The Surgical Treatment Of The Heart Valve Disease Combined With Large Left Ventricle

Background:Heart valve disease is common in China and the incidence is very high.Heart valve replacement is the most effective way to treat this disease.As the knowledge of this disease, the surgical technique,myocardial protection technique,extracorporeal circulation,and treatment of the preoperational complications are improved,the outcome of the heart valve replacement has become better.However,the incidence of the complications and the mortality in the early time after operation are still high,and the results about the late efficacy are different.In the severe patients with heart valve disease,the myocardial protection during the operation is still the focus.At present,retrograde cardioplegia via coronary sinus is usually used in the heart valve replacement in patients with aortic insufficiency combined with large left ventricle.Because of the influence of the traditional ideas,the antegrade cardioplegia is used unusually.The present study is to analyze the risk factors of the mortality in the early time after the heart valve replacement in patients with large left ventricle retrospectively,to investigate the best myocardial protective way,to analyze the late efficacy and the anticoagulation through follow-up.Methods:The first part of this study is clinic retrospective research.The SPSS 10.0 statistical software was used in this part.Clinic materials were collected in157 patients with heart valve replacement combined with large left ventricle from January,1996 to April,2005. The sexuality,etiological factors,pathological characters,operation mode,the type of mechanical valve,myocardial protection way,the duration of the extracorporeal circulation, the time of aortic clamping and complications were analyzed for the mortality early after operation.The second part is the prospective study.The efficacy of the different myocardial protection ways was investigated in 18 cases of heart valve replacement combined with large left ventricle.All the patients in this part were male,who were divided into two groups,including the intermittent antegrade cardioplegia group and the retrograde cardioplegia group.There were 9 patients in each group.The observing markers included clinical efficacy(complication and early mortality,NYHA classification,the diameter of the left ventricle at the end of the diastolic phase,the EF and the FS from echo),CK-MB, cTnI,lactic acid concentration in blood,MVO₂.The last part is also prospective research.146 surviving patients with heart valve replacement combined with large left ventricle from January,1996 to April,2005 were followed up for the late efficacy and anticoagulation with the methods,like reexamination and follow up through telephone or letter.The risk factors affecting the late surviving incidence and the efficacy were analyzed.The evaluation indexes of the clinical efficacy included the NYHA classification,the self-evaluation on the efficacy from the patients,the occurrence of the severe events.The echocardiography was used to detect the diameter of the left ventricle at the end of the diastolic phase,the EF and the FS.Results:The first part:1.The early mortality in 157 patients was 7.01%(11/157),which was much higher than that in patients(1.56%(21/1350) ) with heart valve replacement and without large left ventricle(p＜0.05).2.The risk factors for the early death after operation included male,infective endocarditis,NYHAâ…£cardiac function,the diameter of the left ventricle at end of the diastolic phase≥8.0cm,EF of the left ventricle＜50%or the FS＜30%,double valve replacement,the time of cardiopulmonary bypass＞130min,the time of aortic clamping＞90min and retrograde cardioplegia.3.The analysis for the cause of the early death showed that ventricular fibrillation,low cardiac output syndrome and MODS were the main causes of the early death in these patients.6 patients died of ventricular fibrillation and heart arrest(54.54%(6/11) ),which was the capital cause of the early death.The second part:1.2 patients from the two groups died early after heart valve replacement in all the 18 patients with lager left ventricle.The other patients recovered well.There were no significant difference in cardiopulmonary bypass time,the time of aortic clamping, complication after operation,ventilation assisting time,hospital time,recover of cardiac function between the two groups(p＞0.05).The echo showed that the diameter of the left ventricle at the end of the diastolic phase decreased compared to that before operation (p＜0.05).The cardiac function of patients in the antegrade cardioplegia group recovered better.2.Serum CK-MB and cTnI levels before aortic clamping were higher than those before operation in the two groups(p＜0.05).After the clamp,the levels increased further and get to the peak at the first day after operation.At the third day after operation,these two markers returned to the levels before the aortic clamping.The antegrade cardioplegia group had the lower serum concentration of CK-MB and cTnI on the 10^th min after the opening of aorta and the first day after operation,compared to the retrograde cardioplegia group.3.The MVO₂ decreased significantly 40 min after the aortic clamping in the two groups(p＜0.05).The MVO₂ increased 10min after the opening of the aorta,which was lower than that before the clamping(p＜0.05).The MVO₂ in the antegrade cardioplegia group was little higher than that in the retrograde cardioplegia group,but the difference was not significant(p＞0.05).4.The lactic acid concentration in arterial blood and the blood from coronary sinus was much higher after the clamping than before the clamping(p＜0.05).The lactic acid concentration in the antegrade cardioplegia group was lower than that in the retrograde cardioplegia group at the 10^th min after the opening of the aorta(p＜0.05).The third part:1.125 patients were successfully followed up in 146 patients.The average follow-up time was 3.29 years.The main complications after heart valve replacement in patients with large left ventricle included arrhythmia and decreasing of the cardiac function,bleeding, embolism and infective endocarditis.10 patients died and the late mortality was 2.43%pt-yr. One of the causes of death was ventricular fibrillation.However,some patients suddenly died of unknown events.2.The results of follow-up showed that 91.30%of all the patients got the better cardiac function(NYHAâ… -â…¡),compared to that before operation(p＜0.05 ),98.26%of all the patients thought that the treatment was effective.The proportion of NYHAâ…¢-â…£cardiac function in the patients with double valve replacement was higher than that in the patients with mitral or aortic valve replacement(p＜0.05).The echo showed that 115 surviving patients had the smaller left ventricle,compared to that before operation(p＜0.05).EF and FS were improved significantly,too(p＜0.05).However,the improvement of cardiac function in patients with double valve replacement was less than that in patients with mitral or aortic valve replacement(p＜0.05).3.It was found that male patients,dysfunction of left ventricle and double valve replacement led to the higher late mortality(p＜0.05) Irregular monitoring of anticoagulation led to the higher incidence of anticoagulation related complications (p＜0.05)Conclusions:1.The early mortality was high in this group of patients with large left ventricle after heart valve replacement,but the outcome was still satisfactory.The risk factors for the early death after operation included male patients,infective endocarditis,dysfunction of the heart, double valve replacement,and the long duration of cardiopulmonary bypass and aortic clamping.The main causes of the early death included ventricular fibrillation,low cardiac output syndrome and MODS.2.The key measures to improve the early treatment efficacy in patients with large left ventricle after heart valve replacement included the accurate opportunity of operation, satisfactory myocardial protection,proficient surgical skills,active and reasonable prevention and treatment of complications.3.In the patients with large left ventricle and undergoing heart valve replacement,the antegrade cardioplegia through coronary artery could led to the better recovery of cardiac function,the lighter myocardial injury and better maintenance of the myocardiac metabolism,compared to the retrograde cardioplegia through coronary sinus.Therefore, antegrade cardioplegia through coronary artery is a convenient and effective cardioprotective way.4.The late efficacy of this group of patients was fairly satisfactory.The risk factors for the late death included male patients,double valve replacement,dysfunction of the heart before operation.The main causes of the late death included ventricular fibrillation, refractory heart failure,bleeding caused by coagulation,and infective endocarditis. Irregular monitoring of coagulation caused higher incidence of coagulation related complications.5.The active support of the cardiac function after operation,the prevention and cure of arrhythmia,regular follow-up could help lower the incidence of the late complications and improve the late efficacy.