health care

Lina Palaiodimou, MD

Lip GYH, Keshishian A, Li X, Hamilton M, Masseria C, Gupta K, et al. Effectiveness and Safety of Oral Anticoagulants Among Nonvalvular Atrial Fibrillation Patients: The ARISTOPHANES Study. Stroke. 2018

The ARISTOPHANES study is a large retrospective observational study with real-world data pooled from 5 data sources in the United States, in order to compare stroke/systemic embolism (SE) and major bleeding (MB) among nonvalvular atrial fibrillation patients treated with either non-vitamin K antagonist oral anticoagulants (NOACs) or warfarin.

The researchers of this study collected data about a total of 321182 patients with a diagnosis of AF, who had an active medical and pharmacy health plan enrollment and were prescribed treatment with either NOAC or warfarin according to pharmacy claims. Exclusion criteria were the following: evidence of valvular heart disease, venous thromboembolism, previous oral anticoagulant treatment, transient AF due to treatable causes (pericarditis, hyperthyroidism, thyrotoxicity), heart valve replacement or transplant, pregnancy and recent surgical operations. Demographic data, Charlson Comorbidity Index score, baseline bleeding and stroke/SE history, comorbidities, baseline comedication and dose of NOAC were recorded about all patients. In contrast, reason for lose-dose NOAC prescription, creatinine clearance, international normalized ratio (INR) measurements in warfarin-treatment group and patient adherence data were not available. The outcome measures were time to stroke (either ischemic or hemorrhagic) or systemic embolism and time to major bleeding, either gastrointestinal or intracranial or at other key sites (eyes, pericardium, urinary tract, joints). Identification of these events were based just on hospitalization incidence with stroke/SE or MB as the principal diagnosis according to International Classification of Diseases, Ninth Revision (ICD-9). Mortality due to all-causes was also evaluated, but just for the patients enlisted in only one out of five data sources. Patients were followed up each for a different period, according to drug discontinuation date, switch to another drug date, death, end of medical and pharmacy health plan enrollment, or end of study period, whichever occurred first. In the conducted sensitivity analysis, the follow-up period was restricted to 1 year, to better achieve balance between the cohorts.

Kevin S. Attenhofer, MD

Dijkland SA, Voormolen DC, Venema E, Roozenbeek B, Polinder S, Haagsma JA, et al. Utility-Weighted Modified Rankin Scale as Primary Outcome in Stroke Trials: A Simulation Study. Stroke. 2018

As stroke neurologists, we are all intimately familiar with the modified Rankin Scale (mRS) as a measure of degree of disability. It is a common outcome measure in stroke research and can be statistically analyzed as a simple dichotomization or ordinal shift (among other options). The dichotomized outcome takes varied and complex neurological outcomes and simplifies them down to nominal variables of “good” or “bad.” This is statistically more straightforward, but does result in some outcome information being discarded. The ordinal shift retains more of this information, but typically requires larger sample size to maintain adequate power. Even when well powered, however, the mRS still has a disproportionate focus on motor function when compared to other neurological domains, such as cognition or patient metrics such as quality of life.

Neal S. Parikh, MD 
@NealSParikhMD

Dozois A, Hampton L, Kingston CW, Lambert G, Porcelli TJ, Sorenson D, et al. PLUMBER Study (Prevalence of Large Vessel Occlusion Strokes in Mecklenburg County Emergency Response). Stroke. 2017

Optimizing access to endovascular therapy has become a public health priority. While various national guidelines seek to shape acute stroke EMS triage practices broadly, regulatory bodies have also acknowledged the need to tailor protocols to local and regional environments.

In deciding whether to triage an individual patient with suspected stroke to an endovascular center instead of a primary stroke center, EMS may consider factors such as relative travel distances, stroke severity, and the likelihood of a large vessel occlusion (LVO).

LVO screening tools have inherent imprecision, and the positive predictive value, of course, depends on the prevalence of LVO. For this reason, knowing the prevalence of LVO among acute ischemic stroke 9-1-1 dispatches is of importance. Further, at an organizational level, the accuracy and precision of LVO detection in the field has upstream implications for case load at endovascular and non-endovascular centers. The importance of these considerations varies by locale.

Abbas Kharal, MD, MPH, and Richa Sharma, MD, MPH

Jagolino-Cole AL, Bozorgui S, Ankrom CM, Bambhroliya AB, Cossey TD, Trevino AD, et al. Benchmarking Telestroke Proficiency: Page-to-Needle Time Among Neurovascular Fellows and Attendings. Stroke. 2017

Telestroke management is built into the curriculum of many vascular neurology fellowships and affords fellows (NVF) the opportunity to achieve proficiency in this modality. This study demonstrates that the page-to-needle time, or PTNT, is higher among NVFs compared to NVAs. As a result, the authors are suggesting that PTNT is a metric of proficiency. Given lower PTNT among NVAs compared to NVFs, there is an assumption that further training may decrease PTNT and, transitively, increase proficiency. As such, there may be a benefit in greater emphasis of dedicated telestroke training during fellowship.

There is an inherent truth in the logic that additional training can result in decreased PTNT just by sheer procedural repetition to learn the logistics of data-gathering by the phone, video, and imaging from an outside institution. However, perhaps the process is also faster for NVAs compared to fellows due to the attendings’ greater body of experiences seeing numerous patients with each stroke syndrome, treating them acutely, and then following the clinical course in the rehabilitation and subacute phase. Thus, proximal care of stroke patients longitudinally may aide in faster decision-making for remote, telestroke patients. Given that most vascular neurology fellowships are only one clinical year, it is thus critical that telestroke training does not supersede rotations, which require direct patient contact throughout the spectrum of the disease, since it is this contact which informs the decision-making process in the practice of telestroke.