Tuesday, May 24, 2016

Clinical Implications and Determinants of Left Atrial Mechanical Dysfunction in Patients with Stroke

Peggy Nguyen, MD

Kim D, Shim CY, Hong G-R, Kim M-H, Seo J, Cho IJ, et al. Clinical Implications and Determinants of Left Atrial Mechanical Dysfunction in Patients With Stroke. Stroke. 2016

Cardiovascular evaluation is an important part of the evaluation of the stroke patient, in part due to its use to diagnose cardioembolic etiologies of stroke, but also to assess for risk of future events. Left atrial enlargement has been associated with recurrent and first episodes of stroke, even in cases where dysrhythmias are not present; however, the mechanism by which this occurs is not well understood. Here, the authors use TTE with speckle tracking imaging to (1) assess enlargement and impaired mechanical function of the left atrium to define the risk of cardioembolism in stroke patients and (2) define the major determinants of left atrial mechanical dysfunction in these patients.

Monday, May 23, 2016

Validating Functional Outcome Prediction Models in Acute Ischemic Stroke: Testing the ASTRAL and DRAGON Scores

Danny R. Rose, Jr., MD

Cooray C, Mazya M, Bottai M, Dorado L, Skoda O, Toni D, et al. External Validation of the ASTRAL and DRAGON Scores for Prediction of Functional Outcome in Stroke. Stroke. 2016

Given that functional outcome is one of the most commonly used parameters in studying acute stroke treatment, developing accurate prognostication scores would greatly facilitate treatment decisions and improve communicating expectations to patients and families. Cooray et al. sought to validate the two most recently developed scores designed to predict functional outcome at three months, one studied in unselected acute stroke patients (ASTRAL) and the other in acute stroke patients treated with iv-tPA (DRAGON) using the SITS-International Stroke Thrombolysis Register (ISTR), a  global stroke thrombolysis database. Outcomes were dichotomized into modified Rankin Scale (mRS) 0-2 and 3-6 as were done in both of the initial studies, and the area under the curve (AUC) of the receiver operating characteristic (ROC) was used in both scores to assess the overall predictive and discriminative performance.

Friday, May 20, 2016

Predicting Large Vessel Occlusions in Ischemic Stroke Patients: Search for the Holy Scale

Ilana Spokoyny, MD

If a scale existed that could accurately predict the presence of large vessel occlusion (LVO), it would be extremely useful in triaging patients to either primary or comprehensive stroke centers (CSCs). For patients with LVO who are candidates for endovascular therapy, every minute is critical. Time lost by triaging these patients to primary stroke centers (PSCs) without endovascular capability is time and brain lost. Unfortunately, the range of stroke scales is wide and score cutoffs are inconsistent, and data on their predictive value for detecting LVO is limited. 

Thursday, May 19, 2016

Structured Nurse Practitioner Transitional Stroke Program Reduced 30-day Readmissions after Stroke

Qing Hao, MD, PhD

Condon C, Lycan S, Duncan P, and Bushnell C. Reducing Readmissions After Stroke With a Structured Nurse Practitioner/Registered Nurse Transitional Stroke Program. Stroke. 2016

After discharge from hospital, strokes survivors usually are faced with physical and cognitive impairments, complex medication regimen, new diagnosis of other medical illness and need of social support which all significantly affect stroke recovery and readmissions due to stroke related complications or other medical conditions. The experience from non-stroke patients that addressed the cumulative complexity (patients’ demands and capacity) have demonstrated effective interventions for reducing 30-day readmissions, however, the transitional care models for stroke patients have not been well established. Condon and colleagues developed a model of Transitional Stroke Clinic (TSC) led by nurse practitioner(NP) and investigated its role in reducing readmissions by conducting an observational quality improvement study in a single academic, tertiary referral center.

Wednesday, May 18, 2016

Inverse Relationship Between Leukocyte Count and ICH Hematoma Expansion

Alexander E. Merkler, MD 

Intracerebral hemorrhage (ICH) is a catastrophic type of stroke with a one-month mortality of 40%. Although initial ICH volume is the strongest predictor of mortality, hematoma expansion is a potentially modifiable risk factor that correlates well with both functional outcome and death and occurs in up to 40% of patients with ICH. Research has therefore focused on 1) identification of factors that predict hematoma expansion and 2) methods to reduce hematoma expansion. 

Tuesday, May 10, 2016

Declining Rate of IV Heparin Use in Acute Ischemic Stroke in Korea

Jay Shah, MD

Chung J-W, Kim BJ, Han M-K, Ko Y, Lee S, Kang K, et al. Impact of Guidelines on Clinical Practice: Intravenous Heparin Use for Acute Ischemic Stroke. Stroke. 2016

IV heparin has been available since the 1940’s and its role in ischemic stroke has been constantly debated. IV heparin has a clear indication in cardiac ischemia and many presume its efficacy should translate in acute ischemic stroke as well. However, numerous studies have failed to show benefit and American Stroke Association does not recommend anticoagulation acutely. Because heparin has been available for numerous years, there is little information on contemporary use and this study evaluated recent IV heparin trends across 12 hospitals in Korea in a 5 year span from 2008-2013.

Monday, May 9, 2016

Limited Meta-analysis Suggests Patients with Asymptomatic Carotid Occlusion are at Low Risk of Ipsilateral Stroke, High Risk of Non-stroke Mortality

Danny R. Rose, Jr., MD

Hackam DG. Prognosis of Asymptomatic Carotid Artery Occlusion: Systematic Review and Meta-Analysis. Stroke. 2016

Although carotid artery occlusion is estimated to account for 10-15% of all ischemic strokes and transient ischemic attacks, there is little consensus regarding the long-term prognosis of asymptomatic carotid artery occlusion (ACAO), which is most often found incidentally during workup for cerebrovascular disease. Hackam sought to shed light on this issue by conducting a systematic review of studies that enrolled patients with ACAO that collected follow-up information on the occurrence of ipsilateral ischemic stroke as an outcome measure. 

Friday, May 6, 2016

Heart Rate Variability and Incident Stroke Risk in the Atherosclerosis Risk in Communities Study

Neal S. Parikh, MD

In this issue of Stroke, Amber Fyfe-Johnson and colleagues describe their investigation of the association between heart rate variability (HRV) and incident stroke risk in the Atherosclerosis Risk in Communities (ARIC) Study cohort.

They argue that autonomic nervous system (ANS) dysfunction, as reflected by HRV, may be associated with cardiovascular mortality, coronary heart disease, and mortality in stroke survivors. ANS dysfunction may be associated with dysregulated cerebrovascular autoregulation and blood pressure.