The Changes Of Plasma NT-proBNP In Patients With Ventricular Septal Defect And Sever Pulmonary Hypertension Undergoing Cardiac Surgery

Background and ObjectiveVentricular septal defect (VSD) is a common kind of congenital heart disease, covers approximately 25%-30%.VSD often causes pulmonary hypertension(PH). Depending on the size of the defect, the magnitude of the left-to-right shunt, and the pulmonary vascular response to the increased pulmonary flow and pressure, PH of patients with VSD rises at different age. When pulmonary arterial systolic pressure is over 30mmHg or pulmonary arterial mean pressure is over 20mmHg, PH exists. Operation of closuing the VSD is the only effective method that hold back the development of PH. But in our country ,the diagnosis and surgical treatment of children with VSD are often delayed because of variety of reasons. This circumstance puts these children at increased risk for significant morbidity and mortality when closure of the VSD is performed.N-terminal pro-brain natriuretic peptide(NT-proBNP)with no biological activity is the best cardiac marker in the diagnosis, risk stratification, prognosis and therapeutic monitoring of the patients with cardiac dysfunction, and is one of the natriuretic peptides.We try to determine NT-proBNP levels in patients with ventricular septal defect and sever pulmonary hypertension undergoing cardiac surgery and if those levels are related to any of the baseline clinical characteristics of patients before surgery and any of the outcomes or events after surgery. We want to look out the correlation of the preoperatory NT-proBNP datas and pulmonary arterial pressure and pathological grade, if perioperative NT-proBNP concentrations can be a predictor of selecting operation.Materials and Methods20 cases of control group which had normal blood Rt,ECG,color Doppler ultrasound and X-ray check had no deviation in the age and sex were selected from the patients in the prevent surgery. 36 cases of VSD in hospital were enrolled from the patients in the Cardiology surgery of the second affiliated hospital of ZhengZhou University, patient groups were named light pulmonary hypertension group (<50mmH g)and severe pulmonary hypertension (>50mmHg) group according to the color Doppler ultrasound,and the third group were thoughted of no operation choice diagnosed by color Doppler ultrasound,ECG,X-ray,blood-gas,et al. All samples were collected before any therapy.All patients have inhaled oxygen, injected PGE₁ during the perioperative period.Duration of operation procedure, aortic cross-clamp time, bypass time,ventilative time, et al, was recorded. Observating the symptom of the pulmonary hypertension crisis and right ventricular failure and treated. Follow-up 1-24 months. Echocardiography was used to assess the effect.We analysis all the datum with SPSS11.0 For Windows.Results(1) The plasma NT-proBNP in patient group is higher than the contrast group (t=21.01,P < 0.001). The plasma NT-proBNP and pulmonary arterial pressure in B group are higher than the A group (t=6.03,t=3.91,P < 0.01,P < 0.01).There is a positive rank correlation between the quantity of plasma NT-proBNP and the value of the pulmonary pressure (r=0.799, P<0.01) .(2) After operation vasoactive agent medicine, ventilative time in B group were longer than that in A group (t=6.34,t=7.4,P < 0.01,P < 0.01). There was no early mortality in A group, and the pulmonary hypertension crisis exist 1 case. In B group, 2 patients died because of the pulmonary hypertension crisis after the operation, and the pulmonary hypertension crisis exist 9 case. The mortality and complication of operation in B group is higher than A group ( x²= 11.63,P=0.01) .(3) Two weeks after operation,the plasma NT-proBNP and pulmonary arterial pressure in B group is higher than the A group (t=3.42,t=4.57,P < 0.05,P < 0.01), and there is a positive rank correlation between the quantity of plasma NT-proBNP in B group and the value of the pulmonary pressure (r=0.642,P < 0.01) , when they were leaving hospital.(4) The results in 6 month: the quantity of blood NT-proBNP and the value of the pulmonary pressure inclined to normal ranges except 2 cases from B group,which did not change to before operation.(5) The results of the pulmonary artery pathoanatomical rank:A group, there are 4 cases fromI ,9 cases from and 2 cases fromIII; B group, there are 3 cases fromII, 10 cases from III and 2 cases from IV. There is a positive rank correlation between the pulmonary artery pathoanatomical grade and the quantity of plasma NT-proBNP and the value of the pulmonary pressure (r_s=0.701,r_s=0.585,P < 0.01,P < 0.01,) .Conclusions(1) The content of plasma NT-proBNP in the patients with ventricular septal defet increase significantly,and the content of plasma NT-proBNP of the severe pulmonary hypertension group is higher than in the light pulmonary hypertension group;(2) There is a positive rank correlation between the quantity of plasma NT-proBNP and the value of the pulmonary pressure and the pulmonary artery pathoanatomical grade;(3) The mortality and complication after operation is higher in the group ,and their NT-proBNP cintent is higher. So the content of plasma NT-proBNP may be as an objective parameter to provide a predictor of selecting operation in clinical practice.