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Structural heart disease
August 2013
Transcatheter Valve News Transapical access—the multipurpose route to treating structural heart disease
CHRISTOPH HUBER
COMMENT & ANALYSIS
The transapical approach is the only antegrade route for transcatheter aortic valve implantation (TAVI) and has gained wide popularity because of its advantages over non- antegrade approaches1–3
He reviews the technical and clinical considerations of this approach A
ortic valve crossing in the antegrade transapical approach is usually performed at the first attempt and repeated attempts (as typically seen in retro- grade techniques) are avoided. The aortic arch is negotiated with minimal handling and after transcatheter exchange, a stiff guidewire is placed in the descending aorta creating a sturdy and reliable rail for the delivery system. In contrast, retrograde approaches have to make use of a pre-bend wire trapped in the left ventricle without further support and with a sustained risk of myocardial perforation. Following transapical balloon valvuloplasty under rapid pacing, the delivery system is then advanced over the wire. The delivery system is then inserted in-no touch technique without crossing of the aortic arch avoiding the risk of em- bolisation from either the ascending aorta or the aortic arch. Precise axial alignment is achieved readily and does not rely on additional technical features of the delivery system. The final step of valve implantation is eased by the shortened working distance and becomes very precise, predictable and reproducible. A lower threshold for post-implantation bal- loon re-dilatation might be another reason of significantly lesser paravalvular leaks when compared with retrograde techniques as for example the transfemoral approach. Transfemoral TAVI is generally contraindicated in pa- tients with peripheral artery disease and has been repeatedly shown to have a considerable local complication profile4,5
,
. More importantly, the rate of stroke is also re- ported to be significantly lower with the antegrade transapi- cal route when compared to retrograde delivery techniques8
affecting more than 10% of patients. In contrast, the local complication rate for the transapical access is reported to be below 1%6,7
.
The increased stroke rate of transfemoral TAVI, despite well-engineered delivery systems, might be the result of the challenging aortic arch and aortic valve crossing—possibly generating a higher amount of emboli. Additionally, the longer working distance from the femo- ral puncture site to the target area might also negatively affect the precision of placement and the delivery process. Therefore, this longer distance could be responsible for the significant increase in paravalvular regurgitation when compared with transapical results9,10
.
Despite the favourable evidence, the enthusiasm for the transapical access remains dampened because of the in- creased surgical invasiveness with the approach. However, a paradigm shift is approaching.
It has been identified that there is a growing need for a true percutaneous transapical access and as a result, many technical solutions have emerged. Access closure of the apex has become technically feasible and first experimental data have been reported. First clinical results are expected soon11
. I have been involved with the development of a self-seal-
Conflicts of interests: Christoph Huber is a proctor for Edwards Lifesciences, for Symetis and consultant for Medtronic and shareholder of Endoheart AG
References 1. Huber et al. J Endovasc Ther 2004; 11: 503–10 2. Huber et al. Transcatheter Valve Therapies 2009; 80–100 3. Huber et al. J Am Coll Cardiol 2005; 46: 366–70 4. Wenaweser et al. Am Heart J 2011; 161: 1114–24 5. Stortecky et al. JACC Cardiovasc Interv 2012; 5: 515–24 6. Unbehaun et al. J Am Coll Cardiol 2012; 59:211–21 7. Thomas et al. Circulation 2011; 124:425–33 8. Eggebrecht et al. EuroInterventio 2012; 8: 129–38 9. Gilard et al. FRANCE 2 Investigators. N Engl J Med 2012; 366: 1705–15 10. Van Belle E. J Am Coll Cardiol 2012; 60 (TCT 91) 11. Blumenstein et al. Ann Thorac Surg 2012; 94: 1706–09
“TAVI with CoreValve represents good value for healthcare spending”
M
edtronic has revealed the results of a cost-effectiveness model comparing transcatheter aortic
valve implantation (TAVI) with the Cor- eValve system to medical management. Presented at EuroPCR (21–24 May, Paris, France), the UK-based analysis compared the “real-world” Medtronic CoreValve ADVANCE study to the medical manage- ment cohort of the PARTNER B study and found that the CoreValve System was cost-effective. Patients participating in this study had severe aortic stenosis and were unable to undergo surgery. According to a Medtronic press release, for both treatment pathways the cost-ef- fectiveness model compared the benefits (including life years gained and improve- ment in quality of life) to lifetime costs
(including procedure, device, physician, hospitalisations and other measures) from the perspective of the NHS in the UK. Well below many developed countries’ cost-effectiveness thresholds, the cost of TAVI with the CoreValve System to gain a year of life was £7,700, and the cost per quality of life year gained was near £11,300. “With the low mortality and stroke rates, and the overall improvement in quality of life found in the ADVANCE study, TAVI with CoreValve has shown its worth in medical terms. What this study does is benchmark the financial costs: We can now compare the cost-effectiveness of this intervention against other accepted therapies delivered in a national health- care delivery system. What we find is that
despite the high costs of TAVI, it stacks up extremely favourably in terms of QALYs. In short, it is cost effective,” concluded Stephen Brecker, St George’s Hospital in London, UK, who presented the cost- effectiveness data at EuroPCR. “It is gratifying to know that in addition to excellent outcomes, in the current economic climate TAVI with CoreValve represents good value for healthcare spending.” The CoreValve ADVANCE study was conducted across 44 centres in 12 coun- tries. In ADVANCE, clinical endpoints are calculated according to Valve Academic Research Consortium (VARC) standard- ised definitions. All data were indepen- dently monitored, all adverse events related to primary endpoints were adju-
dicated by an independent clinical events committee (CEC), and all cerebrovascular events (including stroke and other events) were adjudicated by an independent neu- rologist using neuroimaging and system- atic NIH Stroke Scale assessments. According to the company, since receiving the CE mark in 2007, the CoreValve System has been implanted in more than 40,000 patients in more than 60 countries. The CoreValve system is available in four valve sizes (23mm, 26mm, 29mm and 31mm), each deliver- able via transfemoral, subclavian and direct aortic access through a low-profile, 18Fr delivery catheter. It is not currently approved for commercial use in the USA and is currently undergoing clinical trials in that territory.
. Christoph Huber is the inventor of the transapical TAVI technique.
ing device—the TA Plug (Endoheart). It is the first device to have successfully sealed large calibre transapical access up to 39F sheath diameter in a true-percutaneous fashion in animal experiments. Other closure devices rely on au- tomated suture mediated closure or myocardial anchoring. These technical developments clearly indicate the growing need of a facilitated transapical access. Reliable and safe true-percutaneous entry and closure of the transapical access site have become as essential as automated access closure for transfemoral transcatheter techniques for successful methodical adoption. Transapical access to the aortic valve and to other intra-cardiac structures is the most direct and most promising route for transcatheter treatment of structural heart disease or even coronary heart disease. The access choice for TAVI seems unfortunately often dictated by a strategy of the least invasiveness and a referring bias and not by clinical evidence or the patient’s best inter- ests. The true-percutaneous transapical TAVI assembles all patients’ benefits including device durability and eased procedural handling resulting in improved overall outcomes. Transapical access harbours the potential to become first choice TAVI access in the near future.
Christoph Huber, consultant cardiac surgeon and director of the Surgical TAVI Program, Swiss Cardiovascular Cen- tre, Department of Cardiovascular Surgery, University Hos- pital of Bern, Switzerland. He is the editor of the textbook Transcatheter Valve Therapies (Informa healthcare USA);
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