Transapical transcatheter aortic valve implantation in humans: initial clinical experience

Evaluation of aortic root for definition of prosthesis size by magnetic resonance imaging and cardiac computed tomography: implications for transcatheter aortic valve implantation

BACKGROUND

This study sought to compare cardiac magnetic resonance imaging (CMR) with dual source computed tomography (DSCT) for analysis of aortic root dimensions prior to transcatheter aortic valve implantation (TAVI). In addition, the potential impact of CMR and DSCT measurements on TAVI strategy defined by 2D-transesophageal echocardiography (TEE) was evaluated.

METHODS

Aortic root dimensions were measured using CMR and DSCT in 58 patients referred for evaluation of TAVI. The TAVI strategy (choice of prosthesis size and decision to implant) was based on 2D-TEE annulus measurements.

RESULTS

CMR and DSCT aortic root measurements showed an overall good correlation (r=0.86, p<0.001 for coronal aortic annulus diameters). There was also a good correlation between TEE and CMR as well as between TEE and DSCT for measurement of sagittal aortic annulus diameters (r=0.69, p<0.001). However, annulus diameters assessed by TEE (22.1±2.3mm) were significantly smaller than coronal aortic annulus diameters assessed by CMR (23.4±1.8mm, p<0.001) or DSCT (23.6±1.8, p<0.001). Regarding TAVI strategy, the agreement between TEE and sagittal CMR (kappa=0.89) as well as sagittal DSCT measurements (kappa=0.87) was statistically perfect. However, decision based on coronal CMR- or MSCT measurements would have modified TAVI strategy as compared to a TEE based choice in a significant number of patients (22% to 24%).

CONCLUSION

In patients referred for TAVI, CMR measurements of aortic root dimensions show a good correlation with DSCT measurements and thus CMR may be an alternative 3D-imaging modality. Aortic annulus measurements using TEE, CMR and DSCT were close but not identical and the method used has important potential implications on TAVI strategy.

Assessment of the aortic root using real-time 3D transesophageal echocardiography

BACKGROUND

Precise evaluation of the aortic root geometry prior to transcatheter aortic valve implantation is important for procedural success in patients with aortic stenosis (AS). To determine the potential for 3-dimensional transesophageal echocardiography (3DTEE), the aims of the present study were: (1) to assess the accuracy of 3DTEE measurements of the aortic root using multidetector computed tomography (MDCT) as a reference, and (2) to examine whether aortic root geometry differs between patients with and without AS.

METHODS AND RESULTS

  3DTEE and contrast-enhanced MDCT were performed in 35 patients. Multiplanar reconstruction was used to measure the left ventricular outflow tract (LVOT) and aortic annulus diameter/area, aortic valve area (AVA), and distances between the annulus and coronary artery ostium. The same 3DTEE measurements were performed in patients with (n=71) and without AS (n=80). Aortic annular and LVOT areas measured by 3DTEE were slightly but significantly smaller compared with values obtained with MDCT. Both methods revealed that the aortic annulus and LVOT have an oval shape. Aortic annular and LVOT area, AVA and the distances between the aortic annulus and the coronary ostia correlated well between the 2 modalities. Only minor differences in aortic root geometry were observed between patients with AS and those without.

CONCLUSIONS

The geometry of the aortic annulus can be reliably evaluated using 3DTEE as an alternative to MDCT for the assessment of aortic root.

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.

The trans-subclavian retrograde approach for transcatheter aortic valve replacement: single-center experience

OBJECTIVE

Aortic valve disease is the most common acquired valvular heart disease in adults. With the increasing elderly population, the proportion of patients with symptomatic aortic stenosis who are unsuitable for conventional surgery is increasing. Transcatheter aortic valve implantation has rapidly gained credibility as a valuable alternative to surgery to treat these patients; however, they often have severe iliac-femoral arteriopathy, which renders the transfemoral approach unusable. We report our experience with the trans-subclavian approach for transcatheter aortic valve implantation using the CoreValve (Medtronic CV Luxembourg S.a.r.l.) in 6 patients.

