Prognostic Value Of N-terminal Pro-brain Natriuretic Peptide In Patients With Diastolic Heart Failure

BackgroundLeft ventricular ejection fraction(LVEF)was the main evaluating indicator of cardiac systolic function and could reflect the severity of heart failure.But the systolic function of patients with diastolic heart failure (DHF) was kind, and the symptom of heart failure was caused by the obstruction of diastolic function. So the value of LVEF to the severity and prognosis of the patients with DHF was poor. N-terminal pro-brain natriuretic peptide(NT-proBNP) was a kind of peptide hormone endocrined by heart and had high clinic value to diagnosis and prognosis of heart failure. NT-proBNP could been detected at bedside quickly and was a independent prognosis factor of the patients with heart failure. NT-proBNP also had vital value of risk stratification, therapy indication and prognosis judgement to the patients with heart failure.ObjectiveTo evaluate the prognostic value of NT-proBNP in patients with DHF.Methods176consecutive hospitalized patients from the Internal medicine-cardiovascular Department in second affiliated hospital of ZHEJIANG university school of medicine, whom present signs or symptoms of heart failure with complete case record from July2010to July2011, were collected for a retrospective study. On the basis of different diagnosis, they were divided into two groups:research group (patients with signs or symptoms of heart failure, LVEF>50%and diagnosed to be DHF,82cases,44males and38females, mean age70.1±9.4years) and control group (patients with signs or symptoms of heart failure, LVEF<50%and diagnosed to systolic heart failure (SHF),94 cases,54males and40females, mean age64.9±11.5years), according to diagnosis. The clinical characters, such as age, gender, internal diseases kinds, NYHA classes, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and medical therapy, were compared between two groups. The values of left ventricular end-diastolic dimension (LVEDd), LVEF, ventricular early diastolic filling velocity (E peak), ventricular late diastolic filling volume velocity (A peak), E/A ratio were compared between two groups by Doppler echocardiography. The values of cardiac troponin i (cTnl), creatine kinase isoenzyme (CK-MB), glycerin trimyristate (TG), cholesterol total (CHOL), NT-proBNP were compared between two groups by electrochemiluminescence immunoassay. All patients discharged were followed up for6months and divided into two groups, recurrence group and non-recurrence group, according to recurrence of signs or symptoms of heart failure. The values of age, gender, internal diseases kinds, NYHA classes, SBP, DBP, HR, NT-proBNP, CK-MB, cTnl, TG, CHOL were compared between two groups.Results1. Compared to control group, the clinical feature of age, SBP, DBP, HR, CK-MB, the ratio of hypertensive heart disease (HHD), type2diabetes mellitus (T2DM), essential Hypertension (EH), atrial fibrillation (AF) and the parameters of E/A ratio, LVEDD, LVEF were higher to research group(P<0.05). And the clinical feature of male ratio, NYHA classes, admission NT-proBNP levels and DCM ratio, cardiac death ratio, recurrence ratio were lower to research group(P<0.05). And the clinical feature of body weight, cTnl, TG, CHOL and the ratios of CHD and HCM were no difference between two groups(P>0.05).2. Compared to control group companied with the diseases of HHD, EH and AF, the plasma levels of NT-proBNP were lower to research group companied with the diseases of HHD, EH and AF (P<0.05). But compared to control group companied with the diseases of CHD, DCM, HCM and T2DM, the plasma levels of NT-proBNP were no difference to research group companied with the diseases of CHD, DCM, HCM and T2DM (P>0.05).3. The plasma levels of NT-proBNP had the positive correlation to age, NYHA classes, CHD, AF, LVEDD, SBP, DBP, HR and CK-MB (P<0.05), but had the negative correlation to LVEF (P<0.05).4. Compared to non-recurrence group, the clinical feature of age, male ratio,3/4classes of NYHA, SBP, DBP, CK-MB, admission NT-proBNP levels and the ratios of CHD, HHD, T2DM, EH, AF were higher to recurrence group(P<0.05). But the clinical feature of HR, cTnI, TG, CHOL, the ratios of DCM and HCM were no difference between two groups (P>0.05).5. The clinical parameters of this research were analyzed by COX proportional hazard model. The level of LgNT-proBNP was the independent hazard factor of cardiovascular events (OR=2.586,95%CI:1.621-4.011, P=0.002). The level of LVEF was the independent protective factor of cardiovascular events (OR=0.501,95%CI:0.198-1.003, P=0.042).And the other indexs were no independent hazard factor of cardiovascular events.6. On a Kaplan-Meier survival curve, the median level of NT-proBNP to1369.6pg/ml was the dividing value associated with increased recurrent cardiac events. The risk of cardiovascular events recurrence to patients with NT-proBNP>1369.6pg/ml was3.339multiple to patients with NT-proBNP<1369.6pg/ml(95%CI:1.694-5.752, P=0.003).Conclusion Plasma NT-proBNP level were independent predictors of readmission and cardiac death after hospital discharge in patients with DHF.