Cranial neurosurgery procedure utilization among patients with acute ischemic stroke.

BACKGROUND: Concerns about ready access to neurosurgery after acute ischemic stroke (AIS) may delay or prevent intravenous thrombolysis, thereby leading to poor outcomes. A randomized trial exploring the need for back-up neurosurgery in AIS is unlikely. However, insight may be gained from routine clinical practice. We analyzed the odds and temporal trends of cranial neurosurgery procedure use in patients with AIS using a large U.S. administrative database. METHODS: Data from AIS patients in the Nationwide Inpatient Sample (October 1998 to 2006) who underwent a cranial neurosurgical procedure were analyzed. Multivariate logistic regression with covariate adjustment was used for statistical analysis. Results were stratified by thrombolysis status. Intracerebral hemorrhage (ICH) was used as a key covariate. RESULTS: Intravenous thrombolysis use increased significantly over time (0.8% to 2.5%; P<.001). Cranial neurosurgical procedures were observed infrequently but increased significantly over time (0.12% to 0.19%; P=.0013), and thrombolysis doubled the odds of a procedure (odds ratio 2.18; 95% confidence interval 1.48-3.21; P<.001). However, thrombolysis only significantly increased the odds of a neurosurgical procedure in the absence of ICH (P<.001). CONCLUSIONS: Thrombolysis should probably not be withheld from eligible AIS patients, even if a concern exists about the lack of readily available neurosurgery, because neurosurgical procedure use is low in routine clinical practice, even after intravenous thrombolysis. Future studies and prospective data might help define the need for standby neurosurgery after AIS and provide further focus on the specific linkage to ICH as a possible mediator variable.

Weighting components of composite end points in clinical trials: an approach using disability-adjusted life-years.

BACKGROUND AND PURPOSE: Conventional analysis of vascular prevention trials assigns equal weight to disparate vascular events in a composite end point at variance with the public's perception of their differential impact on health outcome. This study sought to apply the disability-adjusted life-year (DALY) metric to differential weighting individual vascular end points in trial analyses. METHODS: DALY values for the most common major end points in vascular prevention trials (nonfatal myocardial infarction, nonfatal stroke, and vascular death), were derived by using World Health Organization Global Burden of Disease Project methodology. The standardized DALYs for each event were applied to recent major primary and secondary vascular prevention trials and to hypothetical model trials. RESULTS: Standardized DALYs lost were 7.63 for nonfatal stroke, 5.14 for nonfatal myocardial infarction, and 11.59 for vascular death. In the published trials analyses, the direction of treatment effects was consistent between DALY and standard event analysis, but the rank order of treatment effect changed for 10 of 18 trials. The DALY analysis also permitted derivation of number-needed-to-treat values to gain 1 DALY: 2.1 for anticoagulation in atrial fibrillation, 2.7 for carotid endarterectomy in symptomatic stenosis, and 4.7 for clopidogrel added to aspirin in acute coronary syndrome. Hypothetical trial analyses demonstrated that the DALY metric more finely discriminates treatment effects. CONCLUSIONS: Compared with a nonfatal myocardial infarction, a nonfatal stroke causes a 1.48-fold greater loss and vascular death a 2.25-fold greater loss of DALY. DALY analysis integrates these valuations in a summary metric reflecting the net impact of therapy on patient and societal health, complementing conventional end point analyses.