METHODS

In May 2008 to September 2009, 6 patients (mean age of 82 ± 5 years), with symptomatic aortic stenosis and no reasonable surgical option because of excessive risk, were excluded from percutaneous femoral CoreValve implantation because of iliac-femoral arteriopathy. These patients underwent transcatheter aortic valve implantation via the axillary artery. Procedures were performed by a combined team of cardiologists, cardiac surgeons, and anesthetists in the catheterization laboratory. The CoreValve 18F delivery system was introduced via the left subclavian artery in 6 patients, 1 with a patent left internal thoracic to left anterior descending artery graft.

RESULTS

Procedural success was obtained in all patients, and the mean aortic gradient decreased 5 mm Hg or less immediately after valve deployment. One patient required implantation of a permanent pacemaker. One patient required a subclavian covered stent implantation to treat a postimplant artery dissection associated with difficult surgical hemostasis. One patient was discharged in good condition but died of pneumonia 40 days after the procedure. All patients were asymptomatic on discharge, with good mid-term prosthesis performance.

CONCLUSIONS

Transcatheter aortic valve implantation via a surgical subclavian approach seems safe and feasible, offering a new option to treat select, inoperable, and high-risk patients with severe aortic stenosis and peripheral vasculopathy.

Minimally-invasive implantation of living tissue engineered heart valves: a comprehensive approach from autologous vascular cells to stem cells

OBJECTIVES

The aim of this study was to demonstrate the feasibility of combining the novel heart valve replacement technologies of: 1) tissue engineering; and 2) minimally-invasive implantation based on autologous cells and composite self-expandable biodegradable biomaterials.

BACKGROUND

Minimally-invasive valve replacement procedures are rapidly evolving as alternative treatment option for patients with valvular heart disease. However, currently used valve substitutes are bioprosthetic and as such have limited durability. To overcome this limitation, tissue engineering technologies provide living autologous valve replacements with regeneration and growth potential.

METHODS

Trileaflet heart valves fabricated from biodegradable synthetic scaffolds, integrated in self-expanding stents and seeded with autologous vascular or stem cells (bone marrow and peripheral blood), were generated in vitro using dynamic bioreactors. Subsequently, the tissue engineered heart valves (TEHV) were minimally-invasively implanted as pulmonary valve replacements in sheep. In vivo functionality was assessed by echocardiography and angiography up to 8 weeks. The tissue composition of explanted TEHV and corresponding control valves was analyzed.

RESULTS

The transapical implantations were successful in all animals. The TEHV demonstrated in vivo functionality with mobile but thickened leaflets. Histology revealed layered neotissues with endothelialized surfaces. Quantitative extracellular matrix analysis at 8 weeks showed higher values for deoxyribonucleic acid, collagen, and glycosaminoglycans compared to native valves. Mechanical profiles demonstrated sufficient tissue strength, but less pliability independent of the cell source.

CONCLUSIONS

This study demonstrates the principal feasibility of merging tissue engineering and minimally-invasive valve replacement technologies. Using adult stem cells is successful, enabling minimally-invasive cell harvest. Thus, this new technology may enable a valid alternative to current bioprosthetic devices.

Transcatheter aortic valve implantation: durability of clinical and hemodynamic outcomes beyond 3 years in a large patient cohort

BACKGROUND

Although short- and medium-term outcomes after transcatheter aortic valve implantation are encouraging, long-term data on valve function and clinical outcomes are limited.

METHODS AND RESULTS

Consecutive high-risk patients who had been declined as surgical candidates because of comorbidities but who underwent successful transcatheter aortic valve implantation with a balloon-expandable valve between January 2005 and December 2006 and survived past 30 days were assessed. Clinical, echocardiographic, and computed tomographic follow-up examinations were performed. Seventy patients who underwent successful procedures and survived longer than 30 days were evaluated at a minimum follow-up of 3 years. At a median follow-up of 3.7 years (interquartile range 3.4 to 4.3 years), survival was 57%. Survival at 1, 2, and 3 years was 81%, 74%, and 61%, respectively. Freedom from reoperation was 98.5% (1 patient with endocarditis). During this early procedural experience, 11 patients died within 30 days, and 8 procedures were unsuccessful. When these patients were included, overall survival was 51%. Transaortic pressure gradients increased from 10.0 mm Hg (interquartile range 8.0 to 12.0 mm Hg) immediately after the procedure to 12.1 mm Hg (interquartile range 8.6 to 16.0 mm Hg) after 3 years (P=0.03). Bioprosthetic valve area decreased from a mean of 1.7±0.4 cm(2) after the procedure to 1.4±0.3 cm(2) after 3 years (P<0.01). Aortic incompetence after implantation was trivial or mild in 84% of cases and remained unchanged or improved over time. There were no cases of structural valvular deterioration, stent fracture, deformation, or valve migration.

