Recent developments and controversies in transcatheter aortic valve implantation

Interventional cardiology has been revolutionised by transcatheter aortic valve implantation (TAVI), which has become established as the benchmark treatment for severe aortic stenosis in patients at high risk for surgical aortic valve replacement (AVR). Increased procedural familiarity and progression in device technology has enabled improvements to be made in complication rates, which have led to a commensurate expansion in the use of TAVI; it is now a viable alternative to AVR in patients at intermediate surgical risk, and has been used in cohorts such as those with bicuspid aortic valves or pure, severe aortic regurgitation. Given the rapid expansion in the use of TAVI, including cohorts of younger patients with fewer co‐morbidities, attention must be paid to further reducing remaining complications, such as cardiac tamponade or stroke. To this end, novel techniques and devices have been devised and trialled, with varying levels of success. Furthermore, significant work has gone into refining the technique with exploration of alternative imaging modalities, as well as alternative access routes to provide greater options for patients with challenging vascular anatomy. Whilst significant progress has been made with TAVI, areas of uncertainty remain such as the management of concomitant coronary artery disease and the optimum post‐procedure antiplatelet regimen. As such, research in this field continues apace, and is likely to continue as use of TAVI becomes more widespread. This review provides a summary of the existing evidence, as well as an overview of recent developments and contentious issues in the field of TAVI.     

Acute kidney injury following transcatheter aortic valve implantation: incidence,predictors and clinical outcome

Background

Limited data exist on renal complications of transcatheter aortic valve implantation (TAVI) within a comprehensive program using different valves with transfemoral, transapical, and trans-subclavian approach.

Methods

Prospective single-center registry of 102 consecutive patients undergoing TAVI using both approved bioprostheses and different access routes. The main objective was to assess the incidence, predictors and the clinical impact of acute kidney injury (AKI). AKI was defined according to the valve academic research consortium (VARC) indications.

Results

Mean age was 83.7 ± 5.3 years, logistic EuroSCORE 22.6 ± 12.4%, and STS score 8.2 ± 4.1%. Chronic kidney disease at baseline was present in 87.3%. Periprocedural AKI developed in 42 patients (41.7%): 32.4% stage 1, 4.9% stage 2 and 3.9% stage 3. The incidence of AKI was 66.7% in transapical, 30.3% in transfemoral, and 50% in trans-subclavian procedures. The only independent predictor of AKI was transapical access, with a hazard ratio (HR) between 4.57 and 5.18 based on the model used. Cumulative 1-year survival was 88.2%. At Cox regression analysis, the only independent predictor of 30-day mortality was diabetes mellitus (HR 7.05, 95% CI 1.07–46.32; p = 0.042), whilst the independent predictors of 1-year death were baseline glomerular filtration rate < 30 mL/min (HR 5.74, 95% CI 1.42–23.26; p = 0.014) and post-procedural AKI 3 (HR 8.59, 95% CI 1.61–45.86, p = 0.012).

Conclusions

TAVI is associated with a high incidence of AKI. Although in the majority of the cases AKI is of mild entity and reversible, AKI 3 holds a strong negative impact on 1-year survival. The incidence of AKI is higher with transapical access.     

Outcome of transcatheter aortic valve implantation in high risk patients with severe aortic stenosis

Aim

To assess outcome of TAVI in high risk patients with severe symptomatic aortic stenosis.

Effect of transcatheter aortic valve implantation on QT dispersion in patients with aortic stenosis

Background QT dispersion （QTd） is a predictor of ventricular arrhythmia. Ventricular arrhythmia is an important factor influencing morbidity and mortality in patients with aortic stenosis. Surgical aortic valve replacement reduced the QTd in this patients group. However, the effect of transcatheter aortic valve implantation （TAVI） on QTd in patients with aortic stenosis is unknown. The aim of this study was to investigate the effect of TAVI on QTd in patients with aortic stenosis. Methods Patients with severe aortic stenosis, who were not candi-dates for surgical aortic valve replacement due to contraindications or high surgical risk, were included in the study. All patients underwent electrocardiographic and echocardiographic evaluation before, and at the 6th month after TAVI, computed QTd and left ventricular mass index （LVMI）. Results A total 30 patients were admitted to the study （mean age 83.2 ± 1.0 years, female 21 and male 9, mean valve area 0.7 ± 3 mm2）. Edwards SAPIEN heart valves, 23 mm （21 patients） and 26 mm （9 patients）, by the transfemoral approach were used in the TAVI procedures. All TAVI procedures were successful. Both QTd and LVMI at the 6th month after TAVI were significantly reduced com-pared with baseline values of QTd and LVMI before TAVI （73.8 ± 4 ms vs. 68 ± 2 ms, P=0.001 and 198 ± 51 g/m2 vs. 184 ± 40 g/m2, P=0.04, respectively）. There was a significant correlation between QTd and LVMI （r=0.646, P〈0.001）. Conclusions QTd, which malign ventricular arrhythmia marker, and LVMI were significantly reduced after TAVI procedure. TAVI may decrease the possibility of ventricu-lar arrhythmia in patients with aortic stenosis.     

