Possible Turf War Brewing Over Delivery of Acute Stroke Interventions
Positive results with endovascular treatment for acute ischemic stroke—particularly mechanical thrombectomy with stent retrievers—flooded in this year, marking a “watershed moment in the field,” according to one expert. But while that’s great news for patients needing urgent care, it poses major questions for clinicians, namely, who will deliver the interventions and where?
There’s general agreement that skilled neurointerventionalists are best suited to perform endovascular stroke treatments, but a perceived manpower shortage in that area has led some to advocate for getting interventional cardiologists involved.
“I think it’s something cardiologists should embrace, not because we need to take over other people’s domains but because we’re in the perfect position,” David Hildick-Smith, MD, an interventional cardiologist at Royal Sussex Brighton Hospital (Brighton, England), told TCTMD, pointing to the 24/7 coverage already provided for emergency cardiac care. “I just don’t see anybody else being able to offer this service.”
Hildick-Smith said he anticipates “a bit of a turf war over it in one form or another,” and indeed, there was much skepticism about the need for interventional cardiologists coming from some already involved in acute stroke care.
“Stroke procedures really ought to be performed at comprehensive stroke centers where patients have access to the full range of stroke services, because there’s so much more to the treatment of stroke than a procedure alone,” Philip Meyers, MD, a neurointerventionalist at Columbia University Medical Center (New York, NY) and past president of the Society of NeuroInterventional Surgery, said in an interview. “This has to be the focus of acute stroke care, and I’m not sure everyone appreciates that yet.”
Before publication of the MR CLEAN trial results in December 2014, adding endovascular therapy to IV thrombolytic therapy had not been proven effective for patients with acute ischemic strokes. MR CLEAN was a positive trial, however, and the findings were supported 3 others presented at the International Stroke Conference in February—ESCAPE, EXTEND-IA, and SWIFTPRIME—and then REVASCAT in April. All showed that endovascular therapy—primarily with stent retrievers—improved outcomes in patients with large proximal intracranial occlusions.
The better outcomes seen in the recent trials were a consequence of using advanced imaging to select patients most likely to benefit and improved devices, according to Christopher White, MD, an interventional cardiologist at Ochsner Medical Center (New Orleans, LA) and a past president of the Society for Cardiovascular Angiography and Interventions.
In June 2015, the American Heart Association and American Stroke Association used the new trial data to update their acute ischemic stroke guidelines, which now back the use of stent retrievers in select patients while keeping IV tPA as the “mainstay of early treatment of acute ischemic stroke.”
The guidelines also state that “endovascular therapy requires the patient to be at an experienced stroke center with rapid access to cerebral angiography and qualified neurointerventionalists.”
Who Should be Delivering Stent Retrievers?
White told TCTMD that interventional neuroradiologists are probably the ideal clinicians to be treating stroke patients with stent retrievers, but said that there are not enough of them to meet the demand and provide the needed around-the-clock coverage. That manpower shortage can be addressed by tapping into the systems set up by interventional cardiologists for emergency cardiac care, White said.
He said that interventional cardiologists who have competency in carotid artery stenting already have the basic skills necessary to deliver stent retrievers and that partnering with neurologists removes the need for extensive training before starting to deliver acute stroke interventions. At Ochsner for example, a neurologist goes into the cath lab with the interventional cardiologist for each case, handling all neurological decision making while the cardiologist removes the clot.
“The criticism of cardiologists is that they don’t know enough neurology, but you don’t need to if you bring a neurologist with you,” White said. “So if you give me a neurologist and an interventional cardiologist, basically they make an interventional neuroradiologist.”
Anthony Gershlick, MBBS, an interventional cardiologist of the University Hospitals of Leicester NHS Trust, Glenfield Hospital (Leicester, England), told TCTMD that even though interventional cardiologists could easily perform the procedure, which is technically straightforward, that is where their involvement in the care of the patient would end.
Stroke patients require much in the way of neurological evaluation and care, and that requires a neurologist or neuroradiologist, he said. How interventional cardiologists would be involved in acute stroke care differs from how they are involved in primary PCI in that they can bring a background knowledge of the various factors influencing a cardiology patient to primary PCI, he said. “They can’t bring any of that to the management of a stroke patient because they’re not trained in stroke management,” he said. “We shouldn’t get confused. This is not the same as primary PCI.”
Nevertheless, if there are not enough neurointerventionalists to perform the required procedures, interventional cardiologists can fill the void, Gershlick said. “If that’s what the system demands and that’s what the cardiologist is happy to do, then so be it.”
L. Nelson Hopkins, MD, a neurosurgeon at the University at Buffalo (Buffalo, NY), told TCTMD that patients should be treated at comprehensive stroke centers by skilled neurointerventionalists if they are close enough. In areas where there is not ready access to such care, however, alternative plans, including treatment by interventional cardiologists before transfer to a comprehensive stroke center, need to be explored, he said.
“One of the things that I think we should push for and hope for is more collaboration among the different specialties,” Hopkins said, noting that it would be very challenging for 1 or 2 neurointerventionalists at a medium-sized center to be on stroke call every other night. In those situations, interventional cardiologists could join the stroke team and be taught how to deliver stent retrievers by the neurointerventionalists.
“I think if we developed a really good and rigorous training program, you could train cardiologists in a matter of weeks” and prepare them to handle any complications that are likely to occur, Hopkins said.
