United States Feasibility Study of Transcatheter Insertion of a Stented Aortic Valve by the Left Ventricular Apex

One-year outcomes of cohort 1 in the Edwards SAPIEN Aortic Bioprosthesis European Outcome (SOURCE) registry: the European registry of transcatheter aortic valve implantation using the Edwards SAPIEN valve

BACKGROUND

Transcatheter aortic valve implantation was developed to provide a therapeutic option for patients considered to be ineligible for, and to mitigate mortality and morbidity associated with, high-risk surgical aortic valve replacement.

METHODS AND RESULTS

The Edwards SAPIEN Aortic Bioprosthesis European Outcome (SOURCE) Registry was designed to assess initial post commercial clinical transcatheter aortic valve implantation results of the Edwards SAPIEN valve in consecutive patients in Europe. Cohort 1 consists of 1038 patients enrolled at 32 centers. One-year outcomes are presented. Patients with the transapical approach (n=575) suffered more comorbidities than transfemoral patients (n=463) with a significantly higher logistic EuroSCORE (29% versus 25.8%; P=0.007). These groups are different; therefore, outcomes cannot be directly compared. Total Kaplan Meier 1-year survival was 76.1% overall, 72.1% for transapical and 81.1% for transfemoral patients, and 73.5% of surviving patients were in New York Heart Association (NYHA) class I or II at 1 year. Combined transapical and transfemoral causes of death were cardiac in 25.1%, noncardiac in 49.2%, and unknown in 25.7%. Pulmonary complications (23.9%), renal failure (12.5%), cancer (11.4%), and stroke (10.2%) were the most frequent noncardiac causes of death. Multivariable analysis identified logistic EuroSCORE, renal disease, liver disease, and smoking as variables with the highest hazard ratios for 1-year mortality whereas carotid artery stenosis, hyperlipidemia, and hypertension were associated with lower mortality.

CONCLUSION

The SOURCE Registry is the largest consecutively enrolled registry for transcatheter aortic valve implantation procedures. It demonstrates that with new transcatheter aortic techniques excellent 1-year survival in high-risk and inoperable patients is achievable and provides a benchmark against which future transcatheter aortic valve implantation cohorts and devices can be measured.

Transapical aortic valve implantation at 3 years

OBJECTIVE

Our objective was to analyze the results of transapical aortic valve implantation in high-risk patients with aortic stenosis at up to 3 years after the procedure.

METHODS

A total of 299 patients underwent transapical aortic valve implantation from February 2006 until January 2010 using the Edwards SAPIEN transcatheter xenograft. Mean patient age was 82 ± 6 years and 70% were female. Logistic EuroSCORE and Society of Thoracic Surgeons score predicted risks for mortality were 31% ± 16% and 12% ± 8%, respectively. All patients were treated in a hybrid operative theater by a team of anesthetists, cardiologists and cardiac surgeons.

RESULTS

Successful valve implantation was performed in all patients. Transapical aortic valve implantation was uneventful in 267 patients (89.3%), whereas 32 patients (10.7%) required additional interventions. Such interventions included cardiopulmonary bypass support in 18, implantation of a second SAPIEN valve in 15, coronary intervention in 9, conversion to conventional surgery in 6, and annulus perforation in 3 patients (not mutually exclusive). Intraprocedural stroke was not observed in any patient, although 2 (0.7%) patients had a delayed stroke during their hospital stay. Overall survival was 91% at 30 days, 73% at 1 year, 68% at 2 years, and 58% at 3 years.

CONCLUSIONS

Transapical aortic valve implantation can be performed with good outcomes in high-risk patients with aortic stenosis. Perioperative complications occur in approximately 10% of patients, and a variety of interventions are required for these events. We believe a team approach is therefore essential for the success of transapical aortic valve implantation.

[Transcutaneous aortic valve implantation: Anesthetic and perioperative management]

OBJECTIVE

To describe the perioperative management, from the point of view of the anesthesia-intensive care unit specialist, of patients with aortic stenosis who undergo transcatheter aortic valve implantation (femoral or apical TAVI).

DATA SOURCE

The PubMed database (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) was queried, using the following keywords: aortic stenosis, transcatheter aortic valve implantation TAVI, outcome, complications, anesthesia.

DATA SYNTHESIS

TAVI is performed in patients suffering from aortic stenosis and presenting with numerous comorbidities, high-predicted perioperative mortality and/or contraindications to conventional cardiac surgery. TAVI is performed either by percutaneous transfemoral or transapical puncture of the left ventricle (LV) apex. These patients are older, have more comorbidities than those undergoing aortic valve replacement surgery and perioperative mortality predicted by risk scores is higher. While transapical TAVI is performed with general anaesthesia, transfemoral TAVI can be performed with either general or locoregional anaesthesia and/or sedation. The choice of the anaesthetic technique for transfemoral TAVI depends on the patient's medical history, the technique chosen for valve implantation, the type of monitoring and the anticipated hemodynamic problems. The incidence of complications following TAVI is high, some are common to surgical aortic valve replacement, and others are specific to this technique. Because of the prevalence of comorbidities, the hemodynamic-specific constraints of this technique and the incidence of complications, anaesthetic and perioperative management (evaluation, anaesthetic technique, monitoring, post-surgery care) requires the same level of expertise as in cardiac surgery anaesthesia.