Validation of methods for effective orifice area measurement of prosthetic valves by two-dimensional and Doppler echocardiography following transcatheter self-expanding aortic valve implantation

BackgroundThe effective orifice area (EOA) is utilized to characterize the hemodynamic performance of the transcatheter heart valve (THV). However, there is no consensus on EOA measurement of self-expanding THV. We aimed to compare two echocardiographic methods for EOA measurement following transcatheter self-expanding aortic valve implantation.MethodsEOA was calculated according to the continuity equation. Two methods were constructed. In Method 1 and Method 2, the left ventricular outflow tract diameter (LVOTd) was measured at the entry of the prosthesis (from trailing-to-leading edge) and proximal to the prosthetic valve leaflets (from trailing-to- leading edge), respectively. The velocity-time integral (VTI) of the LVOT (VTI_LVOT) was recorded by pulsed-wave Doppler (PW) from apical windows. The region of the PW sampling should match that of the LVOTd measurement with precise localization. The mean transvalvular pressure gradient (MG) and VTI of THV was measured by Continuous wave Doppler.ResultsA total of 113 consecutive patients were recruited. The mean age was 77.2 ± 5.5 years, and 72 patients (63.7%) were male. EOA₁ with the use of Method 1 was larger than EOA₂ (1.56 ± 0.39 cm² vs. 1.48 ± 0.41 cm², P = 0.001). MG correlated better with the indexed EOA₁ (EOAI₁) (r = -0.701, P < 0.001) than EOAI₂ (r = -0.645, P < 0.001). According to EOAI (EOAI ≤ 0.65 cm²/m², respectively), the proportion of sever prosthesis-patient mismatch with the use of EOA₁ was lower than EOA₂ (12.4% vs. 21.2%, P < 0.05). Compared with EOA₂, EOA₁ had lower interobserver and intra-observer variability (intra: 0.5% ± 17% vs. 3.8% ± 22%, P < 0.001; inter: 1.0% ± 9% vs. 3.5% ± 11%, P < 0.001).ConclusionsFor transcatheter self-expanding valve EOA measurement, LVOTd should be measured in the entry of the prosthesis stent (from trailing-to-leading edge), and VTI_LVOT should match that of the LVOTd measurement with precise localization.     

Development of transcatheter aortic valve implantation (TAVI): A heart-warming adventure

The development of transcatheter aortic valve implantation (TAVI) spearheaded by our group has been a great adventure since we validated the concept in the early 1990s in aortic stenosis (AS) postmortem studies. We first tested prototypes in animal models before performing the daring first-in-man implantation in 2002. Prospective compassionate use series followed, accompanied by ongoing technological innovation of devices and of delivery systems. High surgical risk patients were enrolled in feasibility studies, which led to the Conformité Européenne (CE) mark being granted in 2007. Data from post-marketing registries involving thousands of patients have shown remarkable results and increasingly smaller complication rates, as a result of growing experience and improved technology. Survival and quality of life results from the landmark randomized PARTNER Edwards SAPIEN study have confirmed the important place of TAVI in non-operable and high surgical risk patients. To date, more than 50,000 patients have benefited from TAVI worldwide. TAVI is now recommended in the European Society of Cardiology (ESC), the European Association for Cardio-Thoracic Surgery (EACTS) guidelines, and by the Food and Drug Administration in the United States for the treatment of AS patients who are not suitable or at high risk for surgery, as assessed by a multidisciplinary heart team, and in whom a less invasive approach is favored. Multidisciplinary heart teams are critical in patient selection and in successful procedures. In future, TAVI may be extended to use in lower risk patients, although further clinical investigation is necessary. Just over 10 years after the first-in-man case, TAVI has quickly become an established AS treatment option.     

