The Self-Expanding Symetis Acurate Does Not Increase Cerebral Microembolic Load When Compared to the Balloon-Expandable Edwards Sapien Prosthesis: A Transcranial Doppler Study in Patients Undergoing Transapical Aortic Valve Implantation

Objectives The aim of this study was to quantify potential differences in count, frequency and pattern of high-intensity transient signals (HITS) during transapical transcatheter aortic valve implantation (TA-TAVI), by comparing the Symetis Acurate TA (SA) with the balloon-expandable Edwards Sapien XT (ES) system. Background Recently, the Symetis Acurate TA revalving system has been introduced for TA-TAVI. The Symetis Acurate TA aortic bioprosthesis is self-expanding and is deployed by a specific two-step implantation technique. Whether this novel method increases the load of intraprocedural emboli, detected by transcranial Doppler ultrasound (TCD) as HITS, or not is not clear. Methods Twenty-two patients (n = 11 in each study arm, median logistic EuroScore 20%, median STS score 7%) displayed continuous TCD signals of good quality throughout the entire TA-TAVI procedure and were included in the final analysis. Data are presented as median with interquartile ranges. Results No significant differences were detected in total procedural or interval-related HITS load (SA: 303 [200; 594], ES: 499 [285; 941]; p = 0.16). With both devices, HITS peaked during prosthesis deployment (PD), whereas significantly fewer HITS occurred during instrumentation (SA: p = 0.002; ES: <0.001) or post-implantation PI (SA: p = 0.007; ES: <0.001). PD-associated HITS amounted to almost half of the total HITS load. One patient suffered new disabling stroke at 30 days. Thirty-day mortality amounted to 13.6% (3 of 22 patients). Conclusions Simplified transapical delivery using the self-expanding SA device does not increase HITS, despite of a two-step deployment technique with more interactions with the native aortic valve, when compared to the balloon-expandable ES valve. The similarity in HITS count, frequency and pattern with the two systems suggests a common mechanism for the release of cerebral microemboli.

Finite element analysis in asymptomatic, symptomatic, and ruptured abdominal aortic aneurysms: in search of new rupture risk predictors.

OBJECTIVES To compare biomechanical rupture risk parameters of asymptomatic, symptomatic and ruptured abdominal aortic aneurysms (AAA) using finite element analysis (FEA). STUDY DESIGN Retrospective biomechanical single center analysis of asymptomatic, symptomatic, and ruptured AAAs. Comparison of biomechanical parameters from FEA. MATERIALS AND METHODS From 2011 to 2013 computed tomography angiography (CTA) data from 30 asymptomatic, 15 symptomatic, and 15 ruptured AAAs were collected consecutively. FEA was performed according to the successive steps of AAA vessel reconstruction, segmentation and finite element computation. Biomechanical parameters Peak Wall Rupture Risk Index (PWRI), Peak Wall Stress (PWS), and Rupture Risk Equivalent Diameter (RRED) were compared among the three subgroups. RESULTS PWRI differentiated between asymptomatic and symptomatic AAAs (p < .0004) better than PWS (p < .1453). PWRI-dependent RRED was higher in the symptomatic subgroup compared with the asymptomatic subgroup (p < .0004). Maximum AAA external diameters were comparable between the two groups (p < .1355). Ruptured AAAs showed the highest values for external diameter, total intraluminal thrombus volume, PWS, RRED, and PWRI compared with asymptomatic and symptomatic AAAs. In contrast with symptomatic and ruptured AAAs, none of the asymptomatic patients had a PWRI value >1.0. This threshold value might identify patients at imminent risk of rupture. CONCLUSIONS From different FEA derived parameters, PWRI distinguishes most precisely between asymptomatic and symptomatic AAAs. If elevated, this value may represent a negative prognostic factor for asymptomatic AAAs.

Noninvasive pressure difference mapping derived from 4D flow MRI in patients with unrepaired and repaired aortic coarctation.

