The bioresorbable vascular scaffold, Absorb, is changing the landscape of percutaneous coronary interventions by offering the advantages of XIENCE coupled with its own differentiated benefits
The content is provided by Abbott Vascular International
Cardiovascular diseases (CVD) remain the main cause of mortality in most European countries, causing 1.9 million deaths yearly despite the constant decrease seen over the last 30 years.(1) The importance of CVD led the European Society of Cardiology to organise an event in Brussels from 4–8 November 2013. The European Parliament hosted the first Cardiovascular Health Week to raise awareness around the theme ‘Mind Your Heart – for a Heart Healthy Europe’ towards politicians and aimed at putting CVD as a top health priority in European countries.
Within CVD, coronary artery diseases (CAD) affect a large population and generate an important economic burden to society due to high healthcare expenditure and lost productivity. In the US and Europe, total spending (direct and indirect costs, including lost productivity) on CAD is estimated to be in excess of $177 billion(2) and €60 billion,(3) respectively.
With the societal health and economic burden of CAD set to increase in conjunction with both an ageing global population(4) and increasing prevalence of CAD risk factors in developing regions,(5) there is a requirement for the continued development of highly efficacious, minimally-invasive, and cost-effective techniques with which to manage this disease.
The Economic Intelligence Unit, White Paper January 2014, Succeeding in a Value-Based Environment,(6) states that: ‘Innovative and gold standard treatments should address the challenges of our value based environment supporting the provision of good or better health while being accessible to the largest possible population.’
Currently, there are two types of drug-eluting stents (DES) available: DES that are coated with a permanent durable polymer (durable polymer-coated DES; DP-DES) and those coated with a biodegradable polymer (called biodegradable polymer DES; BP-DES). Both types leave a permanent implant in the body. Fully bioresorbable implants, (called bioresorbable vascular scaffolds; BVS), like Abbott’s Absorb, have recently been introduced (Figure 1). These implants disappear fully through a natural metabolic process, and are designed to overcome limitations associated with permanent metallic implants.
XIENCE – excellent efficacy and safety profile
XIENCE is the most studied DP-DES, with over 62,000 patients enrolled in clinical trials,(7) and is recognised as the DES gold standard.(8) Several network meta-analyses (NMA)(9–11) have been published recently, investigating and comparing a composite of BMS, DP-DES, and BP-DES.
In summary, as pointed out in an editorial published in the British Medical Journal, these studies suggest that everolimus‑eluting stents, such as XIENCE, are probably the safest of the contemporary DES; DES with biodegradable polymer do not seem to have lived up to their initial promise. They are not more effective than the best DP-DES (everolimus-eluting stent), and certainly not safer, as in some comparisons they were linked to increased myocardial infarctions and deaths.(12)
Impact of stent safety on readmission rate and quality of care
Hospital readmissions are seen as an indicator of hospital quality and have attracted the attention of policymakers as a way to improve quality of care while simultaneously reducing costs. Reducing the number of readmissions is considered to be a pillar of cost-effective hospital care.(13)
Several countries such as the UK, Germany and the Netherlands have introduced measures within their reimbursement systems whereby hospitals are paid for the initial treatment but not paid again if the patient is brought back for treatment within a short period of time (30 days for the UK and Germany, and 42 days for The Netherlands).(14) Therefore, choosing a best-in-class stent for percutaneous coronary interventions will help to avoid unwanted and costly re-admissions due to adverse events such as stent thrombosis.
Coronary stent thrombosis (ST) is the sudden occlusion of a stented coronary artery due to a formation of thrombus within the stent or stented area. Mortality due to stent thrombosis has been reported to be as high as 45%.(15) Non-fatal stent thrombosis not only impacts patients’ lives but also has implications for both the hospital budget and the overall
Different stents have different safety/stent thrombosis profiles.(9–11) How do these differences translate in daily practice for a cath lab treating 1000 patients/year? Figure 2 hypothesises the estimated numbers of definite ST events that occur at 30 days across various DES.(16–18)
XIENCE shows the lowest number of stent thrombosis events both at early and late stage. The differences shown at 30 days(16–18) have a financial impact for the hospital as in quite some Western European countries, there is no reimbursement for any re-interventions taking place within 30 days of the index procedure.
This early advantage is confirmed in the long-term as in a cathlab of 1000 patients, XIENCE can avoid up to 22 stent thrombosis events at two years(19) reducing the need for resource utilisation related to re-intervention and avoiding a negative impact on a patient’s life.
Next to direct medical costs, stent thrombosis has an impact on additional aspects including the quality of life of patients and families, productivity losses for active and working patients, the image of the treating hospital.
In today’s world, where cost-effectiveness and quality of care are more and more important, one needs to certainly consider the safety profiles of the different DES.
Absorb: the fourth revolution in PCI
Bioresorbable vascular scaffolds, which are considered the fourth revolution in PCI, should couple comparable or improved long-term clinical outcomes of the gold standard DES with complete resorption over time, thereby adding specific benefits that are not feasible with metallic implants. Absorb is the first commercially available drug-eluting BVS and obtained a CE mark on 14 December, 2010.