Advanced age and the clinical outcomes of transcatheter aortic valve implan-tation

Aortic valve stenosis （AS） is common in the elderly. Although surgical replacement of the valve has been the gold standard of management, many patients have been excluded from surgery because they were very old, frail, or had co-morbidities that increased operative risks. In the last decade, transcatheter aortic valve implantation （TAVI） has emerged as a new treatment option suitable for these patients. This article reviews the available literature on the role of TAVI in elderly patients with severe aortic stenosis. Published studies showed that elderly individuals who underwent TAVI experienced better in-hospital recovery, and similar short and mid-term mortality compared to those underwent surgical treatment of AS. However, long-term outcomes of TAVI in elderly patients are still unknown. The available data in the literature on the ef-fect of advanced age on clinical outcomes of TAVI are limited, but the data that are available suggest that TAVI is a beneficial and tolerable procedure in very old patients. Some of the expected complications after TAVI are reported more in the oldest patients such as vascular in-jures. Other complications were comparable in TAVI patients regardless of their age group. However, very old patients may need closer monitoring to avoid further morbidities and mortality.     

Future perspectives in transcatheter aortic valve implantation

Transcatheter aortic valve replacement (TAVR) constitutes a relatively new treatment option for the patients with severe symptomatic aortic stenosis. Evidence from registries and randomized control trials has underscored the value of this treatment in inoperable and high risk populations, while new developments in valve technology and TAVR enabling devices have reduced the risk of complications, simplified the procedure, and broadened the applications of this therapy. The initial promising clinical results and the potential of an effective less invasive treatment of aortic stenosis has not only created high expectations but also the need to address the pitfalls of TAVR technology. The evolving knowledge concerning the groups of patients who would benefit from this treatment, the limited long term follow-up data, the concerns about devices' long term durability, and the severity of complications remain important caveats which restrict the widespread clinical adoption of TAVR. The aim of this review article is to present the recent advances, highlight the limitations of TAVR technology, and discuss the future perspectives in this rapidly evolving field.     

Updates on transcatheter aortic valve replacement: Techniques,complications, outcome,and prognosis

Transcatheter aortic valve replacement (TAVR) initially emerged as a therapeutic option for high-risk patients with severe aortic stenosis. Advancement in technologies since the first era of TAVRs, experience from previous obstacles, and lessons learned from complications have allowed the evolution of this procedure to the current state. This review focuses on the updates on the most current devices, complications, and outcomes of TAVR.     

Clinical and prognostic implications of atrial fibrillation in patients undergoing transcatheter aortic valve implantation

AIM: To study a cohort of consecutive patients under-going transcatheter aortic valve implantation (TAVI) and compare the outcomes of atrial fibrillation (AF) patients vs patients in sinus rhythm (SR). METHODS: All consecutive patients undergoing TAVI in our hospital were included. The AF group comprised patients in AF at the time of TAVI or with history of AF, and were compared with the SR group. Procedural, echocardiographic and follow-up variables were compared. Likewise, the CHA 2 DS 2-VASC stroke risk score and HAS-BLED bleeding risk score and antithrombotic treatment at discharge in AF patients were compared with that in SR patients. RESULTS: From a total of 34 patients undergoing TAVI, 17 (50%) were allocated to the AF group, of whom 15 (88%) were under chronic oral anticoagulation. Patients in the AF group were similar to those in the SR group except for a trend (P = 0.07) for a higher logistic EuroSCORE (28% vs 19%), and a higher prevalence of hypertension (82% vs 53%) and chronic renal failure (17% vs 0%). Risk of both stroke and bleeding was high in the AF group (mean CHA 2 DS 2-VASC 4.3, mean HAS-BLED 2.9). In the AF group, treatment at discharge included chronic oral anticoagulation in all except one case, and in association with an antiplatelet drug in 57% of patients. During a mean follow-up of 11 mo (maximum 32), there were only two strokes, none of them during the peri-procedural period: one in the AF group at 30 mo and one in the SR group at 3 mo. There were no statistical differences in procedural success, and clinical outcome (survival at 1 year 81% vs 74% in AF and SR groups, respectively, P = NS). CONCLUSION: Patients in AF undergoing TAVI show a trend to a higher surgical risk. However, in our cohort, patients in AF did not have a higher stroke rate compared to the SR group, and the prognosis was similar in both groups.     

经导管主动脉瓣置入手术在主动脉瓣狭窄合并二尖瓣反流治疗中的疗效分析

目的:分析经导管主动脉瓣置入术在主动脉瓣狭窄合并二尖瓣反流(MR)的疗效。方法:选取我院就诊的主动脉瓣狭窄合并MR流患者31例,所有患者均行经导管主动脉瓣置入术,按照患者的MR流严重程度分为A组(轻度)和B组(中度、重度)。比较两组的并发症发生率、术后1个月的LVEF、LVEDD、MR和NYHA分级,比较两组在术后1个月、3个月时的死亡率和生活质量。结果:两组的各并发症发生率差异无统计学意义(P>0.05);A组在术后1个月时的LVEF和日常生活能力量表(ADL)评分均明显高于B组(P<0.05);A组在术后1个月时的死亡率、LVEDD、MR和NYHA分级明显低于B组(P<0.05);两组患者在术后3个月时的死亡率和ADL评分均差异无统计学意义(P>0.05)。结论:经导管主动脉瓣置入手术可用于主动脉瓣狭窄合并不同程度MR流患者的治疗中,反流的严重程度对患者远期死亡率和生活质量恢复的影响较小。     