PURPOSE To develop a method for computing and visualizing pressure differences derived from time-resolved velocity-encoded three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) and to compare pressure difference maps of patients with unrepaired and repaired aortic coarctation to young healthy volunteers. METHODS 4D flow MRI data of four patients with aortic coarctation either before or after repair (mean age 17 years, age range 3-28, one female, three males) and four young healthy volunteers without history of cardiovascular disease (mean age 24 years, age range 20-27, one female, three males) was acquired using a 1.5-T clinical MR scanner. Image analysis was performed with in-house developed image processing software. Relative pressures were computed based on the Navier-Stokes equation. RESULTS A standardized method for intuitive visualization of pressure difference maps was developed and successfully applied to all included patients and volunteers. Young healthy volunteers exhibited smooth and regular distribution of relative pressures in the thoracic aorta at mid systole with very similar distribution in all analyzed volunteers. Patients demonstrated disturbed pressures compared to volunteers. Changes included a pressure drop at the aortic isthmus in all patients, increased relative pressures in the aortic arch in patients with residual narrowing after repair, and increased relative pressures in the descending aorta in a patient after patch aortoplasty. CONCLUSIONS Pressure difference maps derived from 4D flow MRI can depict alterations of spatial pressure distribution in patients with repaired and unrepaired aortic coarctation. The technique might allow identifying pathophysiological conditions underlying complications after aortic coarctation repair.

3D morphometry using automated aortic segmentation in native MR angiography: an alternative to contrast enhanced MRA?

INTRODUCTION Native-MR angiography (N-MRA) is considered an imaging alternative to contrast enhanced MR angiography (CE-MRA) for patients with renal insufficiency. Lower intraluminal contrast in N-MRA often leads to failure of the segmentation process in commercial algorithms. This study introduces an in-house 3D model-based segmentation approach used to compare both sequences by automatic 3D lumen segmentation, allowing for evaluation of differences of aortic lumen diameters as well as differences in length comparing both acquisition techniques at every possible location. METHODS AND MATERIALS Sixteen healthy volunteers underwent 1.5-T-MR Angiography (MRA). For each volunteer, two different MR sequences were performed, CE-MRA: gradient echo Turbo FLASH sequence and N-MRA: respiratory-and-cardiac-gated, T2-weighted 3D SSFP. Datasets were segmented using a 3D model-based ellipse-fitting approach with a single seed point placed manually above the celiac trunk. The segmented volumes were manually cropped from left subclavian artery to celiac trunk to avoid error due to side branches. Diameters, volumes and centerline length were computed for intraindividual comparison. For statistical analysis the Wilcoxon-Signed-Ranked-Test was used. RESULTS Average centerline length obtained based on N-MRA was 239.0±23.4 mm compared to 238.6±23.5 mm for CE-MRA without significant difference (P=0.877). Average maximum diameter obtained based on N-MRA was 25.7±3.3 mm compared to 24.1±3.2 mm for CE-MRA (P<0.001). In agreement with the difference in diameters, volumes obtained based on N-MRA (100.1±35.4 cm(3)) were consistently and significantly larger compared to CE-MRA (89.2±30.0 cm(3)) (P<0.001). CONCLUSIONS 3D morphometry shows highly similar centerline lengths for N-MRA and CE-MRA, but systematically higher diameters and volumes for N-MRA.

Hemodynamic Performance of Edwards Intuity Valve in a Compliant Aortic Root Model

Numerous designs of bioprosthetic valves exist. The sutureless surgical valve is a newer design concept which combines elements of the transcatheter valve technology with surgical valves. This design aims at shorter and easier implantation. It was the aim of this study to perform hemodynamic and kinematic measurements for this type of valves to serve as a baseline for following studies which investigate the effect of the aortic root on the valve performance. To this end, the Edwards Intuity aortic valve was investigated in a new in vitro flow loop mimicking the left heart. The valve was implanted in a transparent, compliant aortic root model, and the valve kinematics was investigated using a high speed camera together with synchronized hemodynamic measurements of pressures and flows. The valve closure was asynchronous (one by one leaflet), and the valve started to close before the deceleration of the fluid. The aortic root model showed a dilation of the sinuses which was different to the ascending aorta, and the annulus was found to move towards the left ventricle during diastole and towards the aorta during systole.