CONCLUSIONS

Transcatheter aortic valve implantation demonstrates good medium- to long-term durability and preserved hemodynamic function, with no evidence of structural failure. The procedure appears to offer an adequate and lasting resolution of aortic stenosis in selected patients.

Transaortic transcatheter aortic valve implantation: a novel approach for the truly "no-access option" patients

OBJECTIVES

The aim of this study was to test the safety and efficacy of the retrograde, minimally invasive, "transaortic" approach of transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve prosthesis (Medtronic, Minneapolis) as an alternative minimally invasive surgical access route.

BACKGROUND

TAVI is today recognized as an established percutaneous technique for patients with severe aortic valve stenosis (AS). However, as the number of patients screened for TAVI increases, many are found with absolutely no option for peripheral artery access.

METHODS

A new method of TAVI access, described as "transaortic" was performed in two patients A CoreValve prosthesis was implanted via the "transaortic" route. The patients were a 93- and a 84-year-old woman, both with severe PAOD. After a ministernotomy the ascending aorta was directly punctured. At the end, the access site was surgically sutured with the prepositioned sutures. The patients were at all times "off-pump" (beating heart procedure) and without IABP.

RESULTS

TAVI was successful in both cases, leading to a fall in the transvalvular gradient and there were no cases of mortality, stroke or myocardial infarction. The patients were extubated directly after the procedure, mobilized after 4 days, and were discharged home after 7 and 9 days.

CONCLUSIONS

In the rare occasion, where due to anatomical reasons transfemoral TAVI is not feasible, a minimally invasive "transaortic" approach, as described, provides an alternative option. This is especially true when the transapical route is not suitable (annulus >25 mm or contraindication to lateral thoracotomy).

Emerging approaches of transcatheter valve repair/insertion

Aortic stenosis (AS) and mitral regurgitation (MR) account for the majority of valvular diseases and their prevalence is increasing according to increased life expectancy. Surgical treatment is the gold standard, although operative risk may be high in some patients due to comorbidities and age. A large part of the patients at high surgical risk who could beneficiate of treatment are not referred to surgery. Therefore, there is a need of alternative and less invasive procedures.

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.

Transapical transcatheter aortic valve implantation: follow-up to 3 years

BACKGROUND

We performed the first human case of successful transapical transcatheter aortic valve implantation on a beating heart in October 2005, and therefore we have the longest follow-up on transapical aortic valve implantation in humans. We now report clinical and echocardiographic outcomes of transapical aortic valve implantation in 71 patients.

METHODS

Between October 2005 and February 2009, 71 patients (44 female) underwent transcatheter transapical aortic valve implantation with either 23- or 26-mm Edwards Lifesciences transcatheter bioprostheses. All patients with symptomatic aortic stenosis were declined for conventional aortic valve replacement owing to unacceptable operative risks and were not candidates for transfemoral aortic valve implantation because of poor arterial access. Clinical and echocardiographic follow-ups were performed before discharge, at 1 and 6 months, and then yearly. The mean follow-up was 12.9 +/- 11.5 months with a total of 917.3 months of follow-up.

RESULTS

Mean age was 80.0 +/- 8.1 years and predicted operative mortality was 34.5% +/- 20.4% by logistic EuroSCORE and 12.1% +/- 7.7% by The Society of Thoracic Surgeons Risk Calculator. Valves were successfully implanted in all patients. Twelve patients died within 30 days (30-day mortality: 16.9% in all patients, 33% in the first 15 patients, and 12.5% in the remainder), and 10 patients died subsequently. Overall survival at 24 and 36 months was 66.3% +/- 6.4% and 58.0% +/- 9.5%, respectively. Among 59 patients who survived at least 30 days, 24- and 36-month survivals were 79.8% +/- 6.4% and 69.8% +/- 10.9%, respectively. Late valve-related complications were rare. New York Heart Association functional class improved significantly from preoperative 3.3 +/- 0.8 to 1.8 +/- 0.8 at 24 months. The aortic valve area and mean gradient remained stable at 24 months (1.6 +/- 0.3 cm(2) and 10.3 +/- 5.9 mm Hg, respectively).