心房颤动患者经导管主动脉瓣植入术后1年随访结果

目的:探讨经导管主动脉瓣植入（TAVI）术前合并心房颤动（房颤）是否会对患者的预后产生影响。方法:本研究为单中心回顾性研究。入选2016年5月至2020年11月于北部战区总医院住院并成功接受TAVI治疗且顺利出院的重度主动脉瓣狭窄患者115例。根据入选患者是否合并房颤将其分为房颤组（21例）及非房颤组（94例）。随访纳...     

经导管主动脉瓣置换术对主动脉瓣狭窄患者肾功能的影响

目的探讨经导管主动脉瓣置换术(TAVR)对主动脉瓣狭窄患者术后肾功能的影响。方法本研究为单中心回顾性研究。连续入选2014年10月至2019年10月在复旦大学附属中山医院行TAVR治疗的主动脉瓣狭窄患者。依据术前1 d肾小球滤过率(eGFR)将纳入患者分为4组:>90 ml·min^-1·1.73m^-2组、>60~90 ml·min^-1·1.73m^-2组、>30~60 ml·min^-1·1.73m^-2组和≤30 ml·min^-1·1.73m^-2组。术后72 h再次检测eGFR,按照术后肾功能变化将患者分为急性肾功能恢复(AKR)组、急性肾脏损伤(AKI)组和肾功能无变化组。其中AKR定义为TAVR术后72 h的eGFR值增加>基线值的25%,AKI定义为TAVR术后72 h的eGFR值降低>基线值的25%。比较各组的相关临床资料,并采用多因素logistic回归分析TAVR术后肾功能变化的影响因素。结果本研究共纳入217例因主动脉瓣狭窄行TAVR治疗的患者,年龄(76.7±7.4)岁,其中女性86例,胸外科医师学会评分为(9.5±5.8)分。>90 ml·min^-1·1.73m^-2组(n=19)、>60~90 ml·min^-1·1.73m^-2组(n=116)、>30~60 ml·min^-1·1.73m^-2组(n=70)和≤30 ml·min^-1·1.73m^-2组(n=12)术后达AKR者所占比例分别为0、30.2%(35/116)、58.6%(41/70)和75.0%(9/12);共3例(1.4%)患者发生AKI,其中>30~60 ml·min^-1·1.73m^-2组2例,>60~90 ml·min^-1·1.73m^-2组1例。eGFR<60 ml·min^-1·1.73m^-2患者中AKI发生率为2.4%(2/82)。纳入的217例患者中,AKR组85例(39.2%)、AKI组3例(1.4%)、肾功能无变化组129例(59.4%)。3组的体重指数(BMI)、术前左心室舒张末期内径(LVEDD)和术前eGFR分布差异有统计学意义(P均<0.05)。多因素logistic回归分析显示,BMI(OR=5.54,95%CI 1.04~29.58,P=0.045)、术前LVEDD(OR=1.22,95%CI 1.09~1.38,P=0.001)及术前eGFR(OR=2.23,95%CI 2.04~2.55,P=0.004)是术后非AKR的危险因素。结论TAVR术后绝大多数患者表现为肾功能不变或者改善,TAVR术后肾功能的变化与BMI及术前LVDD、eGFR相关。     

Evolution of non-invasive myocardial work variables after transcatheter aortic valve implantation in patients with severe aortic stenosis