Comprehensive geriatric assessment in patients undergoing transcatheter aortic valve implantation–rationale and design of the European CGA-TAVI registry

Abstract Purpose Aortic stenosis (AS) is the most common valvular abnormality in the elderly population. For inoperable patients or those at high-risk for surgery, transcatheter aortic valve implantation (TAVI) has become an alternative therapeutic option. The aim of the “Comprehensive geriatric assessment for transcatheter aortic valve implantation” (CGA-TAVI) registry is to evaluate the effectiveness of TAVI from the perspective of the geriatrician and to identify patient characteristics and indicators related to complications and clinical benefits for patients with symptomatic severe calcified degenerative AS undergoing TAVI. Materials and methods The CGA-TAVI registry is an international, multi-center, prospective, observational registry across Europe with consecutive patient enrolment. The registry will enrol up to 200 patients with AS undergoing TAVI, starting August 2013. CGA-TAVI has two co-primary objectives: (1) Establish predictive value of Comprehensive geriatric assessment (CGA) for mortality and/or hospitalization in TAVI patients. (2) Demonstrate CGA changes within 3 months after TAVI. Secondary objectives are: (1) Establish predictive value of CGA in TAVI patients for all-cause hospitalization, TAVI-related hospitalization, and nursing home admission. (2) Develop a comprehensive score for the assessment of TAVI patient prognosis. Conclusions The data obtained from the CGA-TAVI registry will supplement previous results to document the potential value of the effectiveness of TAVI from the perspective of geriatricians and will allow the assessment of the predictive value of CGA for mortality and/or hospitalization in elderly TAVI patients. Keywords Aortic stenosis; Transcatheter aortic valve implantation (TAVI); Comprehensive geriatric assessment (CGA); Registry; Predictor

High-flow venous pouch aneurysm in the rabbit carotid artery: A model for large aneurysms.

BACKGROUND AND PURPOSE Currently one of the most widely used models for the development of endovascular techniques and coiling devices for treatment of aneurysm is the elastase-induced aneurysm model in the rabbit carotid artery. Microsurgical techniques for creating an aneurysm with a venous pouch have also been established, although both techniques usually result in aneurysms less than 1 cm in diameter. We investigated whether an increase in blood flow toward the neck would produce larger aneurysms in a microsurgical venous pouch model. MATERIALS AND METHODS Microsurgical operations were performed on 11 New Zealand white rabbits. Both carotid arteries and the right jugular vein were dissected, and the right carotid artery was temporarily clipped followed by an arteriotomy. The left carotid artery was also clipped proximally, ligated distally, and sutured onto the proximal half of the arteriotomy in the right carotid artery. The venous graft was sutured onto the distal half of the arteriotomy. Digital subtraction angiography was also performed. RESULTS Angiography showed patent anastomosed vessels and aneurysms in the seven surviving rabbits. Mean aneurysm measurements among surviving rabbits with patent vessels were: 13.9 mm length, 9.3 mm width, and neck diameter 4.7 mm. The resulting mean aspect ratio was 3.35 and the mean bottleneck ratio was 3.05. CONCLUSION A large venous graft and increased blood flow toward the base of the aneurysm seem to be key factors in the creation of large venous pouch aneurysms. These large aneurysms allow testing of endovascular devices designed for large and giant aneurysms.

Effect of Pulmonary Hypertension Hemodynamic Presentation on Clinical Outcomes in Patients With Severe Symptomatic Aortic Valve Stenosis Undergoing Transcatheter Aortic Valve Implantation: Insights From the New Proposed Pulmonary Hypertension Classification.