To date, Absorb has shown similar benefits of a best-in-class DES. In ABSORB clinical trials, Absorb performance is comparable with XIENCE.(20,21)
Absorb is designed to offer improved patient satisfaction,(22) indicated by a strong patient preference for bioresorbable scaffolds over permanent metallic stents.
The use of Absorb continues to be evaluated through a robust global clinical trial programme. These trials include both randomised and non-randomised studies designed to continue to evaluate both the safety and efficacy of Absorb as well as health economic endpoints. To date over 4000(23) patients have been treated with Absorb in clinical studies, and an additional 17,000(24) patients are expected to be enrolled in the next two years, reflecting the significant investment and support Abbott Vascular has made towards this revolutionary therapy.
The absence of a permanent metallic cage means Absorb may offer benefits to different patient populations:
- Restoration of more natural vessel function may allow patients to enjoy many years of life with vessels that can respond to physiological demands in the absence of a permanent metallic cage – this could maximise lifetime patient health
- Absorb may broaden future treatment choices for patients requiring
- re-treatment, ensuring optimal patient therapy
- Full resorption of the device, may lead to lower angina rates, which is beneficial for the patient’s quality of life. A propensity matched analysis comparing site-reported angina events through one year, showed 16% for Absorb versus 28.1% for XIENCE (adjusted p-value 0.0001).(20)
In addition to the long-term clinical benefits, Absorb may offer economic benefits over current metallic stents:
- The potential lower angina rates could possibly lead to a reduction in diagnostic tests (including imaging such as multi-slice computed tomography, angiography), hospital readmissions and target lesion revascularisation rates(25,26)
- Absorb allows patients to be diagnosed, screened, and followed-up using non- or minimally-invasive techniques, which may deliver health care cost savings thanks to the absence of blooming artefacts observed with metallic stents(27,28)
- Absorb may allow patients requiring retreatment to undergo less costly repeat PCI procedures rather than expensive heart surgeries.(29,30)
With the societal health and economic burden of CAD set to increase, there is a requirement for the continued development of highly efficacious, minimally invasive and cost-effective techniques to manage this disease.
Tremendous progress has been made over the last 20 years. Currently, XIENCE is recognised as the DES gold standard and has shown to improve the quality of care, by reducing events such as stent thrombosis, death and myocardial infarction.(9) This, in turn, might lead to economic benefits associated with lower readmissions.
A new revolution has recently been introduced. The Absorb BVS is changing the landscape of PCI, by offering the advantages of XIENCE as well as the differentiated benefits associated with the fact that there is no permanent implant in the vessel.
XIENCE and Absorb are trademarks of the Abbott Group of Companies. These products are intended for use by or under the direction of a physician. Prior to use, it is important to read the package insert thoroughly for instructions for use, warnings and potential complications associated with the use of this device. Information contained herein is for distribution for Europe, Middle East and Africa ONLY. Please check the regulatory status of the device before distribution in areas where CE marking is not the regulation in force.
Endeavor Resolute is a trademark of Medtronic. Taxus Liberté is a trademark of Boston Scientific Corporation or its affiliates. Biomatrix is a trademark of Biosensors. Cypher is a trademark of Cordis, a Johnson & Johnson Company.
ABSORB Cohort B and ABSORB EXTEND are Abbott Vascular Sponsored Studies. COMPARE is an Investigator Sponsored Study. RESOLUTE All Comers is an Independent all comers trial sponsored by Medtronic. LEADERS is a Biosensors sponsored study. All drawings are artist’s representations only and should not be considered as an engineering drawing or photograph. Photo(s) on file at Abbott Vascular. For more information, visit our website at abbottvascular.com.
© 2014 Abbott. All rights reserved. 1-EH-1-4137-01 01-2014 Rev A.
A purchaser’s point of view
Henk Boogaers, Purchaser since 1992 for the Thoraxcentre, part of the University Hospital Rotterdam in the Netherlands
My work goes beyond the simple purchase of medical products. I am given the opportunity by the cardiologists to enable innovations by developing an acceptable financial strategy. The challenge in my work consists not only to come to market prices, but also to achieve an acceptable expenditure pattern in conjunction with controllers and insurance companies.
In this way, the Thoraxcentre was the first hospital that after years of research has taken the decision to use DES for 100% of its patients. The next step was to investigate Bioresorbable Vascular Scaffolds (BVS), which resulted in a current use of BVS in almost 20% of all PCI. And this, despite a significantly higher price, which is driven by the fact that the production of this latest development involves quite some manual high-precision work. Thanks to further growth and development, both in product offering and competitive tendering, these BVS will certainly contribute in the future to a high performance PCI treatment.
