Characteristrics And Prognosis Of Patients With Small Left Ventricular Size Undergoing Transcatheter Aortic Valve Replacement And Influence On Left Ventricular Remodeling

Part 1:Characteristics of patients with Small Left Ventricular Size undergoing Transcatheter Aortic Valve ReplacementObjectives:Left ventricular hypertrophy(LVH)caused by aortic stenosis is a complex pathophysiological process with changes in cardiac chamber size.Transcatheter balloon aortic valvuloplasty in patients with small left ventricular size is prone to high-risk complications,which seriously affects the prognosis of the procedure.No data investigate the small left ventricular size patients in transcatheter aortic valve replacement(TAVR).Therefore,the purpose of this study was to explore the differences of clinical baseline characteristics.blood routine and imaging characteristics of patients with small left ventricular size in TAVR,and to provide help for the preoperative carefully evaluation of these patientsMethods:Patients were consecutively enrolled from January 1,2015 to December 31,2018 in Cardiovascular Center of the Second Affiliated Hospital of Zhejiang University School of Medicine.Preoperative data of clinical baseline characteristics,blood analysis,computed tomographic angiography(CTA)and cardiac Doppler Echocardiography were recorded.Patients were divided into two groups according to preoperative left ventricular end-diastolic diameter(LVEDD<4.0cm)Results:306 patients were enrolled.In these included patients,30 patients(9.8%)were divided into small left ventricle(LV)group and 276 patients(90.2%)were divided into non-small LV group.Majority of patients in small LV group were older[80 years(IQR:74-83)vs.77 years(IQR:72-81),p=0.044],female(86.7%vs.38.4%,p=0.000)with lower body surface area(1.50±0.14 m2 vs.1.64±0.16 m2,p=0.000).Patients in small LV group had higher prevalence of syncope symptom(23.3%vs.8.7%,p=0.027).Echocardiographic data showed these small LV size patients had smaller effective orifice area[0.46cm2(IQR:0.42-0.60)vs.0.58cm2(IQR:0.44-0.74),p=0.013],higher LV ejection fraction[62.9%(IQR:56.6-69.8)vs.56.0%(IQR:41.2-63.2),p=0.000]and smaller left atrial size[3.62cm(IQR:3.19-4.16)vs.4.28cm(IQR:3.87-4.74),p=0.000].Patients in small LV group were nearly all pure aortic stenosis patients(90.0%vs.61.6%,p=0.002)and rate of moderate and severe regurgitation was lower in small LV group when compared to non-small LV group(6.7%vs.31.2%and 3.3%vs.8.3%respectively,p=0.006).Between the small and non-small LV group,significant differences of computed tomographic data were found in average annulus diameter[22.3cm(IQR:21.3-23.5)vs.24.5cm(IQR:23.0-26.2),p=0.000],area derived annulus diameter(22.3± 1.8 mm vs.24.6±2.5 mm,p=0·000)and perimeter derived annulus diameter(22.9± 1.7 mm vs.25.0±2.4 mm,p=0.000).Conclusion:Patients with small LV size were more likely the older,female patients with lower body surface area,complained with more symptom of syncope.There patients could be found with higher LV ejection fraction and smaller left atrial size.Pure aortic stenosis were more common in small LV patients and more regurgitation in non-small LV patients.Smaller annulus size were found both in echocardiography and computed tomography.Part 2:Prognosis of patients with Small Left Ventricular Size undergoing Transcatheter Aortic Valve Replacement and influence on Left Ventricular RemodelingObjectives:Left ventricular pressure overload caused by aortic stenosis can lead to left ventricular(LV)remodeling and left ventricular hypertrophy.According to the left ventricular mass index and relative wall thickness,these pathophysiological process can be categorized as concentric remodeling,concentric hypertrophy and eccentric hypertrophy.One part of the patents with aortic stenosis had small LV chamber size with thickened LV wall.There had been reported that these small LV size and thickened wall patients had more severe complication after transcatheter balloon aortic valvuloplasty.However,there is no related studies.Therefore,we aim to investigate the related complication of small LV patients undergoing transcatheter aortic valve replacement(TAVR)and its influence on LV remodeling.Methods:Patients undergoing TAVR were consecutively enrolled from January 1,2015 to December 31,2018 in Cardiovascular Center of the Second Affiliated Hospital of Zhejiang University School of Medicine.Patients were divided into two groups according to preoperative left ventricular end-diastolic diameter(patients with LVEDD<4.0cm divided into small LV group).Procedural detail,peri-procedural complication,and data of follow-up were compared between these two group.Moreover,LV modeling according the echocardiographic data in 1 year follow-up were analyzed.Results:Patients in small LV group received smaller size valve(24.6±1.7 vs.26.4±2.5,p=0.000)with more proportion of local anesthesia(29.3%vs.76.8%,p=0.037).the small LV size was associated with higher immediate procedural mortality(6.7%vs.0.7%,p=0.049)and vascular complication(23.3%vs.4.0%,p=0.000).Before pre-discharge,in-hospital mortality tended to be higher(6.7%vs.1.1%,p=0.077)in small LV group.Smaller effective orifice area(1.40±0.34cm2 vs.1.55±0.29 cm2,p=0.014),higher LV ejection fraction(64.9±4.3%vs.58.3±10.5%,p=0.000)and smaller atrial size(3.49±0.88 cm vs.4.13±0.62 cm,p=0.002)still found in small LV group at 30d follow-up.Local anesthesia was an independent protect factor(OR 0.048,95%CI 0.002-0.991,p=0.049),while the small LV increased the immediate procedural mortality(OR 54.639,95%CI 1.563-1910.650,p=0.027).There were significant differences of the LV mass index(LVMi)between two groups in baseline(112.89±28.80 vs.165.96±43.21,p=0.000),pre-discharge(117.44±31.61 vs.154.36±41.92,p=0.000),30 day follow-up(106.19±29.17 vs.140.01±39.09,p = 0.000)until 6 month follow-up(107.45±53.94 vs.128.32±38.69,p=0.452)and 1 year after TAVR(97.76±36.92 vs.115.40±34.74,p=0.387).In small LV group,LVMi did not change significantly with time after TAVR(p>0.05),while in non-small LV group,LVMi changed with time significantly(p<0.05).Conclusion:Compared to non-small LV size patients,patients with small chamber size had worse peri-procedural outcomes with higher immediate procedural mortality and vascular complication.In 30 day follow-up,the LV geometry did not recover.Moreover,the difference of LVMi between two group didn't differ when 6 month after TAVR.