IntroductionGuidelines recommend aortic valve replacement in patients with severe aortic stenosis who present with symptoms or left ventricular ejection fraction < 50%, both conditions representing a late stage of the disease. Whereas global longitudinal strain is load dependent, but interesting for assessing prognosis, myocardial work has emerged.AimTo evaluate acute changes in myocardial work occurring in patients undergoing transcatheter aortic valve implantation (TAVI).MethodsPatients who underwent TAVI were evaluated before and after by echocardiography. Complete echocardiographies were considered. Myocardial work indices (global work index, global constructive work, global work efficiency, global wasted work) were calculated integrating mean transaortic pressure gradient and brachial cuff systolic pressure.ResultsOne hundred and twenty-five patients underwent successful TAVI, with a significant decrease in mean transaortic gradient (from 52.5 ± 16.1 to 12.2 ± 5.0; P < 0.0001). There was no significant change in left ventricular ejection fraction after TAVI. Myocardial work data after TAVI showed a significant reduction in global work index (1389 ± 537 vs. 2014 ± 714; P < 0.0001), global constructive work (1693 ± 543 vs. 2379 ± 761; P < 0.0001) and global work efficiency (85.0 ± 7.06 vs. 87.1 ± 5.98; P = 0.0034). The decrease in global work index and global constructive work after TAVI was homogeneous among different subgroups, based on global longitudinal strain, left ventricular ejection fraction and New York Heart Association status before TAVI. We observed a significant association between global work index and global constructive work before TAVI, and global longitudinal strain degradation after TAVI.ConclusionsMyocardial work variables show promising potential in best understanding the left ventricular myocardial consequences of aortic stenosis and its correction. Given their ability to discriminate between New York Heart Association status and global longitudinal strain evolution, we can hypothesize about their clinical value.     

Oversizing, undersizing or just the right sizing for TAVI patients?

Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation (TAVI) procedures remain an issue. Benefit of oversizing strategies to prevent them isn’t well established. We compared different level of oversizing in our cohort of consecutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. Methods From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT (MSCT) and the procedures were achieved using Edwards Sapien^? or Corevalve devices^?. Retrospectively, according to pre-procedural MSCT and the valve size, patients were classified into three groups: normal, moderate and severe oversizing; depending on the ratio between the prosthesis area and the annulus area indexed and measured on MSCT. Main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium (VARC-2) endpoints. Results Two hundred and sixty eight patients had a MSCT and underwent TAVI procedure, with mainly Corevalve^?. While all-cause and cardiovascular mortality rates were similar in all groups, post-procedural new pacemaker (PM) implantation rate was significantly higher in the severe oversizing group (P = 0.03), while we observed more in-hospital congestive heart-failure (P = 0.02) in the normal sizing group. There was a trend toward more moderate to severe aortic regurgitation (AR) in the normal sizing group (P = 0.07). Conclusions Despite a higher rate of PM implantation, oversizing based on this ratio reduces aortic leak with lower rates of post-procedural complications and a similar mid-term survival.     

Transaortic transcatheter aortic valve implantation within a previous bioprosthetic aortic valve replacement

This report documents the first reported case of transaortic transcatheter aortic valve implantation (TAVI) using the CoreValve ReValving system (Medtronic CoreValve System, Luxembourg), within a previous bioprosthetic aortic valve replacement. TAVI has become a recognized percutaneous treatment for patients with severe native or bioprosthetic aortic valve stenosis. However, as the number of patients screened for TAVI increases, a number of patients are found with absolutely no option for peripheral arterial access, either from the femoral or subclavian routes. Transaortic CoreValve placement offers an alternate minimally invasive hybrid surgical/interventional technique when peripheral access is not possible. A CoreValve prosthesis was implanted via the transaortic route in an 81‐year‐old woman with severe bioprosthetic aortic valve stenosis (21 mm Mitroflow pericardial valve, peak instantaneous gradient of 99 mmHg, effective valve orifice area (EOA) of 0.3 cm², as ilio‐femoral and left subclavian angiography revealed small calibre vessels (<6 mm). Access was achieved via a mini thoracotomy via the left anterior second intercostal space. The procedure went without complication. Post procedure the patient was transferred directly to the Cardiac Care Unit for recuperation. Post procedure echocardiography showed that the TAVI was well positioned with no para‐valvular leak and a reduction in peak instantaneous gradient to 30 mmHg and an increase in EOA to 1.5 cm². She was discharged on the third post‐procedural day in sinus rhythm with a narrow QRS complex. CoreValve implantation within previous surgical bioprosthesis is now an established treatment. The transaortic approach to transcatheter implantation is a promising recent development, when due to anatomical reasons, transfemoral or subclavian TAVI is not feasible. © 2011 Wiley‐Liss, Inc.     

Transcatheter aortic valve implantation (TAVI): Valve design and evolution

The efficacy of transcatheter aortic valve implantation (TAVI) in high surgical risk and inoperable patients with severe aortic stenosis (AS) is rapidly gaining credibility with an ever-expanding body of supporting evidence. The potential of TAVI to be a treatment option for a significant cohort of patients with aortic stenosis has fuelled a drive for the optimum device and resulted in exponential advances in the technology with a focus on adverse event minimization and procedural simplification. Consequently, a plethora of new transcatheter valve choices are now available for clinical study or in the pipeline. The evaluation of past, current and emerging devices allows for an appreciation of the design considerations involved in this process and an insight to the future direction of the technology.