospital, Istanbul, Turkey.
Turk Kardiyol Dern Ars. 2009 Mar;37(2):112-21.
We investigated the value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) to diagnose diastolic heart failure (DHF) without left ventricular (LV) hypertrophy.
The study included 33 patients (17 males, 16 females) with DHF, who had acute pulmonary congestion and LV ejection fraction (EF) >50% on admission, and were stable for at least six months of follow-up. The control group consisted of 18 hypertensive patients (9 males, 9 females) without cardiac symptoms, whose LV mass indices matched the study group, and EF was >50%. Plasma NT-proBNP levels were measured and all patients were evaluated by echocardiography to examine the relationship between NT-proBNP levels and the ratio of peak early diastolic mitral velocity to peak early diastolic mitral annular velocity (E/E').
NT-proBNP levels were significantly increased in the DHF group (293.4+/-52.1 pg/ml vs. 123.1+/-23.5 pg/ml, p=0.043). Concerning the severity of diastolic dysfunction and NT-proBNP levels, patients with delayed relaxation (n=24) did not differ from the controls, whereas those with pseudonormal (n=5) and restrictive (n=4) forms had significantly elevated NT-proBNP levels (p=011). In ROC analysis, an NT-proBNP level of = or >490 pg/ml predicted DHF with 40% sensitivity and 94% specificity. The mean E/E' values were 5.4, 15.4, and 17.6 in patients with delayed relaxation, pseudonormal, and restrictive forms, respectively. When all the patients were examined in three groups according to the E/E' values (E/E'<8; E/E'=8-15; E/E'>15), those having E/E' >15 had significantly higher NT-proBNP levels (p=0.0001). There was a highly significant relationship between E/E' and NT-proBNP (r=0.761, p=0.001). In ROC analysis, a threshold of 269.1 pg/ml for NT-proBNP predicted E/E' >15 with 90% sensitivity and 73% specificity. In logistic regression analysis, left atrial diameter (p=0.018) and E/E' (p=0.05) were independent factors affecting the NT-proBNP level.
Plasma NT-proBNP levels are elevated in DHF independently from LV hypertrophy. NT-proBNP levels provide estimation of LV end-diastolic pressure in symptomatic hypertensive patients with preserved systolic LV function.
我们研究了N末端B型利钠肽原（NT-proBNP）在诊断无左心室（LV）肥厚的舒张性心力衰竭（DHF）中的价值。
该研究纳入了33例DHF患者（17例男性，16例女性），这些患者入院时出现急性肺淤血且左心室射血分数（EF）>50%，并至少随访6个月病情稳定。对照组由18例无心脏症状的高血压患者（9例男性，9例女性）组成，其左心室质量指数与研究组匹配，EF>50%。测量血浆NT-proBNP水平，并通过超声心动图对所有患者进行评估，以检查NT-proBNP水平与舒张早期二尖瓣峰值流速与舒张早期二尖瓣环峰值流速之比（E/E'）之间的关系。
DHF组的NT-proBNP水平显著升高（293.4±52.1 pg/ml对123.1±23.5 pg/ml，p=0.043）。关于舒张功能障碍的严重程度和NT-proBNP水平，舒张延迟患者（n=24）与对照组无差异，而假性正常（n=5）和限制性（n=4）形式的患者NT-proBNP水平显著升高（p=0.011）。在ROC分析中，NT-proBNP水平≥490 pg/ml预测DHF的敏感性为40%，特异性为94%。舒张延迟、假性正常和限制性形式患者的平均E/E'值分别为5.4、15.4和17.6。当根据E/E'值（E/E'<8；E/E'=8-15；E/E'>15）将所有患者分为三组进行检查时，E/E'>15的患者NT-proBNP水平显著更高（p=0.0001）。E/E'与NT-proBNP之间存在高度显著的关系（r=0.761，p=0.001）。在ROC分析中，NT-proBNP阈值为269.1 pg/ml预测E/E'>15的敏感性为90%，特异性为73%。在逻辑回归分析中，左心房直径（p=0.018）和E/E'（p=0.05）是影响NT-proBNP水平的独立因素。
DHF患者血浆NT-proBNP水平升高，与LV肥厚无关。NT-proBNP水平可为有症状的左心室收缩功能保留的高血压患者的左心室舒张末期压力提供评估。
