Bif-ARC
CORRIB Research Centre for Advanced Imaging and Core laboratory
In the beginning
The Academic Research Consortium (ARC) history began in 2007 with the release of the first ARC document, co-led by Patrick Serruys and Donald Cutlip, in collaboration with other colleagues: Stephan Windecker, Roxana Mehran, Gerrit-Anne van Es, Pascal Vranckx and Mitchell Krucoff, affiliated to diverse worldwide renowned Research Institutes. ARC is a collaboration across geographies and between Industry and Academia.
“One of the great debate at that time was to uniformize the definitions of stent thrombosis and the individual components of the major adverse cardiac events and it was the initial impetus to a long series of academic consensus”
Following that, a number of ARC consensus were developed within the ARC partnership: Valve-ARC (VARC), VARC-2, Paravalvular Leaks in Surgical Prosthesis (PVL ARC), Non-Adherence ARC (NARC), ARC-2, CTO-ARC, just to give few examples, to the very last one Bif-ARC.
What is an ARC document?
The main ARC goal is to create -through a published document- a dynamic, open-ended, transparent, collaborative forum across stakeholders, whose objective is to develop consensus definitions, nomenclature, and study endpoints, optimized and targeted for application in clinical trials of specific cardiology fields.
The ultimate mission of such documents is to align researchers and clinicians across different countries and health systems in order to standardize the research activities, making their outcomes comparable and generalizable as much as possible.
Why the Bifurcation-ARC document?
Along the lines of the previous ARC documents, the Bif-ARC project originates from the need to overcome the paucity of standardization and definition and to foster comparability between studies involving bifurcation coronary lesions.
Yves Louvard
Yves Louvard
The European Bifurcation Club that celebrates its 20th anniversary of existence have been struggling all these years against the lack of rules in trials comparing technique and devices despite formidable progresses in the knowledge of the field.
Bifurcation lesions are considered peculiar coronary lesions, because of their anatomical complexity, making them different from any other “normal” coronary lesions, in terms of definitions, classifications, diagnosis, treatment, and follow-up.
Despite previous efforts from Bifurcation societies (for example the European ,the SCAI and the Bifurcation Asian Clubs), nowadays too much variability exists between clinicians and researcher’s approach when dealing with such a kind of anatomic lesion.
As a consequence operators-, or centers-, act mostly according to experienced-based decisions and can not rely on evidence based-standardized guidance, eventually impacting the patient’s outcome.
Donald Cutlip
Donald Cutlip
The mission of ARC is consensus and collaboration to standardize definitions for investigators, regulators, and industry sponsors. This bifurcation effort supports that mission in an unmet area of coronary intervention and will improve clinical investigation and patient care for bifurcation disease.
What is addressed in the Bif-ARC?
Bifurcation lesions require specific definitions, guidance and rules of engagement consensually accepted by a large community of experts. This is what Bif-ARC encompasses.
“Pragmatic consensus definitions promote consistency and thus the quality of benefit/risk evidence – especially safety evidence -- across cardiovascular device trials. This is the a priori principle and mission of the Academic Research Consortium”
Mitchell Krucoff, Duke University Medical Center and Roxana Merhan, Mount Sinai.
Mitchell Krucoff, Duke University Medical Center and Roxana Merhan, Mount Sinai.
The document begins clarifying what is a bifurcation lesion, which are its anatomical components, how to define them, and how to classify the bifurcation lesion.
Many years ago Alfonso Medina designed a simple, pragmatic classification, swiftly adopted by the interventional community; to date the classification has been rejuvenated and strengthened by invasive and non invasive imaging
Thierry Lefevre, Institut Cardiovasculaire Paris Sud.
Thierry Lefevre, Institut Cardiovasculaire Paris Sud.