CONCLUSION

TAVI expands treatment options for patients with aortic valve stenosis. The anaesthesia team must be involved in the care of these patients with the same level of expertise and care as in heart surgery on critical patients.

Usefulness of TEE as the primary imaging technique to guide transcatheter transapical aortic valve implantation

OBJECTIVES

The aim of this study was to: 1) determine the usefulness of transesophageal echocardiography (TEE) as the primary technique to guide transapical (TA) transcatheter aortic valve implantation (TAVI); and 2) to compare TEE with angiography as the primary imaging modality for TA-TAVI guidance.

BACKGROUND

TEE has been routinely used as an adjunct to angiography during TA-TAVI procedures, but very few data exist on the use of TEE as the primary imaging technique guiding TA-TAVI.

METHODS

One hundred consecutive high-risk patients (mean age 79 ± 9 years, mean logistic EuroSCORE: 25.8 ± 17.6%) who underwent TA-TAVI in our center were included. The Edwards valve was used in all cases, and all procedures were performed in an operating room without hybrid facilities. The TA-TAVI was primarily guided by angiography in the first 25 patients (A-TAVI group) and by TEE in the last 75 patients (TEE-TAVI group). Procedural, 30-day, and follow-up results were evaluated.

RESULTS

No differences were observed between groups at baseline except for a higher (p = 0.001) prevalence of moderate or severe mitral regurgitation in the TEE-TAVI group. The procedure was successful in 97.3% and 100% of the patients in the TEE-TAVI and A-TAVI groups, respectively (p = 1.0), and a lower contrast volume was used in the TEE-TAVI group (12 [5 to 20] ml vs. 40 [20 to 50] ml, p < 0.0001). There were no differences between groups in the occurrence of valve malposition needing a second valve (TEE-TAVI: 5.3%; A-TAVI: 4%; p = 1.0) or valve embolization (TEE-TAVI: 1.3%; A-TAVI: 4%; p = 0.44). The results regarding post-procedural valve hemodynamic status and aortic regurgitation were similar between groups. The survival rates at 30-day and 1-year follow-up were 87% and 75% in the TEE-group and 88% and 84% in the A-TAVI group, respectively (log-rank = 0.49).

CONCLUSIONS

TEE-TAVI was associated with similar acute and midterm results as A-TAVI and significantly reduced contrast media use during the procedures. These results suggest the feasibility and safety of performing TA-TAVI procedures in an operating room without hybrid facilities, but larger studies are needed to confirm these findings.

Transcatheter versus surgical aortic-valve replacement in high-risk patients

BACKGROUND

The use of transcatheter aortic-valve replacement has been shown to reduce mortality among high-risk patients with aortic stenosis who are not candidates for surgical replacement. However, the two procedures have not been compared in a randomized trial involving high-risk patients who are still candidates for surgical replacement.

METHODS

At 25 centers, we randomly assigned 699 high-risk patients with severe aortic stenosis to undergo either transcatheter aortic-valve replacement with a balloon-expandable bovine pericardial valve (either a transfemoral or a transapical approach) or surgical replacement. The primary end point was death from any cause at 1 year. The primary hypothesis was that transcatheter replacement is not inferior to surgical replacement.

RESULTS

The rates of death from any cause were 3.4% in the transcatheter group and 6.5% in the surgical group at 30 days (P=0.07) and 24.2% and 26.8%, respectively, at 1 year (P=0.44), a reduction of 2.6 percentage points in the transcatheter group (upper limit of the 95% confidence interval, 3.0 percentage points; predefined margin, 7.5 percentage points; P=0.001 for noninferiority). The rates of major stroke were 3.8% in the transcatheter group and 2.1% in the surgical group at 30 days (P=0.20) and 5.1% and 2.4%, respectively, at 1 year (P=0.07). At 30 days, major vascular complications were significantly more frequent with transcatheter replacement (11.0% vs. 3.2%, P<0.001); adverse events that were more frequent after surgical replacement included major bleeding (9.3% vs. 19.5%, P<0.001) and new-onset atrial fibrillation (8.6% vs. 16.0%, P=0.006). More patients undergoing transcatheter replacement had an improvement in symptoms at 30 days, but by 1 year, there was not a significant between-group difference.

CONCLUSIONS

In high-risk patients with severe aortic stenosis, transcatheter and surgical procedures for aortic-valve replacement were associated with similar rates of survival at 1 year, although there were important differences in periprocedural risks. (Funded by Edwards Lifesciences; Clinical Trials.gov number, NCT00530894.).

