Clinical Reserch Of Bicuspid Aortic Valve Aortopathy And Evaluation Of Bicuspid Aortic Valve Repair

Bicuspid aortic valve(BAV)is the most common congenital cardiac abnormality affecting approximately 1%to 2%of the population based on autopsy studie.Patients with BAV have a higher risk of serious adverse clinical outcomes throughout their lives.15-71%will develop severe aortic stenosis,30-47%will develop aortic valve insufficiency,and 3070%will develop ascending aortic aneurysm,2-3%will develop infective endocarditis.In the United States,BAV accounts for about 40%of patients undergoing aortic valve surgery,and about 35%of patients undergoing aortic valve surgery in Fuwai Hospital.Therefore,BAV and its related complications cause very serious medical and social burdens.This study focused on BAV valvular malformation and carried out a clinical followup study on the characteristics of the BAV and the long-term prognosis of the related aortic aortopathy.BAV aortopathy named dilatation of any or all segments of the proximal aorta from the aortic root to the aortic arch.It has been a hot spot of international and domestic research in the past 20 years.The following two hypotheses have been proposed as an explanation for this significant association:aortic dilation that occurs due to hemodynamic burdens caused by aortic stenosis(AS)or aortic insufficiency(AI)associated with BAV.The other is congenital aortic fragility.Many studies have shown that there are many types of BAV aortopathy.In order to describe the characteristics of BAV aortopathy,a variety of classification systems have been proposed to describe it,but none of them has been widely accepted and adopted.The first part of this study is based on the accurate BAV anatomical classification according to the operation insight.It is proposed to combine objective cluster analysis and subjective classification to describe the characteristics of BAV aortopathy.Assess whether there is an association between BAV valve malformation and aortopathy and the specific form of association.At present,there is a controversy about the timing of intervention for BAV aortopathy.Some researchers believe that BAV aortopathy is genetically related.In order to avoid the risk of aortic dissection,active intervention is required.The other researchers believe that the risk of aortic dissection in BAV patients is similar to that of the population and does not require active intervention.Adopting active strategies will result in increased surgical risks and waste of medical resources.Adopting conservative strategies may delay the patient's treatment timing and expose patients to greater risks of aneurysm and dissection.Therefore,in the second part of this study,patients underwent isolated aortic valve replacement were grouped according to valve morphology,and long-term follow-up studies were conducted to observe changes in aortic diameter and aortic events.The purpose is to find the best timing of surgery for BAV aortopathy.For BAV valvular disease,the 2020 AHA valvular disease guidelines recommend artificial valve replacement,but the bleeding and thrombosis associated with valve replacement and the complications of artificial valve failure caused by valve replacement affect the long-term quality of life and survival of patients.In recent years,for patients with aortic regurgitation,especially for patients with secondary regurgitation caused by root expansion,more and more studies have shown that valve repair is significantly better than valve replacement.However,it is still controversial whether it is feasible to perform aortic repair in patients with BAV combined with simple insufficiency.Therefore,the third part of this study adopts a prospective cohort study method to explore the effectiveness and safety of aortic valve repair in the BAV with aortic regurgitation patients,and establish the preoperative evaluation strategy,surgical strategy and reinsufficiency risk factors of for BAV repair.The specific four parts of the research on the bicuspid aortic valve are summarized as follows:Part1:Characteristics of Bicuspid Aortic Valve Aortopathy and the Association with Valvular Phenotype and DysfunctionObjectives:We sought to summarize the characteristics of bicuspid aortic valve(BAV)aortopathy and analyze the association between aortopathy and BAV phenotype and patterns of valvular dysfunction.Methods:The study cohort included 191 subjects who underwent the first aortic valve replacement in Fuwai hospital from June 2017 to March 2018.All patients underwent multidetector computed tomography(MDCT)and echocardiography before the operation,excluding patients with aortic coarctation.The BAV anatomic phenotype was classified during operation.The characteristics of BAV aortopathy were analyzed by cluster and artificial analysis,BAV phenotype was divided into two types according to the direction of valve opening:BAV-AP and BAV-LR.Results:The average age was 53.9±12.5 years old,with 74.9%of males and 81.7%of patients with aortic dilatation.Four distinct BAV aortopathy phenotype were identified:common type(n=70;36.6%),with aorta no dilation or mild dilation;root type(24;12.6%),with predominant dilatation of aortic sinus;ascending type(72;37.7%),with predominant dilatation of ascending aorta;arch type(25;13.1%),with predominant dilatation of aortic arch dilatation.The root type was mainly young patients,while the arch type was mainly elderly patients,the difference was statistically significant(P<0.05).BAV-AP and aortic insufficiency were most prevalent in