Monthly Archives: April 2019

Victor J. Del Brutto, MD

Kim D, Park JM, Kang K, Cho YJ, Hong KS, Lee KB, et al. Dual Versus Mono Antiplatelet Therapy in Large Atherosclerotic Stroke: A Retrospective Analysis of the Nationwide Multicenter Stroke Registry. Stroke. 2019;50:1184–1192.

Large artery atherosclerosis (LAA) is responsible for a fourth of all ischemic strokes and is the mechanism of cerebral ischemia with the highest risk of recurrence. Current evidence supports that aggressive platelet anti-aggregation is beneficial in the acute phase due to the high thrombogenicity caused by plaque rupture, while the use of statins and strict vascular risk factors control is more relevant chronically to assure plaque stability and to stop arterial disease progression. Current guidelines recommend long-term antiplatelet monotherapy for secondary stroke prevention. However, high-risk clinical settings such as coexistence of coronary artery disease, stroke recurrence despite taking one antiplatelet agent, high-degree stenosis, or presence of micorembolic signals on transcranial Doppler often lead physicians to prescribe dual antiplatelet therapy (DAPT) beyond the acute phase.

The current study used a large multicenter prospective stroke registry from Korea to compare the effectiveness of DAPT with clopidogrel plus aspirin versus aspirin monotherapy in preventing vascular events and death in patients who had an ischemic stroke or TIA attributed to LAA. At one-year follow up, combination therapy was associated with lower risk of having the composite outcome of any stroke, myocardial infarction, or all-cause death. Of notice, DAPT did not reduce the risk of stroke recurrence when compared to aspirin alone, thus results were mainly attributable to overall mortality reduction (Figure 4).

Figure 4. Kaplan-Meier curves for primary outcome (A), stroke recurrence (B), and all-cause death (C) after stabilized inverse probability of treatment weighting in intention-to-treat, per-protocol, and as-treated populations. A indicates aspirin; and C+A, clopidogrel plus aspirin.

Kara Jo Swafford, MD

Wysocki NA, Bambhroliya A, Ankrom C, Vahidy F, Astudillo C, Trevino A, et al. Outcomes Among Patients With Ischemic Stroke Treated With Intravenous tPA (Tissue-Type Plasminogen Activator) via Telemedicine: Is the Drip-and-Stay Model Safe? Stroke. 2019;50:895–900.

Telemedicine has expanded patient access to acute stroke treatment, including administration of intravenous (IV) tPA. It supports the “hub and spoke model,” providing immediate patient access to a stroke specialist at a remote hospital to help guide emergent treatment. After initial telemedicine consultation and administration of IV tPA, whether the safety and outcomes of transferring the patient to the hub hospital (“drip-and-ship”) or remaining at the spoke hospital (“drip-and-stay”) are similar is uncertain.

Wysocki et al. conducted an observational retrospective review of prospectively collected data from a telemedicine stroke registry. The study included patients with acute ischemic stroke who received IV tPA at one of 17 network hospitals and then either stayed or were transferred to the hub hospital. Those who had planned endovascular therapy were excluded because all were transferred to the hub hospital. Primary outcomes included in-hospital mortality, length of stay, discharge disposition, rates of symptomatic ICH, and good functional outcome based on achieving a 90-day mRS score of 0-1.

Danielle de Sa Boasquevisque, MD

Boeckh-Behrens T, Pree D, Lummel N, Friedrich B, Maegerlein C, Kreiser K, et al. Vertebral Artery Patency and Thrombectomy in Basilar Artery Occlusions: Is There a Need for Contralateral Flow Arrest? Stroke. 2019;50:389–395.

Patients with basilar artery occlusion (BAO) comprise 10-20% of all large vessel occlusion cases but carry high mortality and morbidity rates, reaching up to 95% if recanalization is not achieved. The optimal approach for treatment of this life-threatening condition – including the optimal time-window – is still heavily debated. Mechanical thrombectomy is currently the standard of care for this population in most stroke centers, despite the lack of evidence compared to anterior circulation.

Studies up until now showed that some factors are related to better recanalization rates in this population and hence, better prognosis. These variables were hyperdense basilar artery, short thrombus length, early initiation of endovascular therapy and contact aspiration. Some case-reports have also suggested that anatomic and hemodynamic factors related to reversal flow and patency of vertebral arteries could affect recanalization success.

The primary objective of this study by Boeckh-Behrens et al. was to to investigate the association between low flow condition contralateral to the catheter-bearing vertebral artery and  successful recanalization post-mechanical thrombectomy (MT) in a population individuals with acute basilar artery occlusion. The authors hypothesized that patients with low flow condition defined as either aplastic or hypoplastic vertebral artery (< 50% of the dominant artery) contralateral to the catheter position have more chances to achieve complete recanalization once they have less risk of distal emboli.

All patients were subjected to digital subtraction angiography. The complete vertebrobasilar axis recanalization was defined as grade 9 (on a scale of 1 to 9), and it could be achieved with or without residual branch occlusion.

Elena Zapata-Arriaza, MD
@ElenaZaps

Compagne KCJ, van der Sluijs PM, van den Wijngaard IR, Roozenbeek B, Mulder MJHL, van Zwam WH, et al. Endovascular Treatment: The Role of Dominant Caliber M2 Segment Occlusion in Ischemic Stroke. Stroke. 2019;50:419–427.

Despite the recently demonstrated benefit of endovascular treatment (EVT) for proximal large vessel occlusion (LVO) of the anterior circulation (ICA and M1), evidence for treatment benefit of more distal occlusions, including the M2 segment of the middle cerebral artery (MCA), is limited, and further studies are necessary to address this question. In addition, the efficacy and safety of EVT in M2 occlusions remain unproven.

To determine the efficacy and safety of EVT in M2 occlusions, the authors performed an observational study with data obtained from the MR CLEAN registry. Only patients with a documented M1 or M2 target occlusion on baseline digital subtraction angiography (DSA) were included.

Caliber dominance was considered present if 1 M2 branch had a larger diameter than the other on DSA or if the perfusion defect associated with the occluded M2 branch was larger than 50% of MCA territory. Only when the diameters of both the inferior and superior branches were equal and the associated perfusion defect was ≈50% of MCA territory, the branches were considered codominant. DSA-only procedures were cases in which the target occlusion resolved or migrated too distally (M3 or M4 branches) caused by contrast flushing or manipulation with the catheter, without actual performing of intended EVT.