BACKGROUND Pulmonary hypertension (PH) frequently coexists with severe aortic stenosis, and PH severity has been shown to predict outcomes after transcatheter aortic valve implantation (TAVI). The effect of PH hemodynamic presentation on clinical outcomes after TAVI is unknown. METHODS AND RESULTS Of 606 consecutive patients undergoing TAVI, 433 (71.4%) patients with severe aortic stenosis and a preprocedural right heart catheterization were assessed. Patients were dichotomized according to whether PH was present (mean pulmonary artery pressure, ≥25 mm Hg; n=325) or not (n=108). Patients with PH were further dichotomized by left ventricular end-diastolic pressure into postcapillary (left ventricular end-diastolic pressure, >15 mm Hg; n=269) and precapillary groups (left ventricular end-diastolic pressure, ≤15 mm Hg; n=56). Finally, patients with postcapillary PH were divided into isolated (n=220) and combined (n=49) subgroups according to whether the diastolic pressure difference (diastolic pulmonary artery pressure-left ventricular end-diastolic pressure) was normal (<7 mm Hg) or elevated (≥7 mm Hg). Primary end point was mortality at 1 year. PH was present in 325 of 433 (75%) patients and was predominantly postcapillary (n=269/325; 82%). Compared with baseline, systolic pulmonary artery pressure immediately improved after TAVI in patients with postcapillary combined (57.8±14.1 versus 50.4±17.3 mm Hg; P=0.015) but not in those with precapillary (49.0±12.6 versus 51.6±14.3; P=0.36). When compared with no PH, a higher 1-year mortality rate was observed in both precapillary (hazard ratio, 2.30; 95% confidence interval, 1.02-5.22; P=0.046) and combined (hazard ratio, 3.15; 95% confidence interval, 1.43-6.93; P=0.004) but not isolated PH patients (P=0.11). After adjustment, combined PH remained a strong predictor of 1-year mortality after TAVI (hazard ratio, 3.28; P=0.005). CONCLUSIONS Invasive stratification of PH according to hemodynamic presentation predicts acute response to treatment and 1-year mortality after TAVI.

Procedural Results and Clinical Outcomes of Transcatheter Aortic Valve Implantation in Switzerland: An Observational Cohort Study of Sapien 3 Versus Sapien XT Transcatheter Heart Valves.

BACKGROUND New generation transcatheter heart valves (THV) may improve clinical outcomes of transcatheter aortic valve implantation. METHODS AND RESULTS In a nationwide, prospective, multicenter cohort study (Swiss Transcatheter Aortic Valve Implantation Registry, NCT01368250), outcomes of consecutive transfemoral transcatheter aortic valve implantation patients treated with the Sapien 3 THV (S3) versus the Sapien XT THV (XT) were investigated. An overall of 153 consecutive S3 patients were compared with 445 consecutive XT patients. Postprocedural mean transprosthetic gradient (6.5±3.0 versus 7.8±6.3 mm Hg, P=0.17) did not differ between S3 and XT patients, respectively. The rate of more than mild paravalvular regurgitation (1.3% versus 5.3%, P=0.04) and of vascular (5.3% versus 16.9%, P<0.01) complications were significantly lower in S3 patients. A higher rate of new permanent pacemaker implantations was observed in patients receiving the S3 valve (17.0% versus 11.0%, P=0.01). There were no significant differences for disabling stroke (S3 1.3% versus XT 3.1%, P=0.29) and all-cause mortality (S3 3.3% versus XT 4.5%, P=0.27). CONCLUSIONS The use of the new generation S3 balloon-expandable THV reduced the risk of more than mild paravalvular regurgitation and vascular complications but was associated with an increased permanent pacemaker rate compared with the XT. Transcatheter aortic valve implantation using the newest generation balloon-expandable THV is associated with a low risk of stroke and favorable clinical outcomes. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01368250.

Validation of the Valve Academic Research Consortium Bleeding Definition in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