[Transapical aortic valve implantation--indications, risks and limitations]

Calcified aortic stenosis is the predominant valve disease in the western world. Currently, surgical aortic valve replacement is the gold standard procedure for symptomatic severe aortic stenosis that can be performed with low morbidity and mortality. The prevalence of aortic stenosis increases with age, and the incidence of several comorbidities also unavoidably elevates the risk of surgical treatment. Therefore, the most adequate and gentle treatment is needed especially for this population. Since the first transcatheter aortic valve implantation (TAVI) was performed in 2002, the main implanting routes are the transfemoral, retrograde access through the common femoral artery, and the antegrade, transapical approach via anterolateral minithoracotomy. Meanwhile, TAVI has become an alternative treatment for patients who are not suitable candidates for surgical therapy in some centers.The initial clinical results are promising and have confirmed the feasibility of this technique. Due to the restricted long-term data, conventional aortic valve replacement still remains the standard for the treatment of aortic stenosis. Selection of the suitable therapy approach (surgical replacement, transfemoral or transapical aortic valve implantation) must consider each patient's specific risk profile and individual indication. Prospective, randomized trials will be necessary to assess the individual survival benefit of TAVI for various risk populations and to extend the indication.

Incidence and treatment of procedural cardiovascular complications associated with trans-arterial and trans-apical interventional aortic valve implantation in 412 consecutive patients

OBJECTIVE

Trans-catheter aortic valve implantation (TAVI) technology is rapidly evolving, with 412 procedures having been performed at our institution. Herein, we report a complete, prospective analysis of complications occurring during transvascular and trans-apical implantations with two different prostheses.

METHODS

Between June 2007 and June 2010, 412 patients (258 female, mean age 80.3±7.2 years, logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) 20.2%±13.0%) underwent TAVI through either a retrograde (n=252 transfemoral, n=28 transaxillary, and n=5 transaortic) or antegrade (n=127 trans-apical) approach at our institution. The trans-apical access was chosen only in cases where transvascular implantation was not possible. As many as 283 CoreValve and 129 Edwards Sapien prostheses were implanted.

RESULTS

Thirty-day survival was 90.9%. Vascular complications occurred in 42 patients (10.2%). In four patients, lethal aortic root (n=3) or abdominal (n=1) aortic rupture occurred. Pericardial effusion developed in 53 patients (12.8%), which resulted in cardiac tamponade in 12 patients (2.9%). Twenty-three patients (5.6%) with valve malplacement were treated interventionally. In five patients (1.2%), emergency institution of cardiopulmonary bypass was required during the procedure for temporary support; all patients survived. Seventeen patients underwent re-intervention on the catheter valve (4.1%).

CONCLUSIONS

With growing experience, complications with TAVI may be avoided by proper patient selection and skillful management. Other complications, when they occur, require a specific treatment algorithm to avoid delay in decision making. A considerable number of complications after TAVI require surgical treatment. Therefore, the ideal environment for TAVI procedures is a hybrid operating room, where a multidisciplinary team of surgeons, cardiologists, and anesthesiologists is best fitted to meet the current needs associated with TAVI technology. A reduction in complications was seen after 300 cases. This finding attests to the complexity of the procedure in addition to the experience required to reduce the incidence of complications.

Early and late (one year) outcomes following transcatheter aortic valve implantation in patients with severe aortic stenosis (from the United States REVIVAL trial)

Transcatheter aortic valve implantation (TAVI) with the Cribier-Edwards prosthesis may provide an alternative to conventional aortic valve replacement in high-risk patients with aortic stenosis. Previous studies have indicated that TAVI is feasible in this patient population. Transcatheter implantation of a Cribier-Edwards prosthesis was attempted in 55 patients in a United States Food and Drug Administration-approved prospective observational study. Clinical and echocardiographic outcomes were assessed in hospital and at 30 days, 6 months, and 12 months. Fifty-five patients (55% women, mean age 83 years) with a mean aortic valve area of 0.57 ± 0.14 cm(2) and a mean logistic European System for Cardiac Operative Risk Evaluation score of 33.5 ± 17.0% were enrolled. Transcatheter heart valves were implanted successfully in 48 patients (87%). Mean echocardiographic aortic valve area improved from 0.56 ± 0.14 to 1.6 ± 0.48 cm(2) after the procedure (p <0.0001). Thirty-day all-cause mortality and major adverse cardiac and cerebrovascular events were 7.3% and 20%, respectively. There were also 7 major procedural vascular complications (12.7%). Mortality and major adverse cardiac and cerebrovascular events increased to 23.6% and 32.7%, respectively, at 1 year, with most late events related to underlying co-morbidities. Mean New York Heart Association functional class improved from 3.22 ± 0.66 at baseline to 1.50 ± 0.85 at 1 year follow-up (p <0.001). In conclusion, TAVI in high-risk patients with aortic stenosis was feasible, with sustained clinical benefit at 12 months. Procedural complications and late major adverse cardiac and cerebrovascular events, however, overshadowed the overall clinical benefit of TAVI in this high-risk patient population.

