Daniel Wendt

Silent and Apparent Cerebral Ischemia After Percutaneous Transfemoral Aortic Valve Implantation A Diffusion-Weighted Magnetic Resonance Imaging Study

Background— The risk of stroke after transfemoral aortic valve implantation (TAVI) due to dislodgement and subsequent embolization of debris from aortic arch atheroma or from the calcified valve itself ranges between 2% and 10%. The rate of clinically silent cerebral ischemia is unknown but may be even higher. Methods and Results— Thirty-two patients who underwent TAVI with the use of a balloon-expandable (n=22) or self-expandable (n=10) stent valve prosthesis were included in this descriptive study and compared with a historical control group of 21 patients undergoing open surgical aortic valve replacement. Periprocedural apparent and silent cerebral ischemia was assessed by neurological testing and serial cerebral diffusion-weighted magnetic resonance imaging at baseline, at 3.4 (2.5 to 4.4) days after the procedure, and at 3 months. TAVI was successful in all patients. After the procedure, new foci of restricted diffusion on cerebral diffusion-weighted magnetic resonance imaging were found in 27 of 32 TAVI patients (84%) and were more frequent than after open surgery (10 of 21 patients [48%]; P=0.011). These lesions were usually multiple (1 to 19 per patient) and dispersed in both hemispheres in a pattern suggesting cerebral embolization. Volumes of these lesions were significantly smaller after TAVI than after surgery (77 [59 to 94] versus 224 [111 to 338] mm3; P<0.001). There were neither measurable impairments of neurocognitive function nor apparent neurological events during the in-hospital period among TAVI patients, but there was 1 stroke (5%) in the surgical patient group. On 3-month follow-up diffusion-weighted magnetic resonance imaging, there were no new foci of restricted diffusion, and there was no residual signal change associated with the majority (80%) of the foci detected in the periprocedural period. Conclusions— Clinically silent new foci of restricted diffusion on cerebral magnetic resonance imaging were detected in almost all patients (84%) undergoing TAVI. Although typically multiple, these foci were not associated with apparent neurological events or measurable deterioration of neurocognitive function during 3-month follow-up. Further work needs to be directed to determine the clinical significance of these findings in a larger patient population.

Cardioprotective and prognostic effects of remote ischaemic preconditioning in patients undergoing coronary artery bypass surgery: a single-centre randomised, double-blind, controlled trial

BACKGROUND Remote ischaemic preconditioning has been associated with reduced risk of myocardial injury after coronary artery bypass graft (CABG) surgery. We investigated the safety and efficacy of this procedure. METHODS Eligible patients were those scheduled to undergo elective isolated first-time CABG surgery under cold crystalloid cardioplegia and cardiopulmonary bypass at the West-German Heart Centre, Essen, Germany, between April, 2008, and October, 2012. Patients were prospectively randomised to receive remote ischaemic preconditioning (three cycles of 5 min ischaemia and 5 min reperfusion in the left upper arm after induction of anaesthesia) or no ischaemic preconditioning (control). The primary endpoint was myocardial injury, as reflected by the geometric mean area under the curve (AUC) for perioperative concentrations of cardiac troponin I (cTnI) in serum in the first 72 h after CABG. Mortality was the main safety endpoint. Analysis was done in intention-to-treat and per-protocol populations. This trial is registered with ClinicalTrials.gov, number NCT01406678. FINDINGS 329 patients were enrolled. Baseline characteristics and perioperative data did not differ between groups. cTnI AUC was 266 ng/mL over 72 h (95% CI 237-298) in the remote ischaemic preconditioning group and 321 ng/mL (287-360) in the control group. In the intention-to-treat population, the ratio of remote ischaemic preconditioning to control for cTnI AUC was 0·83 (95% CI 0·70-0·97, p=0·022). cTnI release remained lower in the per-protocol analysis (0·79, 0·66-0·94, p=0·001). All-cause mortality was assessed over 1·54 (SD 1·22) years and was lower with remote ischaemic preconditioning than without (ratio 0·27, 95% CI 0·08-0·98, p=0·046). INTERPRETATION Remote ischaemic preconditioning provided perioperative myocardial protection and improved the prognosis of patients undergoing elective CABG surgery. FUNDING German Research Foundation.

