ONGOING. The world’s largest randomized study of the invasive treatment of atherosclerosis is currently being carried out in Sweden. Sahlgrenska Academy’s Institute of Clinical Sciences is spearheading the project, which is being financed through the Swedish Research Council’s Fund for Clinical Therapy Research.
Atherosclerosis causes intense pain to those who suffer from the disease. Amputation is sometimes necessary. Common invasive treatments (surgical procedures) include balloon angioplasty of the “sick” blood vessel, sometimes supplemented with by the insertion of a stent (an expandable mesh cylinder). Many patients suffer from restenosis, which negatively affects the treatment outcome of the procedure.
Nearly 1200 patients have been randomly assigned to the SWEDEPAD study, a national register-based randomized trial being led by Sahlgrenska Academy’s Institute of Clinical Sciences. The study has its own website, which not only provides information to patients but also functions as a tool for participating clinics.
“A new and expensive technique has the potential to reduce the risk of amputation in patients with critical ischemia, and may also improve quality of life for patients with severe intermittent claudication. It may also reduce the risk of restenosis, by preventing the reconstruction of new occluding tissue. The treatment involves a procedure in which drug-eluting balloons and stents are inserted into the “stricken” vessel,” explains Associate Professor Mårten Falkenberg, of the University of Gothenburg’s Department of Radiology.
He and Dr Joakim Nordanstig are leading the study, in collaboration with a national steering committee. Both men are on the faculty of Sahlgrenska Academy – Mårten Falkenberg at the Institute of Clinical Sciences, and Joakim Nordanstig at the Institute of Medicine.
Registry-based research using randomization modules
However, to assess the effectiveness of this type of procedure and justify its additional cost, it is necessary to carry out comprehensive studies such as this one. In short, the objective of the study is to determine whether products that emit medications intended to affect blood vessel walls are superior to traditional treatments that do not involve this effect. By using the Swedish National Quality Registry for Vascular Surgery (SWEDVASC) and inserting a randomization module into the software, most Swedes who undergo a XLED vascular procedure can be evaluated as candidates for the study, and subsequently offered a place if they are deemed eligible.
“Our study is financed by the Swedish Research Council’s Fund for Clinical Therapy Research, and we plan to randomize a total of 3,733 patients. With 1200 patients to date, SWEDEPAD is already the largest randomized trial of the invasive treatment method of patients with arterial disease ever to be undertaken,” says Mårten Falkenberg.
Paving the way for safer research
In the medical community, there is currently considerable criticism regarding research into the usefulness of medical devices. These concerns stem from a lack of clear legal regulatory framework and resourceful governmental investigative authorities, compared with the guidelines and oversights imposed on pharmaceutical research. In an article published in the October 2016 edition of the Swedish medical journal Läkertidningen, chief physician Professor Henrik Sjövall addresses this issue. He writes:
“Happily, an extensive, well-designed, national comparative study (SWEDEPAD, NCT02051088) is currently underway, supported by funding from the Swedish Research Council. Hopefully, this study will answer the question of whether or not these products can generally benefit patients. Patients are equally divided into two study groups: those whose treatment involves drug-eluting balloons, and those treated using conventional, non-drug-eluting balloon dilation methods.”
“We will continuously monitor the treatment results, uploading them regularly to SWEDVASC. This information will be supplemented with data from patient medical records. An interim analysis will be made in about 12 months’ time and the results may affect the scope of the study,” elaborates Joakim Nordanstig.
Patient feedback – an important yardstick of success
Study participants must fill out several questionnaires, so as to measure the outcomes/results of their various treatments. Along with other evaluative resources, the VascuQoL-6 survey is being used to measure and assess health-related quality of life issues associated with vascular disease. An additional health-related questionnaire, EQ5D, is also being implemented, to help SWEDEPAD researchers make a health economic calculation regarding treatment methods and outcomes. This survey measures health outcomes from a patient perspective.
The study is the largest randomized trial of invasive treatment procedures for PAD, even by international standards.
“We believe there is a high degree of certainty that the results of this study will affect future treatment strategies for arterial disease and similar conditions, such as renal artery stenosis and stenosis in conjunction with arteriovenous fistulas,” opines Mårten Falkenberg.
- All adults > age 18 who are willing to participate in the study
- Symptomatic peripheral artery disease (critical ischemia or claudication) caused by > 50% stenosis or infrainguinal arterial occlusive disease, treatable using endovascular techniques (according to the established surgical indications)
The study’s website: http://www.ucr.uu.se/swedepad/
TEXT: SUSANNE LJUNGMAN WESTERGREN