Transcatheter valve-in-valve implantation for failing bioprosthetic valves

Transcatheter valve implantation is becoming an alternative to conventional surgical valve replacement in patients at high surgical risk. While experience and acceptance with transcatheter techniques increased rapidly, transcatheter valve implantation within failing bioprostheses has emerged as a new concept (valve-in-valve implantation). Currently, the majority of prostheses implanted in patients are bioprosthetic valves that are expected to degenerate over time. Valve-in-valve implantation provides great utility in high-operative-risk patients since the mortality risk for reoperation can be significantly higher than for first-time isolated valve replacement. Although two current devices are CE Mark approved in Europe for implantation within native valves, off-label clinical implementation of valve-in-valve have been described in numerous case reports. In this article, we provide an overview of transcatheter valve implantation in failing bioprostheses with an emphasis on the aortic position.

Combined Transapical Aortic Valve Replacement and Minimally Invasive Direct Coronary Bypass Grafting�A New Concept for Selected High-Risk Patients

Background: Transcatheter aortic valve implantation and minimally invasive direct coronary artery bypass (MIDCAB) procedures are both off-pump treatment options for a subset of higher-risk patients. We present a new, minimally invasive surgical concept involving combining the procedures and performing them through the same thoracic access in a patient with a vascular disorder.Case Report: We report on a 78-year-old patient with symptomatic calcified aortic stenosis and a critical lesion of the left anterior descending coronary artery. In addition, Rendu-Osler-Weber disease was diagnosed. He was successfully treated with combined off-pump transapical, transcatheter aortic valve implantation and MIDCAB grafting. The initial postoperative recovery was good; however, the patient died 3 months postoperatively from septic complications.Conclusion: This combined procedure performed through the same anterolateral incision was technically feasible and may be a promising, minimally invasive approach for selected patients.

Standardized endpoint definitions for transcatheter aortic valve implantation clinical trials: a consensus report from the Valve Academic Research Consortium

OBJECTIVES

To propose standardized consensus definitions for important clinical endpoints in transcatheter aortic valve implantation (TAVI), investigations in an effort to improve the quality of clinical research and to enable meaningful comparisons between clinical trials. To make these consensus definitions accessible to all stakeholders in TAVI clinical research through a peer reviewed publication, on behalf of the public health.

BACKGROUND

Transcatheter aortic valve implantation may provide a worthwhile less invasive treatment in many patients with severe aortic stenosis and since its introduction to the medical community in 2002, there has been an explosive growth in procedures. The integration of TAVI into daily clinical practice should be guided by academic activities, which requires a harmonized and structured process for data collection, interpretation, and reporting during well-conducted clinical trials.

METHODS AND RESULTS

The Valve Academic Research Consortium established an independent collaboration between Academic Research organizations and specialty societies (cardiology and cardiac surgery) in the USA and Europe. Two meetings, in San Francisco, California (September 2009) and in Amsterdam, the Netherlands (December 2009), including key physician experts, and representatives from the US Food and Drug Administration (FDA) and device manufacturers, were focused on creating consistent endpoint definitions and consensus recommendations for implementation in TAVI clinical research programs. Important considerations in developing endpoint definitions included (i) respect for the historical legacy of surgical valve guidelines; (ii) identification of pathophysiological mechanisms associated with clinical events; (iii) emphasis on clinical relevance. Consensus criteria were developed for the following endpoints: mortality, myocardial infarction, stroke, bleeding, acute kidney injury, vascular complications, and prosthetic valve performance. Composite endpoints for TAVI safety and effectiveness were also recommended.

CONCLUSION

Although consensus criteria will invariably include certain arbitrary features, an organized multidisciplinary process to develop specific definitions for TAVI clinical research should provide consistency across studies that can facilitate the evaluation of this new important catheter-based therapy. The broadly based consensus endpoint definitions described in this document may be useful for regulatory and clinical trial purposes.

Percutaneous transarterial aortic valve implantation: what do we know?

Transcatheter aortic valve implantation (TAVI) is assuming a major role in the routine management of patients with aortic stenosis. Surgical aortic valve replacement is generally accepted to prolong survival, on the basis of historical comparisons and long experience. However, recently percutaneous transarterial TAVI has assumed the position as the only therapy in any aortic stenosis patient group demonstrated to prolong survival in a randomized trial. Arguably, percutaneous TAVI is now the standard of care in symptomatic patients who are not candidates for conventional surgery. On the basis of almost 10 years of experience TAVI also appears to be a reasonable option for some operable, but high-risk patients. Nevertheless considerable work needs to be done before the indications for TAVI are expanded into lower risk groups. We review what is currently known about percutaneous transarterial implantation of the aortic valve.

Incidence and Management of CoreValve Dislocation During Transcatheter Aortic Valve Implantation

Background—

Transcatheter aortic valve implantation is a highly specialized technique offering a new therapeutic option to patients at high risk for conventional surgery. Complications associated with this catheter procedure differ from complications after surgical aortic valve replacement. This is to report incidence, management, and impact on morbidity and mortality of CoreValve dislocation during catheter valve implantation.