Analysis of thrombi retrieved from cerebral arteries of patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Information regarding the histological structure of thromboemboli that cause acute stroke provides insight into pathogenesis and clinical management. METHODS: This report describes the histological analysis of thromboemboli retrieved by endovascular mechanical extraction from the middle cerebral artery (MCA) and intracranial carotid artery (ICA) of 25 patients with acute ischemic stroke. RESULTS: The large majority (75%) of thromboemboli shared architectural features of random fibrin:platelet deposits interspersed with linear collections of nucleated cells (monocytes and neutrophils) and confined erythrocyte-rich regions. This histology was prevalent with both cardioembolic and atherosclerotic sources of embolism. "Red" clots composed uniquely of erythrocytes were uncommon and observed only with incomplete extractions, and cholesterol crystals were notably absent. The histology of thromboemboli that could not be retrieved from 29 concurrent patients may be different. No thrombus >3 mm wide caused stroke limited to the MCA, and no thrombus >5 mm wide was removed from the ICA. A mycotic embolus was successfully removed in 1 case, and a small atheroma and attached intima were removed without clinical consequence from another. CONCLUSIONS: Thromboemboli retrieved from the MCA or intracranial ICA of patients with acute ischemic stroke have similar histological components, whether derived from cardiac or arterial sources. Embolus size determines ultimate destination, those >5 mm wide likely bypassing the cerebral vessels entirely. The fibrin:platelet pattern that dominates thromboembolic structure provides a foundation for both antiplatelet and anticoagulant treatment strategies in stroke prevention.

Hyperacute imaging of ischemic stroke: role in therapeutic management.

Ischemic stroke remains a significant cause of morbidity and mortality. Current therapeutic options for acute ischemic stroke include intravenous thrombolysis and endovascular approaches for recanalization of proximal arterial occlusion. The rapid identification of underlying stroke etiology or mechanism may facilitate selection criteria for emergent therapy. Hyperacute imaging plays an integral role in the delineation of stroke pathophysiology and the formulation of rational stroke therapy. Hyperacute imaging of ischemic stroke may demonstrate proximal vascular occlusion, compensatory collateral circulation, residual or collateral tissue perfusion, and the differentiation of ischemic core from penumbral regions. Characterization of the ischemic field, including core and penumbra, with various mismatch models on multimodal computed tomography or MRI may refine current therapeutic strategies for cerebral ischemia. The diagnostic and therapeutic role of hyperacute imaging has emerged as a pivotal component in the evaluation and management of ischemic stroke.

In-hospital initiation of secondary stroke prevention therapies yields high rates of adherence at follow-up.

BACKGROUND AND PURPOSE: The Stroke PROTECT (Preventing Recurrence Of Thromboembolic Events through Coordinated Treatment) program systematically implements, at the time of acute transient ischemic attack (TIA) or ischemic stroke admission, 8 medication/behavioral secondary prevention measures known to improve outcome in patients with cerebrovascular disease. The objective of this study was to determine if the high utilization rates previously demonstrated at hospital discharge were maintained at 90 days after discharge. METHODS: Data were prospectively collected on consecutively encountered ischemic stroke and TIA patients admitted to a university hospital stroke service beginning September 1, 2002. PROTECT interventions were initiated before hospital discharge in all PROTECT-target (underlying stroke mechanism large vessel atherosclerosis or small vessel disease) and PROTECT-ACS (At-risk for Coronary Sequelae) patients. Adherence to program goals was assessed 3 months after discharge. RESULTS: During the period from September 2002 to August 2003, 144 individuals met criteria for PROTECT intervention. Of the 130 patients (90%) with available day 90 follow-up data, mean age was 72 (range, 37 to 95), and 63% were male. Adherence rates in patients without specific contraindications were 100% for antithrombotics, 99% for statins, 92% for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and 80% for thiazides. Awareness of the importance of calling 911 in response to stroke was 87%. Adherence to diet and exercise guidelines were 78% and 70%, respectively. Of the 24 smokers, tobacco cessation was maintained in 20 (83%). CONCLUSIONS: High rates of adherence to PROTECT therapies were maintained at 90 days after hospital discharge.

The acute cerebrovascular event: surgical and other interventional therapies.

Over the next decade, more early and aggressive treatments will become available for acute stroke. As EPs have been forced to push their skills and knowledge significantly further with the advent of time-sensitive interventions for myocardial ischemia, a similar sophistication will undoubtedly emerge in the management of acute stroke. Certain components of the neurological examination will likely assume a new significance and, as with the renewed focus on the nature of ST segment change on the ECG in ACS, there will be new attention to early imaging findings in stroke. Although it is unclear whether the balance of future advances in treatment will come from the world of neurosurgery, neurology, or interventional radiology, the EP is relatively assured to play a central role in their implementation.