Not So Fast
Others, like Larry Goldstein, MD, a stroke neurologist at the University of Kentucky (Lexington, KY), are more circumspect when it comes to interventional cardiologists treating acute stroke, however.
“It’s not just being able to put a catheter into an artery,” Goldstein said, highlighting the years of neurology-specific training required to establish a baseline level of competency, an understanding of the disease process, and a grasp on the best approaches to treating stroke before acquisition of the technical skills.
Currently, acute stroke interventions are delivered primarily by interventional neuroradiologists, interventional neurologists, and interventional neurosurgeons who have that level of training. If there were a way to provide all of that training to interventional cardiologists, then it might be a reasonable approach to get them involved, Goldstein said.
David Chiu, MD, a neurologist at Houston Methodist Hospital (Houston, TX), agreed that specialized training would be necessary for interventional cardiologists. One should not assume “that doing X number of cases of coronary stenting means that you can just do the same procedure in the intracranial vessels,” he said, pointing out that intracranial procedures have much higher rates of complications than coronary or carotid procedures.
From the cardiologist’s perspective, Hildick-Smith estimated that interventional cardiologists would probably need to do about 50 cases with a neurointerventionalist and attend courses to understand the intracranial anatomy and differences in vessel structure and function and to learn about the types of tools used in neurointerventional procedures in order to get started with acute stroke interventions.
It remains unclear, Goldstein said, whether patient outcomes would suffer without operators having extensive neurointerventional training and/or with a system of interventional cardiologists treating patients and then transferring them to a comprehensive stroke center.
Some patients cannot be transferred after a stroke and need immediate neurological intensive care, he said, adding that performing thrombectomy without additional support could cause more harm than good.
Outcomes Appear Comparable
Although there are few data to inform the issue, White pointed to a study performed at his center to support the idea that interventional cardiologists can get patient outcomes as good as those achieved by neurointerventionalists. The study, published in December 2014, showed that there were no differences between the 2 types of operators in the likelihood a good neurologic outcome (modified Rankin Scale ≤ 2), death during the index hospitalization, 30-day mortality, mean NIH Stroke Scale score, lesion type, periprocedural complications, or postintervention TICI ≤ 2 flow for patients undergoing catheter-based therapy for acute ischemic stroke.
But those findings did not convince Meyers that outcomes are similar across operator types. When the results were published, he told TCTMD that “this is more a political statement than a scientific manuscript. While the authors speak to a multidisciplinary stroke team approach at Ochsner, it is surprising that only cardiologists authored this manuscript.
“We have entered the era of large multicenter randomized trials,” he continued, adding that “publication of single-center, nonrandomized, nonadjudicated data is not constructive.”
Something else to be considered, Meyers said, is that if the pool of eligible operators is increased dramatically then it will be difficult for any neurointerventionalist or interventional cardiologist to accumulate a sufficient number of thrombectomy procedures to maintain competency and that, too, could adversely affect patient outcomes.
Willingness to Participate
Gershlick said the willingness of interventional cardiologists to get involved in delivering acute stroke interventions will vary, with some resisting because of an already loaded schedule, some wanting to become engaged, and others signing on for an opportunity to make more money.
“I’m not sure that there will be that many who will be keen,” he said. “I think when they do appreciate that they’re mainly technicians, then some of the enthusiasm may wane a bit.”
Whether interventional cardiologists could increase their workloads to accommodate the added responsibilities would vary depending on the situation in specific health systems, but many would want to participate after seeing the benefits for patients, according to Hildick-Smith.
“The potential for doing good is just enormous so I think anybody who got involved in that and saw the potential result of a good case would immediately be inclined and interested to consider offering that service,” he said.
A major issue will be organizing a 24/7 service that works for everybody involved in treating acute stroke, Hildick-Smith said.
“I would personally like to see a vascular emergency team develop which incorporates cardiologists, neurointerventionists, and vascular radiologists,” he said, noting that neurointerventionalists could learn how to do emergency coronary cases and cardiologists could learn how to perform emergency neurovascular cases. “Each of us deals with the emergencies overnight and then during the day does our own area of personal expertise.”
Cardiologists Likely to Become Involved
Hildick-Smith said that there has not been pushback on the idea of interventional cardiologists helping with acute stroke from the neurointerventionalists at his center, who have said only that cardiologists are overestimating the demand for endovascular stroke treatments.
Meyers remains skeptical of the need for interventional cardiologists in acute stroke care and said that there is a sufficient number of neurointerventionalists to meet the existing demand. The focus, he said, should be on developing a stroke network designed to provide access to acute care delivered by skilled operators.
“Our stroke network should be built on the trauma network model,” he said. “Rather than a land rush, where there’s a rush to stake out territory, I just think the American population ultimately would benefit more by having experts perform stroke care.”
Nonetheless, Meyers said he does think that interventional cardiologists will have a role in delivering acute stroke interventions in the coming years, pointing to financial incentives for operators and manufacturers of the devices as a contributing factor.
“I think there are several ways that stroke care can develop. It will largely depend on the forces that direct the development,” he said. “We can scale stroke systems in a systematic manner according to local and regional needs, or we can allow free market enterprise to define the efficiencies. Economists can debate the merits. There is no doubt that the private sector has played an active, even leading, role in development of new technologies to treat stroke patients. Nevertheless, I believe that the public health will best be served by a rational approach to system design for stroke care. It offers our best chance to ensure quality care in a programmatic manner.”
- Chiu, Gershlick, Goldstein, Hildick-Smith, Hopkins, Meyers, and White report no relevant conflicts of interest.