Olivier Darremont, Clinique St Augustin. Bordeaux
Olivier Darremont, Clinique St Augustin. Bordeaux
These definitions are a good springboard for further standardization and target for objective quantification. Indeed, many operators still use their visual/subjective assessment of bifurcation lesion and the variability of assessment is a confounding factor.
Such concepts are very useful and applicable not only in the research setting, but also in the routine clinical practice.
Following the description of these definitions , the document discusses for the very first time a KEY POINT in the field of bifurcations, which has been debated for many years without any consensus: the relevance of the Side Branch.
The Side Branch is simply the smallest branch of the two daughter branches stemming from the mother vessel. Sometimes this branch is really small, and therefore too insignificant, to worth any attention of the operator, and in these cases, the treatment of the side branch can be neglected because the “collateral damage” imparted to the side branch , resulting from the dilatation of the main branch will be trivial. But if the Side Branch is quite relevant from a physiological and clinical view point, we need to take care of it and the treatment of the bifurcated lesion becomes more complex and challenging.
Less is frequently more in bifurcation treatment
The big issue, so far, was that there was no criteria, to define the clinical “relevance” of a Side Branch.
In this document, the authors underscore the concept of clinical relevance, highlighting its importance for the welfare and the prognosis of the patient. A dedicated algorithm is proposed to decide whether a Side Branch should be considered relevant or not. The algorithm is based on specific diagnostic investigation, and the best feature of this algorithm is its practicality. Indeed, there are different diagnostic and prognostic criteria according to the type of diagnostic investigation used or available in a clinical center. Not all centers have, in fact, coronary CT, nuclear imaging, stress cardiac MRI, ect…, but thanks to this flow-chart we can define a Side Branch relevance also on the sole base of a diagnostic angiogram.
Over the last decade interventional cardiologist have realized that their technical act must be justified by a real short and long term benefit for the patient
Bon-Kwon Koo, Seoul National University Hospital
Bon-Kwon Koo, Seoul National University Hospital
How does Bif-ARC support the future research on bifurcations?
The above-mentioned concepts are easily applicable either to clinical practice or to the research studies.
Further on, the document goes through the definitions of the different potential types of Trials about bifurcations.
This is another key aspect of the document.
Six different classes of studies, indeed, are proposed: First in Man studies, comparison of percutaneous treatments, comparison of different devices, comparison of diagnostic techniques, comparison of revascularization strategies, and pharmacological studies. Indeed, each class have dedicated Endpoints (single and composites), according to what is under investigation.
Classifying a new bifurcation study in one of this category will be fundamental.
Goran Stankovic, University Clinical Center of Serbia
Goran Stankovic, University Clinical Center of Serbia
In conclusion
The last very important topic explored in the document is how to perform the follow-up after a bifurcation revascularization. This is often a hot topic, that created confusion and probably biased the interpretation of some trials results. Indeed, the type and the timing of the follow up is crucial when the researcher collects and analyses the results of a study. In some occasions, previous studies provided an invasive (angiography) follow up before assessing the clinical status of a patient, resulting in non clinically indicated repeated revascularizations, only driven by the so called “oculo-stenotic reflex” of the operator, while maybe the patient was totally asymptomatic and above all no ischemia would have been detected.
The Bif-ARC suggests rules to perform the right type of follow-up (invasive, non-invasive, patient-reported) at the right moment, to avoid as much as possible potential confounding factors.
Yoshi Onuma and Mattia Lunardi have been very instrumental in collecting and coordinating the opinions stemming from different parts of the world.
Yoshi Onuma, National University of Ireland, Galway
Yoshi Onuma, National University of Ireland, Galway
Mattia Lunardi, National University of Ireland, Galway
Mattia Lunardi, National University of Ireland, Galway
We have been amazed by the richness and diversity of point of views that reflect the complexity of the treatment and the need to fix what we call the rules of engagements when designing a trial”.
The future will tell us whether the community of practitioners, investigators and trialists will embrace these recommendations and whether research and clinical practice, thereby our patients will benefit of Bif-ARC
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