Cerebral Embolization During Transcatheter Aortic Valve Implantation A Transcranial Doppler Study

Background— Transcatheter aortic valve implantation (TAVI) is associated with a higher risk of neurological events for both the transfemoral and transapical approach than surgical valve replacement. Cerebral magnetic resonance imaging has revealed more new, albeit clinically silent lesions from procedural embolization, yet the main source and predominant procedural step of emboli remain unclear. Methods and Results— Eighty-three patients underwent transfemoral (Medtronic CoreValve [MCVTF], n=32; Edwards Sapien [ESTF], n=26) and transapical (ESTA: n=25) TAVI. Serial transcranial Doppler examinations before, during, and 3 months after TAVI were used to identify high-intensity transient signals (HITS) as a surrogate for microembolization. Procedural HITS were detected in all patients, predominantly during manipulation of the calcified aortic valve while stent valves were being positioned and implanted. The balloon-expandable ES prosthesis caused significantly more HITS (mean [95% CI]) during positioning (ESTF, 259.9 [184.8–334.9]; ESTA, 206.1[162.5–249.7]; MCVTF, 78.5 [25.3–131.6]; P<0.001) and the self-expandable MCV prosthesis during implantation (MCVTF, 397.1 [302.1–492.2]; ESTF, 88.2 [70.2–106.3]; ESTA, 110.7 [82.0–139.3]; P<0.001). Overall, there were no significant differences between transfemoral and transapical TAVI or between the MCV and ES prostheses. No HITS were detected at baseline or 3-month follow-up. There was 1 major procedural stroke that resulted in death and 1 minor procedural stroke with full recovery at 3-month follow-up in the MCV group. Conclusions— Procedural HITS were detected by transcranial Doppler in all patients. Although no difference was observed between the transfemoral and the transapical approach with the balloon-expandable ES stent valve, transfemoral TAVI with the self-expandable MCV prosthesis resulted in the greatest number of HITS, predominantly during implantation.

Vascular Access Site Complications after Percutaneous Transfemoral Aortic Valve Implantation