Patients have become very interested in Bioresorbable Scaffolds, driven by a belief in this new therapy and by the reports in the press and on the Internet. Another success story has been the development of TAVI (transcatheter aortic valve implantation). Partly thanks to advanced knowledge of these developments and collaboration with industry, this has now become a product no longer to be ignored.
Besides its first task of patient treatment, a University Hospital also has an important role in the training of new specialists and in conducting research. Through all these new developments and thanks to a very close collaboration with the cardiologists, it has become clear that a Purchaser, if he or she is properly involved in the procurement process, can be instrumental in gaining financial benefits. But also is able to come to strategic alliances, resulting in studies and publications that put a University Hospital on the world map.
Bioresorbable scaffolds and angina
Antonio Colombo MD Director, Cardiac Cath Lab and Interventional Cardiology Unit, EMO GVM Centro Cuore, Columbus and San Raffaele Hospital, Milan, Italy
Regarding the topic of post-stent angina, there are some early observations reporting that this phenomenon is less prominent with bioresorbable scaffolds.
Let us first examine what post-stent angina, or better defined post-stent chest pain, is.
One patient out of five complains of ‘on and off chest pain’ for a few days after stent implantation. When the patient is evaluated, the chest pain is most of the time (>90%) not caused by ischaemia and the problem resolves spontaneously after a few days. Presently we do not have a clear explanation for this post-stenting chest pain. Nevertheless, few hypotheses have been generated: stretching of the artery by the metallic stent and changing the conformation of the vessel by introducing an element of rigidity with the elimination of natural shape of the artery are the most frequently cited explanations.
Many interventionists noticed that following implantation of a bioresorbable vascular scaffold, the problem of post-stenting chest pain is less frequent, not as intense and of shorter duration. Currently we have only speculations to explain this interesting observation. Possible explanations are:
- The bioresorbable scaffold has a slightly larger surface area which reduces the pressure exerted on the vessel wall, potentially minimising vessel injury
- The better conformability of the bioresorbable scaffolds distorts to a lower degree the natural anatomy of the vessel decreasing the wall stress and distributing the shear stress in a way closer to baseline.For practical reasons, the fact that patients who have been treated with a bioresorbable stent will experience post-stent chest pain in a lower percentage and severity has important practical implications.These complaints frequently lead to immediate medical attention and not infrequently to repeat hospitalisations, with performance of a number of non-invasive tests and the possibility that patients may undergo a repeat coronary arteriography. These actions generate anxiety, time loss and additional costs on the part of health providers.________________________________________________________________________References
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- The Economic Intelligence Unit. Succeeding in a value-based environment. White Paper, January 2014.
- Patient numbers based on 74 trials wordwide. See also http://clinicaltrials.gov/.
- Palmerini T et al. Clinical outcomes with drug-eluting and bare metal stents in patients with ST-segment elevation myocardial infarction: evidence from a comprehensive network meta-analysis. JACC 2013;62:496–504.
- Bangalore S et al. Bare metal stents, durable polymer drug eluting stents, and biodegradable polymer drug eluting stents for coronary artery disease: mixed treatment comparison meta-analysis, BMJ 2013;347: f6625 doi10.1136/bmj.f6625.
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- Palmerini T. Clinical outcomes with bioabsorbable polymer-based versus durable polymer-based drug-eluting stents and bare metal stents: evidence from a comprehensive network meta-analysis. JACC 2013; doi: 10.1016/j.jacc.2013.09.061.
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- Trybou J et al. Costs associated with readmissions in Belgian acute-care hospitals. Acta Clinica Belgica 2013.
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- Windecker S et al. Biolimus-eluting stent with biodegradable polymer versus sirolimus-eluting stent with durable polymer for coronary revascularisation (LEADERS): a randomised non-inferiority trial. Lancet 2008;372:1163–73.
- Kedhi E et al. Second-generation everolimus-eluting and paclitaxel-eluting stents in real-life practice (COMPARE): a randomised trial. Lancet 2010;375(9710):201–9.
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- Silber S et al. Unrestricted randomised use of two new generation drug-eluting coronary stents: 2-year patient-related versus stent-related outcomes from the RESOLUTE All Comers Trial. Lancet 2011;377(9773):1241–7. The number 22 is derived by calculating the largest difference versus Xience, that is, the taxus number. This difference of 2.2% (2.7%–0.5%) is then multiplied by 1000 patients.
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- Chevalier B. ABSORB cohort B trial evaluation of the Absorb everolimus eluting bioresorbable vascular scaffold (Absorb) in the treatment of patients with de novo native coronary artery lesions. 4-Year clinical results of cohort B1. TCT 2013.
- External market research: Ipsos Vantis Global ABSORB study, 2011. Data on file at Abbott Vascular.
- Patient numbers based on patients enrolled in ABSORB Cohort A, ABSORB Cohort B, ABSORB Extend, ABSORB II, ABSORB FIRST, ABSORB III and ABSORB China up until February 16, 2014.
- Patient numbers based on 17 studies worldwide. See also http://clinicaltrials.gov/.
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