Philipp Kahlert

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.

Risk of stroke after transcatheter aortic valve implantation (TAVI): a meta-analysis of 10,037 published patients.

AIMS Transcatheter aortic valve implantation (TAVI) represents a novel treatment option for inoperable or high surgical risk patients with severe symptomatic aortic valve disease. Recent randomised studies have raised major safety concerns because of increased stroke/transient ischemic attack (TIA) rates with TAVI compared to medical treatment and conventional aortic valve replacement. We aimed to review all currently published literature and estimate the incidence of periprocedural stroke and outcomes in patients undergoing TAVI. METHODS AND RESULTS Fifty-three studies including a total of 10,037 patients undergoing transfemoral, transapical or trans-subclavian TAVI for native aortic valve stenosis published between 01/2004 and 11/2011 were identified and included in a meta-analysis. Patients were 81.5 ± 1.8-years-old and had a mean logistic EuroSCORE of 24.77 ± 5.60%. Procedural stroke (<24 h) occurred in 1.5 ± 1.4%. The overall 30-day stroke/TIA was 3.3 ± 1.8%, with the majority being major strokes (2.9 ± 1.8%). During the first year after TAVI, stroke/TIA increased up to 5.2 ± 3.4%. Differences in stroke rates were associated with different approaches and valve prostheses used with lowest stroke rates after transapical TAVI (2.7 ± 1.4%). Average 30-day mortality was more than 3.5-fold higher in patients with compared to those without stroke (25.5 ± 21.9% vs. 6.9 ± 4.2%). CONCLUSIONS TAVI was associated with average 30-day stroke/TIA rate of 3.3 ± 1.8% (range 0-6%). Most of these strokes were major strokes and were associated with increased mortality within in the first 30 days.

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.

Direct Assessment of Size and Shape of Noncircular Vena Contracta Area in Functional Versus Organic Mitral Regurgitation Using Real-Time Three-Dimensional Echocardiography

BACKGROUND Vena contracta width (VCW) as an estimate of effective regurgitant orifice area (EROA) is an accepted parameter of mitral regurgitation (MR) severity. However, uncertainty exists in cases in which VCW at the same time appears narrow in 4-chamber (4CH) view and broad in 2-chamber (2CH) view as common in functional MR with noncircular or slit-like regurgitant orifices. We therefore hypothesized that new real-time 3-dimensional color Doppler echocardiography (RT3DE) can be used for direct assessment of the size and shape of vena contracta area (VCA) in an en face view and to determine the potential error of conventional VCW measurement on estimation of EROA. METHODS RT3DE was performed in 57 patients with relevant MR of different etiologies. Manual tracing of VCA in a cross-sectional plane through the vena contracta was compared with VCW in 4CH and 2CH views. As a comparative approach to VCA-3D, EROA was calculated using the hemispheric and hemielliptic proximal isovelocity surface (PISA) area method. RESULTS Direct measurement of VCA-3D was feasible in all patients within 2.6 +/- 0.7 minutes. RT3DE revealed significant asymmetry of VCA in functional compared with organic MR (P < .001). Among all patients, VCW-4CH and VCW-2CH correlated only moderately to VCA-3D (r =.77; r =.80). Mean VCW correlated and agreed best with VCA-3D (r =.90). VCA-3D correlated and agreed well with EROA by hemielliptic PISA (r = .96, mean error: -0.09 +/- 0.14 cm(2)) compared with significant underestimation of hemispheric PISA in noncircular lesions. CONCLUSIONS Direct assessment of VCA using RT3DE revealed significant asymmetry of VCA in functional MR compared with organic MR, resulting in poor estimation of EROA by single VCW measurements.

Valve-in-Valve Transcatheter Aortic Valve Implantation for Degenerated Bioprosthetic Heart Valves