BACKGROUND The Valve Academic Research Consortium (VARC) has proposed a standardized definition of bleeding in patients undergoing transcatheter aortic valve interventions (TAVI). The VARC bleeding definition has not been validated or compared to other established bleeding definitions so far. Thus, we aimed to investigate the impact of bleeding and compare the predictivity of VARC bleeding events with established bleeding definitions. METHODS AND RESULTS Between August 2007 and April 2012, 489 consecutive patients with severe aortic stenosis were included into the Bern-TAVI-Registry. Every bleeding complication was adjudicated according to the definitions of VARC, BARC, TIMI, and GUSTO. Periprocedural blood loss was added to the definition of VARC, providing a modified VARC definition. A total of 152 bleeding events were observed during the index hospitalization. Bleeding severity according to VARC was associated with a gradual increase in mortality, which was comparable to the BARC, TIMI, GUSTO, and the modified VARC classifications. The predictive precision of a multivariable model for mortality at 30 days was significantly improved by adding the most serious bleeding of VARC (area under the curve [AUC], 0.773; 95% confidence interval [CI], 0.706 to 0.839), BARC (AUC, 0.776; 95% CI, 0.694 to 0.857), TIMI (AUC, 0.768; 95% CI, 0.692 to 0.844), and GUSTO (AUC, 0.791; 95% CI, 0.714 to 0.869), with the modified VARC definition resulting in the best predictivity (AUC, 0.814; 95% CI, 0.759 to 0.870). CONCLUSIONS The VARC bleeding definition offers a severity stratification that is associated with a gradual increase in mortality and prognostic information comparable to established bleeding definitions. Adding the information of periprocedural blood loss to VARC may increase the sensitivity and the predictive power of this classification.

Effect of B-type Natriuretic Peptides on Long-Term Outcomes After Transcatheter Aortic Valve Implantation.

B-type natriuretic peptide (BNP) levels are elevated in patients with aortic stenosis (AS) and decrease acutely after replacement of the stenotic valve. The long-term prognostic value of BNP after transcatheter aortic valve implantation (TAVI) and the relative prognostic utility of single versus serial peri-interventional measurements of BNP and N-terminal prohormone BNP (NT-pro-BNP) are unknown. This study sought to determine the impact of BNP levels on long-term outcomes after TAVI and to compare the utility of BNP versus NT-pro-BNP measured before and after intervention. We analyzed 340 patients with severe AS and baseline pre-TAVI assessment of BNP. In 219 patients, BNP and NT-pro-BNP were measured serially before and after intervention. Clinical outcomes over 2 years were recorded. Patients with high baseline BNP (higher tertile ≥591 pg/ml) had increased risk of all-cause mortality (adjusted hazard ratio 3.16, 95% confidence interval 1.84 to 5.42; p <0.001) and cardiovascular death at 2 years (adjusted hazard ratio 3.37, 95% confidence interval 1.78 to 6.39; p <0.001). Outcomes were most unfavorable in patients with persistently high BNP before and after intervention. Comparing the 2 biomarkers, NT-pro-BNP levels measured after TAVI showed the highest prognostic discrimination for 2-year mortality (area under the curve 0.75; p <0.01). Baseline-to-discharge reduction, but not baseline levels of BNP, was related to New York Heart Association functional improvement. In conclusion, high preintervention BNP independently predicts 2-year outcomes after TAVI, particularly when elevated levels persist after the intervention. BNP and NT-pro-BNP and their serial periprocedural changes provide complementary prognostic information for symptomatic improvement and survival.

The Impact of Pre-Operative Malperfusion on Outcome in Acute Type A Aortic Dissection: Results From the GERAADA Registry

BACKGROUND Malperfusion adversely affects outcomes in patients with acute type A aortic dissection, but reliable quantitative data are lacking. OBJECTIVES The aim of this study was to analyze the impact of various forms of malperfusion on early outcome. METHODS A total of 2,137 consecutive patients enrolled in GERAADA (German Registry for Acute Aortic Dissection Type A) who underwent surgery between 2006 and 2010, of whom 717 (33.6%) had any kind of pre-operative malperfusion, were retrospectively analyzed. RESULTS All-cause 30-day mortality was 16.9% and varied substantially according to the number of organ systems affected by malperfusion (none, 12.6%; 1 system, 21.3%; 2 systems, 30.9%; 3 systems, 43.4%; p < 0.001). Pre-operative cerebral malperfusion, comatose state, peripheral malperfusion, visceral malperfusion, involvement of supra-aortic branches, coronary malperfusion, and renal malperfusion were all independent predictors of developing any post-operative malperfusion syndrome. When survival was considered, age, peripheral malperfusion, involvement of supra-aortic branches, coronary malperfusion, spinal malperfusion, a primary entry in the descending aorta, and pre-operative comatose state were independent predictors, again with increasing significance. CONCLUSIONS Malperfusion remains a severe clinical condition with strong potential for adverse outcomes in patients undergoing surgery for acute type A aortic dissection. The GERAADA registry suggests that the impact of the number of organs involved and the type of malperfusion on outcome differs substantially. Introducing an appropriate classification system, such as "complicated" and uncomplicated" acute type A aortic dissection, might help predict individual risk as well as select a surgical strategy that may quickly resolve malperfusion.