CONCLUSION

Our outcome suggests that transapical transcatheter aortic valve implantation provides sustained clinical and hemodynamic benefits for up to 36 months in selected high-risk patients with symptomatic severe aortic stenosis.

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.

Advances in percutaneous treatment for adult valvular heart disease

Valvular heart disease occurs in 2-3% of the general population with an increase in prevalence with advancing age. The aetiology of valvular heart disease has evolved in recent decades with degenerative aortic and mitral valve disease supplanting rheumatic heart disease as a primary cause. The common valve lesions to be discussed in this article are aortic stenosis and mitral regurgitation. The traditional approach to calcific aortic stenosis when either symptoms or left ventricular impairment develops is surgical aortic valve replacement and it remains a treatment with excellent outcomes. In recent years there has been interest in less invasive approaches, including percutaneous and transapical aortic valve implantation. With refinements in technology these approaches are becoming a potential treatment option, primarily for high-risk patients who may otherwise be unsuitable for traditional open surgical treatment. Catheter-based approaches for mitral valve disease are also evolving. Mitral regurgitation may often be the result of mitral annular dilatation seen in patients with an enlarged left ventricle or left atrium. Percutaneous implantation of a constricting device in the coronary sinus, which lies in close proximity to the mitral annulus, results in a change to the geometry of the mitral valve and reduced regurgitation. Another technique in patients with degenerative mitral regurgitation is the endovascular edge-to-edge repair in which coaptation of the mitral valve leaflets can be improved with a percutaneously deployed clip. Small patient series indicate that these new techniques are promising. As such, advances in percutaneous interventional and surgical approaches have the potential to further improve outcomes for selected patients with valvular heart disease.

Association of aortic valve calcification severity with the degree of aortic regurgitation after transcatheter aortic valve implantation

BACKGROUND

This study sought to examine a possible relationship between the severity of aortic valve calcification (AVC), the distribution of AVC and the degree of aortic valve regurgitation (AR) after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS).

METHODS

57 patients (22 men, 81 ± 5 years) with symptomatic AS and with a logistic EuroSCORE of 24 ± 12 were included. 38 patients (67%) received a third (18F)-generation CoreValve® aortic valve prosthesis, in 19 patients (33%) an Edwards SAPIEN™ prosthesis was implanted. Prior to TAVI dual-source computed tomography for assessment of AVC was performed. To determine the distribution of AVC the percentage of the calcium load of the most severely calcified cusp was calculated. After TAVI the degree of AR was determined by angiography and echocardiography. The severity of AR after TAVI was related to the severity and distribution of AVC.

RESULTS

There was no association between the distribution of AVC and the degree of paravalvular AR after TAVI as assessed by angiography (r = -0.02, p = 0.88). Agatston AVC scores were significantly higher in patients with AR grade ≥ 3 (5055 ± 1753, n = 3) than in patients with AR grade < 3 (1723 ± 967, p = 0.03, n = 54). Agatston AVC scores > 3000 were associated with a relevant paravalvular AR and showed a trend for increased need for second manoeuvres. There was a significant correlation between the severity of AVC and the degree of AR after AVR (r = 0.50, p < 0.001).

CONCLUSION

Patients with severe AVC have an increased risk for a relevant AR after TAVI as well as a trend for increased need for additional procedures.

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.

Midterm results of transapical aortic valve replacement via real-time magnetic resonance imaging guidance

OBJECTIVE

Percutaneous valve replacements are presently being evaluated in clinical trials. As delivery of the valve is catheter based, the safety and efficacy of these procedures may be influenced by the imaging used. To assist the surgeon and improve the success of the operation, we have performed transapical aortic valve replacements using real-time magnetic resonance imaging guidance.

METHODS

Twenty-eight swine underwent aortic valve replacement by real-time magnetic resonance imaging on the beating heart. Stentless bioprostheses mounted on balloon-expandable stents were used. Magnetic resonance imaging (1.5 T) was used to identify the critical anatomic landmarks. In addition to anatomic confirmation of adequate placement of the prosthesis, functional assessment of the valve and left ventricle and perfusion were also obtained with magnetic resonance imaging. A series of short-term feasibility experiments were conducted (n = 18) in which the animals were humanely killed after valve placement and assessment by magnetic resonance imaging. Ten additional animals were allowed to survive and had follow-up magnetic resonance imaging scans and confirmatory echocardiography at 1, 3, and 6 months postoperatively.

