The argument for training interventional cardiologists to work in the brain
Faced with a shortage of specialized stroke neurologists in the U.S., some proposed that other interventionists get extra training so they can step in and perform endovascular stroke treatment in places that lack access to this therapy.
"In rural areas and in small- to medium-sized communities without CSCs [comprehensive stroke centers] or 'stroke-ready' teams, skilled extracranial interventionists can play a critically important role in stroke intervention," according to David Holmes, Jr., MD, an interventional cardiologist at the Mayo Clinic in Rochester, Minnesota, and L. Nelson Hopkins, MD, a neurosurgeon at the University at Buffalo, New York.
There are only 800 to 1,100 neurointerventionalists across the country but nearly 10,000 interventional cardiologists, radiologists, and vascular surgeons who could expand future stroke teams, Holmes and Hopkins said in their review article published in the April 2 issue of the Journal of the American College of Cardiology (JACC).
"What is required is a willingness on the part of the neurointerventional community to train interested interventional cardiologists, radiologists, and vascular surgeons in stroke intervention, incorporate these interventionists into stroke teams, and make interdisciplinary collaboration the norm for this compelling public health issue," they emphasized.
Are The Skills Transferable?
Studies have shown that teams of neurologists and carotid stent-capable interventional cardiologists can together help acute stroke patients achieve outcomes that are not inferior to those from neurointerventionalists working at urban medical centers, as Christopher White, MD, an interventional cardiologist at Ochsner Medical Center, New Orleans, wrote in the same JACC issue.
A recent study also found that interventional radiologists learning from a neurointerventionalist achieved a technical success rate of 83% in their first 35 cases of mechanical thrombectomy.
"Interventional cardiologists, interventional radiologists, and interventional vascular surgeons must learn the basics of anatomy, pathophysiology, diagnosis of ELVO [emergent large vessel occlusion], neurotechnology, and methodology if they have interest in joining a stroke intervention team," Holmes and Hopkins cautioned.
But once the cerebrovascular skills are there -- for arterial vascular access, negotiating the aortic arch, and selective cannulation of the internal carotid artery -- it shouldn't be an issue whether the procedure is carotid stenting or mechanical thrombectomy of large vessel occlusion, White wrote.
Currently, these endovascular procedures are mostly being done by neurologists, neurosurgeons, and radiologists who follow certain standards in neuro-endovascular techniques in stroke intervention.
Interventional cardiologists may be able to perform these techniques, but it's "not a simple translation" from the cardiac blood vessels to brain blood vessels, argued Mitchell Elkind, MD, MPhil, a stroke neurologist at NewYork-Presbyterian Hospital in New York City.
In the last 5 to 10 years, more neurologists and neurosurgeons have joined the ranks of those who can perform these procedures as there are efforts to involve those who already have specific training in neurology, Elkind told MedPage Today. "Specialized training usually involves some training in neuro-critical care and stroke neurology, and then practical training in performing endovascular procedures under the mentorship of an experienced practitioner for at least 2 years."
White said he would agree with neuroradiologists who argue that they are the best at performing mechanical thrombectomy.
After all, endovascular volume does correlate with patient outcomes, as there is a greater 30-day mortality risk at low-volume facilities, a representative for the Society of NeuroInterventional Surgery pointed out when asked for comment.
"As conversations about providers of endovascular stroke therapy continue, it is important to note that nearly all of the cases enrolled in the ESCAPE and DAWN trials that demonstrated the benefit of thrombectomy were performed by formally trained neurointerventionalists who maintain high caseload volumes. We simply do not know if the research outcomes from ESCAPE and DAWN would be the same had the procedures been done by physicians without formal neurointerventional training and high caseload volumes," according to a statement from the group.
What Does This Mean for Access to Care?
The issue is access. Only 56% of the U.S. population could get to a CSC in under an hourby ground transport, according to a study from 2014.
"Even assuming an unrealistic addition of 20 optimally located CSCs per state, one-third of stroke patients would still be left without 1-h ground access for care," White noted.
Yet whether any new extracranial interventionists even have room to play a role in endovascular stroke therapy depends on the needs of each institution.
"[Neurointerventionalists] don't want to enable less-experienced individuals in their medical center to battle for these patients. But I don't think that's a realistic concern because, at least in my experience, that never happens," White said in an interview, adding that his center only trained interventional cardiologists to perform these procedures when there was just one neurointerventionalist on board. "Now we have three and they don't need us anymore."
"The thing to remember about this is that acute stroke intervention is not a high-volume procedure, and no one does a lot of these -- even neurointerventionalists," White said. "It's never going to be anyone's core business."
Large centers with multiple neurointerventionalists who are able to staff the laboratories all the time are probably not going to need more extracranial interventionists, according to Holmes and Hopkins.
But, they added, "as stroke intervention becomes more mainstream, especially when regulators begin to impose the door-to-needle mandates that are now common for STEMI, having additional trained physicians on the interventional stroke team including appropriately trained extracranial interventionists could be a welcome addition."
Those trying to improve access to care should consider not just increasing the workforce, but ensuring that endovascular therapy is done in places where the people are adequately trained, Elkind emphasized.
"I think it's a great opportunity for people who are interested in neurological disease to get involved in these procedures. But it's something that needs to be done properly and people can't simply assume that they can extrapolate doing this procedure from other parts of the body to doing it in the brain."
Holmes disclosed no relevant conflicts of interest.
Hopkins reported grant/research support from Canon Medical Systems Corporation; financial interests/stock in Boston Scientific, Cerebrotech, EndoStream, Endomation, Silk Road, the Ostial Corporation, Imperative Care, StimSox, Photolitec, ValenTx, Ellipse, Axtria, NextPlane, and Ocular; and has a board/trustee/officer position in Imperative Care.
Journal of the American College of Cardiology
Source Reference: Holmes DR, Hopkins LN "Interventional cardiology and acute stroke care going forward: JACCreview topic of the week" J Am Coll Cardiol 2019; DOI: 10.1016/j.jacc.2019.01.033.
Journal of the American College of Cardiology
Source Reference: White CJ "Acute stroke intervention: the role of interventional cardiologists" J Am Coll Cardiol 2019; DOI: 10.1016/j.jacc.2018.12.071.
Read the original article on Medpage Today: Skip the Turf Wars, Improve Endovascular Stroke Therapy Access?