OBJECTIVES We sought to analyze outcomes of patients with degenerated surgically implanted bioprosthetic heart valves undergoing valve-in-valve (viv) transcatheter aortic valve implantation (TAVI). BACKGROUND Redo cardiac surgery for degenerated bioprosthetic heart valves is associated with increased risks, particular in elderly patients with comorbidities. For these patients, TAVI may be an attractive, less invasive treatment option. METHODS Data from 47 patients age 64 to 97 years (logistic euroSCORE: 35.0 ± 18.5%) undergoing transfemoral (n = 25) or transapical (n = 22) viv-TAVI for failed bioprosthetic aortic valves 113 ± 65 months after initial surgery at 9 clinical sites in Germany and Switzerland were analyzed. RESULTS Valve-in-valve TAVI was technically successful in all patients, with 2 patients requiring bailout implantation of a second TAVI prosthesis for severe regurgitation during the procedure. There was 1 procedural death as the result of low-output failure. Valvular function after viv-TAVI was excellent with respect to valve competence, but increased transvalvular gradients ≥20 mm Hg were noted in 44% of patients. Vascular access complications occurred in 6 (13%) patients, and 5 (11%) patients required new pacemaker implantation after viv-TAVI. Renal failure requiring dialysis occurred in 4 (9%) patients. Mortality at 30 days was 17% (1 procedural and 7 post-procedural deaths), with 3 of 8 fatalities the result of non-valve-related septic complications. CONCLUSIONS Valve-in-valve TAVI can be performed with high technical success rates, acceptable post-procedural valvular function, and excellent functional improvement. However, in these predominantly elderly high-risk patients with multiple comorbidities, viv-TAVI was associated with 17% mortality, often because of septic complications arising in the post-operative phase.

Intramural hematoma and penetrating ulcers: indications to endovascular treatment.

Intramural hematoma (IMH) of the aorta and penetrating aortic ulcer (PAU) are important variant forms of classic double-barrel aortic dissection in patients presenting with acute aortic syndrome. Recent insights provided by modern high-resolution imaging are currently challenging previous pathophysiologic concepts underlying IMH and PAU, suggesting a close relationship of both entities. Thoracic endovascular aortic repair (TEVAR) offers a less invasive approach to the treatment of affected patients with very encouraging early to midterm results. This review discusses current indication for TEVAR in IMH and PAU patients in the view of an improved understanding of these diseases.

Percutaneous Transvenous Mitral Annuloplasty: Initial Human Experience With a Novel Coronary Sinus Implant Device

Background—We assessed the safety and feasibility of permanent implantation of a novel coronary sinus mitral repair device (PTMA, Viacor Inc). Methods and Results—Symptomatic (New York Heart Association class 2 or 3) patients with primarily functional mitral regurgitation (MR) were included. A diagnostic PTMA procedure was performed in the coronary sinus venous continuity. MR was assessed and the PTMA device adjusted to optimize efficacy. If MR reduction (≥1 grade) was observed, placement of a PTMA implant was attempted. Implanted patients were evaluated with echocardiographic, quality of life, and exercise capacity metrics. Nineteen patients received a diagnostic PTMA study. Diagnostic PTMA was effective in 13 patients (MR grade 3.2±0.6 reduced to 2.0±1.0), and PTMA implants were placed in 9 patients. Four devices were removed uneventfully (7, 84, 197, and 216 days), 3 for annuloplasty surgery due to observed PTMA device migration and/or diminished efficacy. No procedure or device-related major adverse events with permanent sequela were observed in any of the diagnostic or implant patients. Sustained reductions of mitral annulus septal-lateral dimension from 3D echo reconstruction dimensions were observed (4.0±1.2 mm at 3 months). Conclusions—Percutaneous implantation of the PTMA device is feasible and safe. Acute results demonstrate a possibly meaningful reduction of MR in responding patients. Sustained favorable geometric modification of the mitral annulus has been observed, though reduction of MR has been limited. The PTMA method warrants continued evaluation and development.

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.

Revival of an old method with new techniques: balloon aortic valvuloplasty of the calcified aortic stenosis in the elderly.

Balloon aortic valvuloplasty (BAV), introduced since almost 20 years, has experienced a revival for its use in the treatment of elderly patients with severe calcified aortic stenosis that are associated with high operative risk and co-morbidities. This is due to the introduction of new balloon catheters and techniques. This study reports about 75 such cases performed within the past 28 months. The mean age of our patient group was 78 ± 7 years (median = 80 years). Risk calculation with the EuroSCORE demonstrated an average value of 24.4 ± 19.5%. BAV was performed along with burst pacing to reduce transvalvular blood flow for stabilization of the balloon catheter until blood pressure dropped to less than 50 mmHg. BAV was performed in 72 patients with a procedural success rate of 73%. There was a decrease of 31 mmHg peak-to-peak gradient across the aortic valve from 63 ± 35 to 32 ± 22 mmHg (P < 0.0001). Mean gradient was reduced from 51 ± 24 to 27 ± 15 mmHg (P < 0.0001). Aortic valve area increased by 49% from 0.84 ± 0.33 to 1.25 ± 0.45 cm2 (P < 0.0001). Serious adverse events (SAE) occurred in 17% of the 75 BAV procedures. Follow-up revealed a significant improvement in 6-month and 1-year survival. The improved technology of BAV makes this technique attractive for elderly patients who are at high operative risk or in cases where valve replacement was refused for any reason.

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.