Methods and Results—

Between June 2007 and September 2009, the self-expandable CoreValve prosthesis (Medtronic Inc, Minneapolis, Minn) was implanted in 212 patients through a transarterial (femoral or subclavian) access. Patients with severe aortic stenosis who were at high risk for conventional surgery were included. We observed dislocation of the prosthesis during CoreValve implantation in 21 patients. In 16 cases, the CoreValve could be implanted in the correct annular position after retrieving it and reloading the catheter. In 4 patients, the completely deployed prosthesis had to be placed in the ascending or abdominal aorta before implanting a second one. One patient underwent open surgery. Overall 30-day mortality was 11.0%, 21.5% in the dislocation group and 9.9% in patients without dislocation ( P =0.024). Coronary ischemia, stroke, and renal failure occurred more frequently in patients with dislocation, whereas pacemaker dependency did not differ significantly between the groups.

Conclusions—

CoreValve dislocation during transcatheter aortic valve implantation occurred in 10% of the cases and significantly increases perioperative risk for severe complications or death. It requires individual specific management and can be managed either interventionally or, rarely, results in open surgery.

Transapical aortic valve replacement under real-time magnetic resonance imaging guidance: experimental results with balloon-expandable and self-expanding stents

OBJECTIVE

Aortic valves have been implanted on self-expanding (SE) and balloon-expandable (BE) stents minimally invasively. We have demonstrated the advantages of transapical aortic valve implantation (tAVI) under real-time magnetic resonance imaging (rtMRI) guidance. Whether there are different advantages to SE or BE stents is unknown. We report rtMRI-guided tAVI in a porcine model using both SE and BE stents, and compare the differences between the stents.

METHODS

A total of 22 Yucatan pigs (45-57 kg) underwent tAVI. Commercially available stentless bioprostheses (21-25 mm) were mounted on either BE platinum-iridium stents or SE-nitinol stents. rtMRI guidance was employed as the intraoperative imaging. Markers on both types of stents were used to enhance visualization in rtMRI. Pigs were allowed to survive and had follow-up MRI scans and echocardiography at 1, 3, and 6 months postoperatively.

RESULTS

rtMRI provided excellent visualization of the aortic valve implantation mounted on both stent types. The implantation times were shorter with the SE stents (60 ± 14s) than with the BE stents (74 ± 18s), (p=0.027). The total procedure time was 31 and 37 min, respectively (p=0.12). It was considerably easier to manipulate the SE stent during deployment, without hemodynamic compromise. This was not always the case with the BE stent, and its placement occasionally resulted in coronary obstruction and death. Long-term results demonstrated stability of the implants with preservation of myocardial perfusion and function over time for both stents.

CONCLUSIONS

SE stents were easier to position and deploy, thus leading to fewer complications during tAVI. Future optimization of SE stent design should improve clinical results.

Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery

BACKGROUND

Many patients with severe aortic stenosis and coexisting conditions are not candidates for surgical replacement of the aortic valve. Recently, transcatheter aortic-valve implantation (TAVI) has been suggested as a less invasive treatment for high-risk patients with aortic stenosis.

METHODS

We randomly assigned patients with severe aortic stenosis, whom surgeons considered not to be suitable candidates for surgery, to standard therapy (including balloon aortic valvuloplasty) or transfemoral transcatheter implantation of a balloon-expandable bovine pericardial valve. The primary end point was the rate of death from any cause.

RESULTS

A total of 358 patients with aortic stenosis who were not considered to be suitable candidates for surgery underwent randomization at 21 centers (17 in the United States). At 1 year, the rate of death from any cause (Kaplan–Meier analysis) was 30.7% with TAVI, as compared with 50.7% with standard therapy (hazard ratio with TAVI, 0.55; 95% confidence interval [CI], 0.40 to 0.74; P<0.001). The rate of the composite end point of death from any cause or repeat hospitalization was 42.5% with TAVI as compared with 71.6% with standard therapy (hazard ratio, 0.46; 95% CI, 0.35 to 0.59; P<0.001). Among survivors at 1 year, the rate of cardiac symptoms (New York Heart Association class III or IV) was lower among patients who had undergone TAVI than among those who had received standard therapy (25.2% vs. 58.0%, P<0.001). At 30 days, TAVI, as compared with standard therapy, was associated with a higher incidence of major strokes (5.0% vs. 1.1%, P=0.06) and major vascular complications (16.2% vs. 1.1%, P<0.001). In the year after TAVI, there was no deterioration in the functioning of the bioprosthetic valve, as assessed by evidence of stenosis or regurgitation on an echocardiogram.

CONCLUSIONS

In patients with severe aortic stenosis who were not suitable candidates for surgery, TAVI, as compared with standard therapy, significantly reduced the rates of death from any cause, the composite end point of death from any cause or repeat hospitalization, and cardiac symptoms, despite the higher incidence of major strokes and major vascular events. (Funded by Edwards Lifesciences; ClinicalTrials.gov number, NCT00530894.).

