Editor's Note: Do you refer stroke patients to registries? If not, why not? Do you agree with Dr. Connors' assertion that neurologists “do not believe in” interventions? Please write us at clinicalneurlogynews@elsevier.com
OLYMPIC VALLEY, CALIF. — Few neurologists have been enrolling patients in any of the three existing stroke registries, in large part because they do not know about them.
Dr. John J. Connors III, medical director of the NeuroVascular Research Foundation, noted that although many neurointerventionists may be aware of these registries, those who are on the front lines of stroke treatment are simply not aware of the registries or are reluctant to participate because of the time and diligence required. There are currently three registries enrolling patients.
The first, known as INSTOR (Interventional Stroke Therapy Outcomes Registry), was designed primarily to collect information on intra-arterial lysis for large-vessel occlusion. At first, 159 sites expressed interest in participating, but most have not entered any patients since INSTOR's launch in 2002. Nevertheless, 20 active sites have contributed 278 patients to date, making it the largest database in the world that focuses on this type of stroke treatment.
A second registry, INTRASTOR (Intracranial Angioplasty and Stenting Outcomes Registry), was created to evaluate whether angioplasty and stenting can prevent stroke by treating atherosclerotic disease in the brain. At a poster presented at the annual meeting of the Society of Neurointerventional Surgery, data from 199 patients with 201 lesions indicated that 89% (178) of patients had greater than 70% stenosis. In all, 90 patients were treated with angioplasty alone, 72 by primary stenting, and 29 by angioplasty followed by stenting. (Data were unavailable for the remaining eight patients.)
After treatment, 74% of patients had less than 33% residual stenosis, and 14% of patients had 34%–50% residual stenosis. Symptomatic complications included 10 patients with permanent neurologic deficits, 26 with minor complications that fully resolved, and 3 patients who died.
A third registry that was recently launched, known as INSTOR II, is designed to collect more complete information on the use of mechanical and combination interventions that are used to treat acute ischemic stroke. These interventions include mechanical retrievers and a device that delivers intracranial ultrasound-aided lysis.
“We need neurologists on board,” Dr. Connors said. “Although randomized control trial data are always preferable, any data are better than none. The INSTOR registries include [data on] patient selection, usually with [CT angiography] to choose patients with large-vessel occlusions. To this day, even with our ubiquitous neuroimaging tools, large stroke treatment trials [such as the Interventional Management of Stroke III trial] still use only patient selection no more sophisticated than that used 20 years ago. No oncology trial, for instance, would ever include all grades of breast cancer in a chemotherapy trial.”
Although larger numbers of patients are still needed, the registries are already revealing worthwhile information, Dr. Connors noted. For instance, the data from INSTOR I indicate that almost one-fifth of the 278 patient were on Coumadin, but 45 of these 53 patients had international normalized ratio levels lower than 2.0, indicating less-than-effective doses that might have allowed a cardiogenic embolus in a patient who was known to be at risk.
Other data suggest many of the patients were being treated with acetylsalicylic acid but had a presumed cardiogenic embolus and possibly should have been on Coumadin. Their average score on the National Institutes of Health Stroke Scale was 17, and 53% of patients had 3-month Rankin grades of 0–2 (though follow-up was incomplete).
“Registries are necessary for proof that neurointerventional procedures work. They are recommended by the Brain Attack Coalition in Comprehensive Stroke Centers. They are mandated by certain health care agencies, including the state of Florida, [and] by several medical societies, and will be mandated by upcoming stroke-treatment training guidelines. Decisions by [the Centers for Medicare and Medicaid Services] have been based upon registry data,” Dr. Connors said. “It is necessary for members of the endovascular societies that treat stroke to participate in this effort.”
Although most neurologists, particularly those in leadership, do not believe in these interventions, the data from the registries—if adequate numbers are achieved—should help remove any concerns that endovascular intervention for appropriately selected patients works.
“Collecting these data in the long run is beneficial for the science of endovascular stroke therapy and prevention, but requires the commitment of both individual physicians and medical leadership,” Dr. Connors said. In the long run, these data are good not only for the patient, but also for the cerebrovascular/stroke business, he added.