RESULTS

Real-time magnetic resonance imaging provided superior visualization of the landmarks needed. The time to implantation after apical access was 74 +/- 18 seconds. Perfusion scanning demonstrated adequate coronary flow and functional imaging documented preservation of ventricular contractility in all animals after successful deployment. Phase contrast imaging revealed minimal intravalvular or paravalvular leaks. Longer term results demonstrated stability of the implants with preservation of myocardial perfusion and function over time.

CONCLUSIONS

Real-time magnetic resonance imaging provides excellent visualization for intraoperative guidance of aortic valve replacement on the beating heart. Additionally, it allows assessment of tissue perfusion and organ function that is not obtainable by conventional imaging alone.

Technical considerations to avoid pitfalls during transapical aortic valve implantation

OBJECTIVE

Transapical aortic valve implantation is a recent therapeutic advance for aortic valvular disease. We sought to identify complications--and the relevant technical and management considerations--from our learning curve with this procedure.

METHODS

We retrospectively reviewed perioperative complications during the first 60 transapical aortic valve implantations at a single institution, performed under compassionate release for patients who were candidates neither for conventional aortic valve replacement nor for transfemoral aortic valve implantation. Access was through a small left anterolateral thoracotomy. Particular attention was paid to securing the apical access site. Rapid ventricular pacing to reduce cardiac forward flow was used during balloon valvuloplasty and valve deployment. Careful positioning was guided by echocardiography and fluoroscopy.

RESULTS

This was a select, high-risk (mean Society of Thoracic Surgeons score, 12.3% +/- 7.8% mortality) cohort. Mean age was 81.1 +/- 7.8 years. Technical success was achieved in 59 (98.3%) cases. One valve was malpositioned too far toward the ventricle, necessitating that a second device be implanted within it. In-hospital, 30-day mortality was 18.3% (11 deaths) overall, decreasing from 33.3% in the first 15 patients to 13.3% in the subsequent 45 patients. The only intraoperative death probably resulted from left main ostial obstruction by extensively calcified aortic cusps. Significant left ventricular apical bleeding occurred in 3 (5.0%) patients. Other complications included stroke in 2 (3.3%) patients and permanent atrioventricular block in 3 (5.0%). There were 4 (6.6%) cases of late pseudoaneurysm of the left ventricular apical access site.

CONCLUSIONS

Important lessons have been learned from our early experience with transapical aortic valve implantation, and these may guide others as this technology is adopted more broadly.

Multimodal assessment of the aortic annulus diameter: implications for transcatheter aortic valve implantation

OBJECTIVES

We sought to compare 3 methods of measurements of the aortic annulus, transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and multislice computed tomography (MSCT), and to evaluate their potential clinical impact on transcatheter aortic valve implantation (TAVI) strategy.

BACKGROUND

Exact measurement of the aortic annulus is critical for a patient's selection and successful implantation.

METHODS

Annulus diameter was measured using TTE, TEE, and MSCT in 45 consecutive patients with severe aortic stenosis referred for TAVI. The TAVI strategy (decision to implant and choice of the prosthesis' size) was based on manufacturer's recommendations (Edwards-Sapien prosthesis, Edwards Lifesciences, Inc., Irvine, California).

RESULTS

Correlations between methods were good but the difference between MSCT and TTE (1.22 +/- 1.3 mm) or TEE (1.52 +/- 1.1 mm) was larger than the difference between TTE and TEE (0.6 +/- 0.8 mm; p = 0.03 and p < 0.0001, respectively). Regarding TAVI strategy, agreement between TTE and TEE overall was good (kappa = 0.68), but TAVI strategy would have been different in 8 patients (17%). Agreement between MSCT and TTE or TEE was only modest (kappa = 0.28 and 0.27), and a decision based on MSCT measurements would have modified the TAVI strategy in a large number of patients (40% to 42%). Implantation, performed in 34 patients (76%) based on TEE measurements, was successful in all but 1 patient with grade 3/4 regurgitation.

CONCLUSIONS

In patients referred for TAVI, measurements of the aortic annulus using TTE, TEE, and MSCT were close but not identical, and the method used has important potential clinical implications on TAVI strategy. In the absence of a gold standard, a strategy based on TEE measurements provided good clinical results.