The next revolution: percutaneous aortic valve replacement

Aortic valve replacement (AVR) is a treatment of choice for patients with symptomatic severe aortic stenosis (AS). However, a significant proportion of these patients do not undergo surgical AVR due to high-risk features. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative for patients with severe AS who are not candidates for open-heart surgery. Since the introduction of TAVI to the medical community in 2002, there has been an explosive growth in procedures. The balloon-expandable Edwards SAPIEN valve and the self-expanding CoreValve ReValving(TM) system contribute the largest patient experience with more than 10,000 patients treated with TAVI to date. Clinical outcomes have stabilized in experienced hands, with 30-day mortality less than 10%. Careful patient selection, growing operator experience, and an integrated multidisciplinary team approach contribute to notable improvement in outcomes. In the first randomized pivotal PARTNER trial, in patients with severe AS not suitable candidates for surgical AVR, TAVI compared with standard therapy, significantly improved survival and cardiac symptoms, but was associated with higher incidence of major strokes and major vascular events. The results of randomized comparison of TAVI with AVR among high-risk patients with AS for whom surgery is a viable option are eagerly awaited to provide further evidence on the applicability of TAVI in these patients.

Left ventricular reverse remodeling in percutaneous and surgical aortic bioprostheses: an echocardiographic study

BACKGROUND

Surgical aortic valve replacement (SAVR) is the definitive proven therapy for patients with severe aortic stenosis who have symptoms or decreased left ventricular (LV) function. The development of transcatheter aortic valve implantation (TAVI) offers a viable and "less invasive" option for the treatment of patients with critical aortic stenosis at high risk with conventional approaches. The main objective of this study was the comparison of LV hemodynamic and structural modifications (reverse remodeling) between percutaneous and surgical approaches in the treatment of severe aortic stenosis.

METHODS

Fifty-eight patients who underwent TAVI with the CoreValve bioprosthetic valve were compared with 58 patients with similar characteristics who underwent SAVR. Doppler echocardiographic data were obtained before the intervention, at discharge, and after 6-month to 12-month follow-up.

RESULTS

Mean transprosthetic gradient at discharge was lower (P<.003) in the TAVI group (10±5 mm Hg) compared with the SAVR group (14±5 mm Hg) and was confirmed at follow-up (10±4 vs 13±4 mm Hg, respectively, P<.001). Paravalvular leaks were more frequent in the TAVI group (trivial to mild, 69%; moderate, 14%) than in the SAVR group (trivial to mild, 30%; moderate, 0%) (P<.0001). The incidence of severe prosthesis-patient mismatch (PPM) was significantly lower (P<.004) in the TAVI group (12%) compared with the SAVR group (36%). At follow-up, LV mass and LV mass indexed to height and to body surface area improved in both groups, with no significant difference. In patients with severe PPM, only the TAVI subgroup showed significant reductions in LV mass. LV ejection fraction improved at follow-up significantly only in TAVI patients compared with baseline values (from 50.2±9.6% to 54.8±7.3%, P<.0001).

CONCLUSIONS

Hemodynamic performance after TAVI was shown to be superior to that after SAVR in terms of transprosthetic gradient, LV ejection fraction, and the prevention of severe PPM, but with a higher incidence of aortic regurgitation. Furthermore, LV reverse remodeling was observed in all patients in the absence of PPM, while the same remodeling occurred only in the TAVI subgroup when severe PPM was present.

Safety and efficacy of the subclavian approach for transcatheter aortic valve implantation with the CoreValve revalving system

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is a new option for patients with severe aortic stenosis at high surgical risk. The standard retrograde approach through the femoral artery is contraindicated in case of unfavorable iliofemoral anatomy or extensive disease. In these patients, a trans-subclavian approach may be feasible.

METHODS AND RESULTS

Between June 2007 and July 2009, TAVI with the CoreValve bioprosthesis (Medtronic, Minneapolis, Minn) was performed in 514 consecutive patients at 13 Italian hospitals, using the subclavian approach in 54 cases. The median logistic EuroSCORE was significantly higher in the subclavian (19.4; interquartile range, 12.5 to 29.8) versus femoral group (25.3; interquartile range, 15.1 to 36.6) (P=0.03), as well as the rate of comorbidities. Procedural success was obtained in 100% versus 98.4% of the subclavian versus femoral groups, respectively (P=0.62), with intraprocedural mortality of 0% versus 0.9% (P=1.00). The most common in-hospital complications were a new left bundle-branch block (22.4%) and the need for pacemaker (16.3%). No specific complications for the subclavian access (vessel rupture, vertebral or internal mammary ischemia) were reported. The learning curve for the subclavian approach led to a wider use of local anesthesia. Thirty-day mortality was 0% versus 6.1% in the subclavian versus femoral groups, respectively (P=0.13). Six-month mortality rate was 9.4% versus 15.8% (P=0.44), whereas valve-related adverse events were 13.6% versus 13.9% (P=0.79).

CONCLUSIONS

TAVI through the subclavian approach appeared feasible and safe, with excellent procedural success and low in-hospital complication rates. This new technique allows patients with contraindications to the femoral approach to be treated with TAVI.