Background and Purpose:Transcatheter aortic valve implantation (TAVI) is a rapidly emerging treatment option for patients with aortic valve stenosis and high surgical risk. Different access routes have been proposed for TAVI including transapical, transsubclavian and transfemoral, with percutaneous transfemoral being the preferred because least invasive and nonsurgical. However, vascular access site complications due to the large-bore delivery catheters remain an important clinical issue, particularly with respect to the elderly patient collective typically considered for TAVI. In the study, the authors analyzed their 4-year TAVI experience with respect to vascular complications and their management in patients undergoing completely percutaneous transfemoral TAVI procedures.Patients and Methods:Since 2006, TAVI was performed in 101 consecutive patients at the West German Heart Center Essen. 33 patients underwent transapical TAVI, eight patients transfemoral TAVI with surgical access or closure, and 60 patients percutaneous transfemoral TAVI using two commercially available prosthetic valve devices.Results:Completely percutaneous TAVI was technically successful in all but one patient with malpositioning in the aortic arch during valve retrieval. There was no intraprocedural death and 30-day mortality was 12% (7/60). Vascular access site complications occurred in 19 patients (32%), necessitating surgical repair in six of them (10%). Complications included retroperitoneal hematoma (n = 2), iliac or femoral artery dissection (n = 10), (pseudo)aneurysm formation (n = 3), and closure device-induced vessel stenosis/ occlusion (n = 6). Of these, 13 cases could be managed either conservatively (n = 5) or by contralateral endovascular treatment (n = 8).Conclusion:Completely percutaneous TAVI has a high acute success rate with low intraprocedural and 30-day mortality. The patient collective appears to be prone to vascular complications which remain an important limitation of this novel technique. Although conservative or endovascular management is possible in the majority of cases, further technological developments are obliged to reduce the vascular complication rate.ZusammenfassungHintergrund und Fragestellung:Die katheterbasierte Aortenklappenimplantation ist eine neue, in der klinischen Routine bereits breit angewandte Therapieoption für Hochrisikopatienten mit kalzifizierter Aortenklappenstenose. Während in der Anfangsphase noch eine chirurgische Freilegung der arteriellen Zugangsgefäße und damit verbunden eine Vollnarkose nötig waren, ist die Durchführung heute in einer rein perkutanen Technik und somit sogar unter Analgosedierung möglich. Aufgrund der großen Kaliber der zur Einführung und zum Vorschieben der Prothese benötigten Schleusen und Katheter birgt diese Prozedur jedoch das Risiko einer Verletzung der arteriellen Zugangsgefäße, insbesondere da diese bei den betroffenen, älteren Patienten häufig atherosklerotische Veränderungen aufweisen. Die vorliegende Untersuchung gibt einen Überblick über die vaskulären Komplikationen und mögliche Managementstrategien an einem Kollektiv von 60 konsekutiven Patienten, bei denen in rein perkutaner Technik eine transfemorale Aortenklappenimplantation durchgeführt wurde.Patienten und Methodik:Seit 2006 wurde am Westdeutschen Herzzentrum Essen bei insgesamt 101 konsekutiven Patienten eine kathetergesteuerte Aortenklappenimplantation durchgeführt, bei 33 Patienten über den transapikalen, bei 68 Patienten über den transfemoralen Zugang. Während bei den initialen acht in transfemoraler Technik behandelten Patienten noch eine chirurgische Freilegung und/oder ein chirurgischer Verschluss der Zugangsgefäße durchgeführt wurde, erfolgte die Implantation der ballonexpandierbaren Edwards-Sapien- (n = 41) und der selbstexpandierbaren CoreValve-Prothese (n = 19) bei de hemofolgenden 60 Patienten in rein perkutaner Technik unter Verwendung von Nahtverschlusssystemen.Ergebnisse:Bis auf eine Fehlpositionierung im Aortenbogen konnten alle Aortenklappenprothesen erfolgreich in rein perkutaner Technik und ohne intraprozeduralen Todesfall implantiert werden. Die 30-Tage-Mortalität betrug 12%. Postinterventionell zeigte sich eine signifikante Verbesserung der Hämodynamik mit Abfall des mittleren transaortalen Druckgradienten von 52 ± 18 auf 13 ± 6 mmHg und einer Zunahme der Klappenöffnungsfläche von 0,6 ± 0,2 auf 1,5 ± 0,3 cm2. Die Rate an vaskulären Komplikationen betrug 32% (19 von 60 Patienten). Die Komplikationen beinhalteten zwei retroperitoneale Hämatome, zehn Dissektionen der Femoral- und Iliakal gefäße, drei Aneurysmabildungen und sechs ver schluss systeminduzierte Komplikationen. In fünf Fällen erfolgte eine konservative Therapie, bei acht Patienten konnte eine katheterinterventionelle Behandlung durchgeführt werden. Eine operative Sanierung war bei sechs Patienten (10%) nötig.Schlussfolgerung:Die transfemorale Aortenklappenimplantation kann heutzutage in rein perkutaner Technik mit einer hohen Erfolgsrate, geringer Mortalität und guten hämodynamischen und klinischen Ergebnissen durchgeführt werden. Vaskuläre Komplikationen sind jedoch noch häufig und stellen eine wichtige Limitation dieser neuen Technik dar. Obwohl ein konservatives oder interventionelles Management dieser Komplikationen in der Regel möglich ist, müssen zukünftige Weiterentwicklungen in besonderem Maße auch auf eine Reduktion der vaskulären Komplikationsrate gerichtet sein.

Transcatheter aortic valve implantation in patients with very high risk for conventional aortic valve replacement.

BACKGROUND We sought to determine whether transcatheter aortic valve implantation is a reasonable treatment option in patients with a very or extremely high risk for conventional aortic valve replacement, presenting with a logistic EuroSCORE greater than 30% or a Society of Thoracic Surgeons score greater than 15%. METHODS Between May 2005 and November 2008, 39 of 85 transcatheter aortic valve implantation patients with a very high risk for aortic valve replacement underwent either transfemoral (n = 15) or transapical (n = 24) transcatheter aortic valve implantation with a mean estimated logistic EuroSCORE of 44.2% +/- 12.6% (mean +/- standard deviation) and a Society of Thoracic Surgeons score of 17.9% +/- 6.1%. Transcatheter aortic valve implantation was performed in a hybrid operative theater using the Cribier-Edwards or Edwards SAPIEN prosthesis. RESULTS Valve implantation was successful in 97% of the patients. Operative mortality was 2.6%, and mortality at 30 days was 17.9%. After valve implantation, hemodynamic improvement was assessed by decreased mean pressure gradient (p < 0.001) and increased aortic valve area (p < 0.001), accompanied by improved New York Heart Association functional status (p < 0.01). Actuarial survival was 74.4% at 3 months, 74.4% at 6 months, and 64.1% at 12 months of follow-up. Echocardiography revealed aortic regurgitation in 58% of the patients during hospital stay, 43% at 6 months of follow-up, and 40% at 12 months of follow-up, but no structural valve deterioration could be observed during the complete follow-up period. CONCLUSIONS Transcatheter aortic valve implantation in patients with severe aortic stenosis and a very high risk for aortic valve replacement is feasible and may be a reasonable treatment option in these patients.