Clinical outcomes and revascularization strategies in patients with low-flow, low-gradient severe aortic valve stenosis according to the assigned treatment modality

OBJECTIVES This study compared clinical outcomes and revascularization strategies among patients presenting with low ejection fraction, low-gradient (LEF-LG) severe aortic stenosis (AS) according to the assigned treatment modality. BACKGROUND The optimal treatment modality for patients with LEF-LG severe AS and concomitant coronary artery disease (CAD) requiring revascularization is unknown. METHODS Of 1,551 patients, 204 with LEF-LG severe AS (aortic valve area <1.0 cm(2), ejection fraction <50%, and mean gradient <40 mm Hg) were allocated to medical therapy (MT) (n = 44), surgical aortic valve replacement (SAVR) (n = 52), or transcatheter aortic valve replacement (TAVR) (n = 108). CAD complexity was assessed using the SYNTAX score (SS) in 187 of 204 patients (92%). The primary endpoint was mortality at 1 year. RESULTS LEF-LG severe AS patients undergoing SAVR were more likely to undergo complete revascularization (17 of 52, 35%) compared with TAVR (8 of 108, 8%) and MT (0 of 44, 0%) patients (p < 0.001). Compared with MT, both SAVR (adjusted hazard ratio [adj HR]: 0.16; 95% confidence interval [CI]: 0.07 to 0.38; p < 0.001) and TAVR (adj HR: 0.30; 95% CI: 0.18 to 0.52; p < 0.001) improved survival at 1 year. In TAVR and SAVR patients, CAD severity was associated with higher rates of cardiovascular death (no CAD: 12.2% vs. low SS [0 to 22], 15.3% vs. high SS [>22], 31.5%; p = 0.037) at 1 year. Compared with no CAD/complete revascularization, TAVR and SAVR patients undergoing incomplete revascularization had significantly higher 1-year cardiovascular death rates (adj HR: 2.80; 95% CI: 1.07 to 7.36; p = 0.037). CONCLUSIONS Among LEF-LG severe AS patients, SAVR and TAVR improved survival compared with MT. CAD severity was associated with worse outcomes and incomplete revascularization predicted 1-year cardiovascular mortality among TAVR and SAVR patients.

Transcarotid aortic valve-in-valve implantation for degenerated stentless aortic root conduits with severe regurgitation: a case series

OBJECTIVES Transcatheter aortic valve implantation (TAVI) is routinely performed via the transfemoral and the transapical route. Subclavian and direct aortic access are described alternatives for TAVI. Recently, the transcarotid approach has been shown to be feasible among patients with limited vascular access and severe native aortic valve stenosis. We aim to investigate the feasibility of transcatheter aortic valve-in-valve implantation via the transcarotid access in patients with severe aortic regurgitation due to degenerated stentless Shelhigh conduits using the 29 mm Medtronic CoreValve bioprosthesis. METHODS Three patients with complex vascular anatomy undergoing transcatheter valve-in-valve implantation via the transcarotid route were enrolled in the study. The procedure was performed under general anaesthesia using surgical cut-down to facilitate vascular access. Immediate procedural results as well as echocardiographic and clinical outcomes after 30 days and 6 months of the follow-up were recorded and analysed. RESULTS All three patients underwent unproblematic TAVI and experienced dramatic improvement of symptoms. Mean transvalvular gradient was 3, 6 and 11 mmHg, respectively. Effective orifice area ranged between 1.7 and 2.2 cm(2). Only mild paravalvular regurgitation was detected by echocardiography after 30 days of the follow-up. CONCLUSIONS The transcarotid approach can be safely performed for valve-in-valve procedures using the Medtronic CoreValve in patients with limited vascular access. It enables accurate positioning and implantation of the prosthesis.