Thirty-day results of the SAPIEN aortic Bioprosthesis European Outcome (SOURCE) Registry: A European registry of transcatheter aortic valve implantation using the Edwards SAPIEN valve

BACKGROUND

Transcatheter aortic valve implantation was developed to mitigate the mortality and morbidity associated with high-risk traditional aortic valve replacement. The Edwards SAPIEN valve was approved for transcatheter aortic valve implantation transfemoral delivery in the European Union in November 2007 and for transapical delivery in January 2008.

METHODS AND RESULTS

The SAPIEN Aortic Bioprosthesis European Outcome (SOURCE) Registry was designed to assess the initial clinical results of the Edwards SAPIEN valve in consecutive patients in Europe after commercialization. Cohort 1 consists of 1038 patients enrolled at 32 centers. Patients who were treated with the transapical approach (n=575) suffered more comorbidities than the transfemoral patients (n=463), resulting in a significantly higher logistic EuroSCORE (29.1% versus 25.7%; P<0.001). Therefore, these groups are considered different, and outcomes cannot be compared. Overall short-term procedural success was observed in 93.8%. The incidence of valve embolization was 0.3% (n=3), and coronary obstruction was reported for 0.6% (n=6 cases). Incidence of stroke was 2.5% and similar for both procedural approaches. Thirty-day mortality was 6.3% in transfemoral patients and 10.3% in transapical patients. The occurrence of vascular complications was not a predictor of <30-day mortality in the transfemoral population.

CONCLUSIONS

Technical proficiency can be learned and adapted readily as demonstrated by the short-term procedural success rate and low 30-day mortality rates reported in the SOURCE Registry. Specific complication management and refinement of patient selection are needed to further improve outcomes.

Transcatheter aortic valve implantation for high risk patients with severe aortic stenosis using the Edwards Sapien balloon-expandable bioprosthesis: a single centre study with immediate and medium-term outcomes

BACKGROUND

Transcatheter aortic valve implantation (TCAVI) is an emerging alternative therapy to open-heart surgery in high-risk patients with symptomatic aortic stenosis.

METHODS

Between January 2007 and May 2009, 46 patients underwent TCAVI with the 23 mm or 26 mm Edwards Sapien bioprosthesis via either the transapical (TA-AVI) or transfemoral (TF-AVI) approach. All patients had an estimated operative mortality risk of >15%.

RESULTS

A total of 46 patients (30 TA-AVI, 16 TF-AVI) with a mean aortic valve area (AVA) of 0.63 +/- 0.2 cm(2) and mean gradient of 54 +/- 16 mm Hg were treated. Predicted operative mortality was 25.3% by logistic Euroscore and 8.7% by Society of Thoracic Surgeons risk score. Procedural success was 93% in the TA-AVI group and 88% in the TF-AVI group. There was one intraprocedural death in the TA-AVI group. Overall 30-day mortality was 6.5% (2-TA-AVI, 1-TF-AVI). Four patients (9.5%) died from noncardiac causes after 30 days. Successful TCAVI was associated with a significant increase in AVA from 0.6 +/- 0.1 cm(2) to 1.6 +/- 0.6 cm(2) in the TA-AVI group and 0.6 +/- 0.1 cm(2) to 1.4 +/- 0.2 cm(2) in the TF-AVI group at a mean follow up of 7.4 +/- 4.4 and 8.3 +/- 5.0 months, respectively. At discharge, there was significant improvement in AVA (P < 0.0001), transaortic mean gradient (P < 0.0001), and mitral regurgitation (P = 0.01). At medium term follow up, the valve area was maintained and there was significant improvement in NYHA class in both groups (P < 0.0001).

CONCLUSION

At medium term follow-up, both transcatheter approaches demonstrated good valve durability with no cardiac-related mortality post hospital discharge.

The future of new aortic valve replacement approaches

Aortic valve disease is a growing cause of mortality and morbidity, especially in developed countries. Whereas medical therapy is associated with an ominous prognosis, since the 1970s, surgical valve replacement has represented a standard therapy for fit patients. Indeed, this approach is safe and feasible in younger patients without comorbidities. However, in unfit patients, surgery may be associated with a very high risk. The advent of transcatheter valve replacement techniques, by means of percutaneous or transapical approaches, has been recently introduced into mainstream clinical practice and is likely to radically change the treatment of aortic valve disease. At present, further data are needed to thoroughly appraise the long-term risk–benefit balance of transcatheter valve replacement techniques. For this reason, it can only be considered for high surgical risk patients, but early results are so promising that in the future, transcatheter aortic valve implantation could became the first therapeutic choice, even for low-risk patients.

Transcatheter aortic valves inadequately relieve stenosis in small degenerated bioprostheses

OBJECTIVES

Transcatheter aortic valves (TAVs) are a promising treatment for high risk surgical patients suffering from degeneration of previously implanted bioprostheses (valve-in-valve therapy). However, unlike native stenosed aortic valves which have accommodated Edwards SAPIEN transcatheter valves after valvuloplasty, rigid bioprostheses may prevent full TAV stent expansion and disrupt leaflet function. We hypothesized that current 23 mm TAVs would not completely relieve severe stenosis in small bioprosthetic valves. The objective of this study was to study the hemodynamics of TAVs in degenerated bioprostheses.