Measurement of the aortic annulus size by real-time three-dimensional transesophageal echocardiography.

Abstract We sought to determine the level of agreement and the reproducibility of two-dimensional (2D) transthoracic (2D-TTE), 2D transesophageal (2D-TEE) and real-time three-dimensional (3D) transesophageal echocardiography (RT3D-TEE) for measurement of aortic annulus size in patients referred for transcatheter aortic valve implantation (TAVI). Accurate preoperative assessment of the dimensions of the aortic annulus is critical for patient selection and successful implantation in those undergoing TAVI for severe aortic stenosis (AS). Annulus size was measured using 2D-TTE, 2D-TEE and RT3D-TEE in 105 patients with severe AS referred for TAVI. Agreement between echocardiographic methods and interobserver variability was assessed using the Bland-Altman method and regression analysis, respectively. The mean aortic annuli were 21,7 ± 3 mm measured with 2D-TTE, 22,6 ± 2,8 mm with 2D-TEE and 22,3 ± 2,9 mm with RT3D-TEE. The results showed a small but significant mean difference and a strong correlation between the three measurement techniques (2D-TTE vs. 2D-TEE mean difference 0,84 ± 1,85 mm, r = 0,8, p < 0,0001; 2D-TEE vs. 3D-TEE 0,27 ± 1,14 mm, r = 0,91, p < 0,02; 2D-TTE vs. 3D-TEE 0,58 ± 2,21 mm, r = 0,72, p = 0,02); however, differences between measurements amounted up to 6,1 mm. Interobserver variability for 2D-TTE and 2D-TEE was substantially higher compared with RT3D-TEE. We found significant differences in the dimensions of the aortic annulus measured by 2D-TTE, 2D-TEE and RT3D-TEE. Thus, in patients referred for TAVI, the echocardiographic method used may have an impact on TAVI strategy.

Guidance of percutaneous transcatheter aortic valve implantation by real-time three-dimensional transesophageal echocardiography – A single-center experience

Percutaneous transcatheter aortic valve implantation (TAVI) is an evolving interventional therapy for high-risk, non-surgical patients with severe, symptomatic aortic valve stenosis (AS). As a standard procedure, 2D transesophageal echocardiography has been used for the preinterventional assessment of the native valve and measurement of the aortic annulus as well as for intraprocedural guidance. Recently, a new matrix array, transesophageal probe for real-time three-dimensional echocardiography (RT3D-TEE) has been introduced. We applied this new technique to monitor percutaneous aortic valve implantation and described our initial experiences with this method in patients undergoing TAVI. We hypothesized that RT3D-TEE provides improved evaluation of the native aortic valve and annulus dimension due to unlimited scan plane orientation. This new technology should also enable accurate guiding of percutaneous cardiac interventions by providing immediate information on prosthesis position and function in real-time. In our preliminiary clinical experience real-time three-dimensional transesophageal echocardiography (RT3D TEE) was demonstrated to provide improved guiding of percutaneous aortic valve replacement by superior spatial visualisation of the cardiac structures and facilitated the detection of procedure-related complications. Due to the advantages of real-time 3D TEE monitoring, this technique might improve the outcome of patients treated with percutaneous aortic valve replacement.

First clinical experience and 1-year follow-up with the sutureless 3F-Enable aortic valve prosthesis

BACKGROUND Aortic valve replacement (AVR) with extracorporeal circulation (ECC) is currently the treatment of choice for symptomatic aortic stenosis. However, patients with multiple high-risk comorbid conditions may benefit from reduced ECC time and thus, reduced myocardial ischemia, by the use of sutureless AVR. We describe the initial experience and 1-year results of our first 3F-Enable AVR implants. METHODS Between 09/05 and 12/05, six patients (age 74+/-1.8 years; three females) with symptomatic aortic stenosis (NYHA III) underwent AVR with an equine pericardial and nitinol-stented sutureless prosthesis. For additional safety up to three stay sutures were placed. Echocardiography was performed preoperatively, intraoperatively, at 6- and 12-month follow-up. Clinical data, adverse events and patient outcome were recorded prospectively. RESULTS Prosthesis sizes were 27 mm (n=3), 25 mm (n=1), 23 mm (n=1) and 21 mm (n=1). ECC time was 87+/-32 min; aortic clamp time was 56+/-24 min. Prosthesis deployment time was 148 +/- 173 s. There were no intraoperative deaths or complications. At 12-month follow-up mean pressure gradients (MPG) were 6.8+/-3.5 mmHg and aortic valve area (AVA) was 2.2 +/- 0.5 cm(2). One patient underwent successful redo AVR after 8 months due to severe paravalvular leakage (PVL), and one patient died due to lung cancer 10 months after surgery. At 12 months follow-up four out of six patients are alive and asymptotic (NYHA I) with the 3F-Enable aortic valve prosthesis, however, one patient showed mild paravalvular leakage. CONCLUSIONS These first 1-year follow-up data suggest the feasibility of this new concept of sutureless aortic valve implantation. However, severe aortic insufficiency at 8 months and paravalvular leakage at 1-year follow-up should prompt further procedural and device enhancements.