root type,while BAV-LR and aortic stenosis were most prevalent in arch type,the difference was statistically significant(P<0.05).111 patients(58.1%)underwent aortic surgery,and the coincidence rate of BAV aortopathy phenotype and aortic surgery was 80.6%.Conclusions:According to the location of aortic dilation,BAV aortopathy can be divided into four types.There is an association between BAV aortopathy and valvular phenotype and dysfunction.Part2:Outcomes after isolated aortic valve replacement in patients with bicuspid versus tricuspid aortic valveObjectives:To compare the outcomes in patients undergoing isolated aortic valve replacement with bicuspid(BAV)versus tricuspid aortic valves(TAV).Methods:A total of 1204 consecutive patients(BAV,n=454;TAV,n=750)underwent isolated aortic valve replacement(AVR)between 2002 and 2009 at a single institution.Adverse aortic events were defined as the occurrence of aortic dissection or the ascending aorta diameter greater than 50 mm or sudden death during follow-up.Propensity matching yielded 333 patient pairs.Results:Follow-up was obtained on 1156 patients.The mean length of follow up was 10.4±3.9 years.A total of 155(13.4%)patients died,and adverse aortic events occurred in 44(3.8%)patients.Postoperative survival rates(log-rank,P=0.307)and freedom from adverse aortic events(log-rank,P=0.197)were not significantly different between the two groups.After propensity score matching,the 15-year survivals was 75.7%in the BAV group and 83.9%in the TAV group(hazard ratio,1.4;P=0.147).The 15-year freedom from adverse aortic events was 90.6%in the BAV group and 90.7%in the TAV group(hazard ratio,1.2;P=0.578).In the isolated aortic regurgitation subgroup,the rate of adverse aortic events was significantly higher in the BAV group than in the TAV group(P=0.021).Conclusions:The risk of adverse aortic events after isolated AVR was low in both BAV and TAV patients.For BAV,complicated with isolated aortic insufficiency,an aggressive aortopathy intervention strategy may be adopted to prevent late adverse aortic events.Part3:Bicuspid aortic valve repairBackground:The application of aortic valve repair in patients with bicuspid aortic valve(BAV)is controversial.This study compares the efficacy of aortic valve repair in patients with BAV and tricuspid aortic valve(TAV)using a prospective cohort study method to explore the effectiveness and safety of aortic valve repair in the treatment of patients with BAV insufficiency.Methods:This study included patients who completed aortic valve repair at Fuwai Hospital from January 2017 to June 2020.Collect demographic information,imaging data and perioperative data of the patients.Standard preoperative evaluation,intraoperative evaluation,valve repair and postoperative follow-up strategies were used to compare the difference between the survival rate of BAV and TAV patients after valve repair and the rate of aortic regurgitation.Results:A total of 177 patients were enrolled in this study,of which 54 were BAV,accounting for 30.5%.One died during peri operation(TAV),with a total mortality rate of 0.6%.The proportion of males in the BAV group was 96.3%,which was significantly higher than that of TAV patients(P=0.026).The geometric height of the valve leaflets in BAV patients was lower than that in TAV patients,but the diameter of the aortic valve annulus was larger,and the diameters of the aortic sinus,sinus tube junction and ascending aorta were significantly smaller than those in the TAV group.The median follow-up time was 12(7-18.75)months,and the follow-up rate was 100%.There was no significant difference in the early survival rate between the two groups of patients(P=0.52).Eleven patients had moderate or above aortic regurgitation,5 in the BAV group and 7 in the TAV group.There was no statistically significant difference between the two groups(P=0.224).Three patients had moderate to severe aortic valve regurgitation,2 in the BAV group and 1 in the TAV group.There was no statistically significant difference between the two groups(P=0.105).In 41 cases of BAV annulus repair,the postoperative avoidance of moderate to severe aortic valve regurgitation was significantly better than that of patients with unrepaired annulus(P = 0.012).Conclusion:This study found that after rigorous preoperative and intraoperative evaluation,the aortic valve repair technique can be safely and effectively applied to patients with BAV insufficiency,and the early results are satisfactory.Different surgical strategies are adopted for different characteristics of BAV lesions,and a combined strategy of valve leaflet repair,valve annulus repair and aortic repair is required.Annulus repair can reduce the risk of recurrent aortic regurgitation after BAV repair.Part4:Research progress of bicuspid aortic valve aortopathyBicuspid aortic valve is the most common congenital heart disease.About 40-50%of patients assosiated ascending aortic dilatation disease,which is called bicuspid aortopathy.Although the research on the genetics,pathology,molecular,hemodynamics and morphology of this disease has been deeply carried out in recent years,the disease is still not fully understood.Lack of knowledge of the disease directly leads to confusion in the timing of surgical intervention.This paper reviews the latest research progress in this field in recent years,systematically expounds the pathogenesis of bicuspid aortic valve malformation combined with aortic disease and indications for surgical intervention,in order to expand the understanding of the disease.