METHODS

Twelve TAVs designed to mimic the 23 mm SAPIEN valve were created. Using a pulse duplicator, hemodynamics of valve-in-valve implantation were measured within 19, 21, and 23 mm Carpentier-Edwards PERIMOUNT degenerated bioprostheses (n=6 each). Bioprosthetic degeneration was simulated using BioGlue to achieve a mean pressure gradient of 50 mmHg.

RESULTS

TAVs significantly reduced the mean pressure gradient (50.9+/-4.7-9.1+/-4.1 mmHg, P<0.001) and total energy loss (870.3+/-157.4-307.8+/-87.3 mJ, P<0.001) in 23 mm degenerated bioprostheses. In 21 mm bioprostheses, the pressure gradient (52.3+/-7.0-19.5+/-5.0 mmHg, P<0.001) and energy loss (785.5+/-128.1-477.8+/-123.2 mJ, P=0.007) were reduced significantly. However, no significant changes in the pressure gradient (57.1+/-4.3-46.5+/-9.3 mmHg, P=0.086) or energy loss (839.3+/-49.3-960.5+/-158.1 mJ, P=0.144) were obtained after TAVI implantation in 19 mm bioprostheses. Incomplete stent expansion resulted in leaflet distortion and central regurgitation when implanted in 19 and 21 mm bioprostheses.

CONCLUSIONS

The bioprosthetic annulus and stent posts offered a suitable landing zone for TAVs. However, oversized transcatheter valves were constrained by the rigid bioprostheses resulting in inadequate resolution of bioprosthetic stenosis. Hemodynamics of valve-in-valve intervention was worse than comparable size surgical valve replacements, particularly in 19 and 21 mm valves. Small degenerated bioprostheses require modification of current TAV design to yield acceptable hemodynamics.

Transcatheter aortic valve implantation: role of multimodality cardiac imaging

Current evidence based on more than 8000 high-risk patients with severe aortic stenosis has demonstrated that transcatheter aortic valve implantation (TAVI) is a feasible alternative to surgical aortic valve replacement in selected patients. Despite current promising results on hemodynamic and clinical improvements, there are several unresolved safety issues, such as the frequency of vascular complications, postprocedural paravalvular leak, atrioventricular heart block and stroke. Multimodality cardiac imaging may help to minimize these complications and may play a central role before (optimizing patient selection, selection of appropriate prosthesis size and anticipating the procedural approach), during and after TAVI (evaluating the immediate and long-term procedural results). This article reviews the state-of-the-art TAVI procedures and the role that multimodality cardiac imaging plays before, during and after TAVI.

The utility of trans-catheter aortic valve replacement after commercialization: does the European experience provide a glimpse into the future use of this technology in the United States?

Treatment of aortic stenosis remains challenging in older individuals, as their perioperative mortality for open heart surgery is increased due to comorbidities. Transcatheter aortic valve implantation using the CoreValve ReValving System (Medtronic, Minneapolis, USA) and the Edwards SAPIEN transcatheter heart valve (THV; Edwards Lifescience, Irvine, California, USA) represents an alternative to conventional valve replacement in elderly patients that have a high risk for conventional surgery. This article summarizes the evidence-base from recent clinical trials. The early results of these landmark studies suggest that transcatheter aortic valve implantation with either one of the prosthesis is feasible, safe, improves hemodynamics and, therefore, might be an alternative to conventional aortic valve replacement in very high-risk patients. However, all of the available transcatheter heart valves have certain disadvantages, limiting their use in daily clinical practice. The process of decision making, which valve to use and which access route to choose is illustrated in this article through clinical case scenarios. Additionally, the lessons learned thus far from the European perspective and the potential impact on the future use in the US are discussed. Despite of the progress in this field, we are still lacking an optimal transcatheter heart valve. Once it is available, we can take the plunge to compare transcatheter valve implantation with convention surgery in severe aortic stenosis!

Transcatheter aortic valve replacement: a potential option for the nonsurgical patient

With improved life expectancy, the incidence of aortic stenosis is rising. However, up to one-third of patients who require lifesaving surgical aortic valve replacement are denied surgery due to a high operative mortality rate. Such patients can only be treated with medical therapy or percutaneous aortic valvuloplasty, neither of which has been shown to improve mortality. With advances in interventional cardiology, transcatheter methods have been developed for aortic valve replacement. Clinical trials are investigating these devices in patients with severe aortic stenosis that have been denied surgery. Preliminary results from these trials suggest that transcatheter aortic valve replacement (TAVR) is not only feasible, but an effective way to improve symptoms. In this review, we describe the current technology and display available outcome data. Though technical challenges and operator learning curve limit optimal use of the current technology, continued experience and advancements in technology may one day make TAVR a viable alternative to traditional surgical aortic valve replacement.