Incidence, outcome and correlates of residual paravalvular aortic regurgitation after transcatheter aortic valve implantation and importance of haemodynamic assessment.

AIMS Residual paravalvular aortic regurgitation (PAR) after transcatheter aortic valve implantation (TAVI) is common. We therefore evaluated incidence, determinants and outcome of PAR after TAVI. METHODS AND RESULTS Data from 167 consecutive transcatheter TAVI patients were analysed. PAR was graded by angiography and the pressure gradient between diastolic aortic pressure and left ventricular end-diastolic pressure (∆PDAP-LVEDP) after implantation. TAVI was technically successful in all patients. Mortality was 9% and 20% at 30 days and one year, respectively. Post-procedural PAR was absent in 54 patients (32.3%). Mild PAR was found in 89 (53.3%), moderate in 21 (12.6%), and moderate-to-severe in three patients (1.8%). Cardiovascular mortality at 30 days and one year was increased in patients with moderate and moderate-to-severe PAR compared to patients with no and mild PAR (46% vs. 4% and 73% vs. 7%, respectively, p<0.001). Receiver operating characteristic curve analysis suggested ∆PDAP-LVEDP ≤18 mmHg as a novel predictor of mortality, with an area under the curve of 0.97. CONCLUSIONS In patients undergoing TAVI, moderate and moderate-to-severe PAR was observed in 14.4% and associated with increased cardiovascular mortality. A pressure gradient ∆PDAP-LVEDP≤18 mmHg carries adverse prognosis and requires further intervention.

Cognitive function after transapical aortic valve implantation: a single-centre study with 3-month follow-up

OBJECTIVES Reports on adverse neurological events following transcatheter aortic valve implantation (TAVI) have focused on strokes, while more subtle postoperative cognitive decline has not yet been systematically investigated. In this study, we prospectively examined neurological and cognitive outcomes in patients undergoing transapical (TA) and surgical aortic valve replacement (AVR). METHODS A total of 64 patients with severe symptomatic aortic stenosis were investigated between January 2008 and July 2009. Clinical neurological examination and comprehensive neuropsychological testing were performed before and after the procedure, at discharge and at 3-month follow-up. Diffusion-weighted magnetic resonance imaging (DW-MRI) was applied to detect morphological brain injury. RESULTS TA-TAVI patients (n = 27) were older and at higher surgical risk compared with surgical AVR patients (n = 37; mean age 82.2 ± 4.7 vs 67.5 ± 8.9 years; log EuroSCORE 36.4 ± 13.2 vs 2.6 ± 8.5%, both P <0.001). There was one stroke in each group (3.7 vs 2.7%, P = 0.49), both classified as embolic based on imaging characteristics. After TA-TAVI, cognitive tests showed no decline during follow-up, while, after AVR, 7 of 11 tests showed a decline early after surgery. Similarly, with-in patient analysis showed that the rate of individuals with clinically relevant cognitive decline was increased early after AVR (TA-TAVI vs AVR: 18 vs 46% at discharge [P = 0.03]; 28 vs 6% at 3 months [P = 0.04]). New focal ischaemic cerebral lesions were detected on DW-MRI in 58% (7 of 12) of patients after TA-TAVI vs 34% (12 of 35) after AVR (P = 0.13). The number of brain lesions per patient and cumulative embolic load per patient were similar between groups. An association between postoperative cerebral ischaemia and cognitive dysfunction was not found (odds ratio 2.37, 95% confidence interval 0.05-113.75, P = 0.66). CONCLUSIONS Cognitive function was only mildly impaired after TA-TAVI when compared with a marked, albeit transient, decline after surgical AVR. Focal embolic brain injury tended to occur more frequently after TA-TAVI, but this was not related to cognitive decline during the 3-month follow-up.