Stroke Literature Synopses: Clinical Science
Prabhakaran S, O’Neill K, Stein-Spencer L, Walter J, Alberts MJ. Prehospital triage to primary stroke centers and rate of stroke thrombolysis. JAMA Neurol. 2013;70:1126–1132.
Using the Get With The Guidelines database, Prabhakaran et al retrospectively assessed rates of intravenous thrombolysis at 10 Chicago primary stroke centers (PSCs) in the 6 months before and 6 months after the institution of a citywide policy recommending prehospital triage of patients with suspected stroke to the nearest PSC. Before prehospital triage, 1075 patients with stroke and transient ischemic attack were admitted to the 10 PSCs; post-triage, 1172 were admitted. The proportion of stroke/transient ischemic attack admissions presenting by ambulance increased from 30.2% pretriage to 38.1% post-triage, hospital prenotification increased from 65.5% to 76.5%, rates of intravenous tissue plasminogen activator (tPA) delivery increased from 3.8% to 10.1%, and onset-to-treatment times decreased from 171.7 to 145.7 minutes (all P<0.05). Stroke unit admission, symptomatic intracranial hemorrhage rates, and in-hospital mortality were not significantly different between periods. Adjusting for mode of arrival, prehospital notification, and onset-to-arrival time, the post-triage period was independently associated with increased tPA use for patients with ischemic stroke (adjusted odds ratio [OR], 2.21; 95% confidence interval, 1.34–3.64). These findings are consistent with the experience of other metropolitan areas—such as Phoenix, Toronto, New York, Houston, and London—that implemented prehospital triage of patients with stroke to specialized centers. The findings demonstrate the effectiveness of prehospital triage in augmenting use of tPA at PSCs and reinforce the need to develop organized city-/county-wide systems of stroke care. Although we can postulate that a higher proportion of tPA-eligible individuals were routed to PSCs in Chicago as a result of the policy change, a notable limitation of the study is the lack of data regarding individuals admitted to non-PSC hospitals. Future studies on the impact of regional policies should attempt to assess the impact of such policies on the entire region/population affected.
Tu HT, Campbell BC, Meretoja A, Churilov L, Lees KR, Donnan GA, et al. Pre-stroke CHADS2 and CHA2DS2-VASc scores are useful in stratifying three-month outcomes in patients with and without atrial fibrillation. Cerebrovasc Dis. 2013;36:273–280.
Tu et al performed a retrospective analysis of the Virtual International Stroke Trials Archive (VISTA) database to determine whether prestroke CHADS2 and CHA2DS2-VASc scores were associated with 3-month outcomes in patients with and without atrial fibrillation (AF). Of the 28 190 patients with acute ischemic stroke in the database, 6612 had data on age, sex, tPA treatment, prestroke history of congestive heart failure, hypertension, diabetes mellitus, stroke, transient ischemic attack, myocardial infarction, AF, baseline National Institutes of Health Stroke Scale, 3-month modified Rankin scale, 3-month mortality, and cardiac complications. After multivariable logistic regression, high-risk (≥2) prestroke CHADS2 and CHA2DS2-VASc scores were associated with greater 3-month mortality (CHADS2 OR, 2.33; 95% confidence interval, 1.81–3.00; CHA2DS2-VASc OR, 3.01; 2.00–4.80) and serious cardiac adverse events (CHADS2 OR, 1.76; 1.28–2.42; CHA2DS2-VASc OR, 2.69; 1.53–4.73) and lower odds of good functional outcomes (CHADS2 OR, 0.47; 0.39–0.57; CHA2DS2-VASc OR, 0.55; 0.42–0.71) compared with low-risk scores. The prestroke CHA2DS2-VASc score was better than CHADS2 in estimating 3-month stroke outcomes (P≤0.005 in all area under the receiver operator characteristic curves comparisons). High-risk prestroke CHA2DS2-VASc score had high sensitivity for mortality (AF: 0.96; 0.94–0.98; no AF: 0.88; 0.86–0.91) and negative predictive value for serious cardiac events (AF: 0.93; 0.87–0.96; no AF: 0.96; 0.95–0.97). Low-risk prestroke CHA2DS2-VASc score had high specificity for good functional outcome (AF: 0.99; 0.98–0.99; no AF: 0.94; 0.93–0.95) at 3 months.
Given these findings, the prestroke CHA2DS2-VASc score may be a simple useful tool for identifying individuals at low risk for poor outcomes within the first 3 months after stroke. The study’s strengths include the large international sample and use of 2 familiar simple tools. However, the patients in this database are individuals enrolled in clinical trials; therefore, they are not representative of the overall stroke population. In addition, given their modest precision in estimating 3-month mortality and functional outcome following stroke, neither CHADS2 nor CHA2DS2-VASc score is suitable for those purposes. In the interest of identifying a known, familiar prognostic tool, the authors did not include one of the most important stroke prognosticators: stroke severity.
CHA2DS2-VASc score, however, may have an important clinical role in identifying individuals at high risk for cardiac events who warrant additional diagnostic evaluation for coronary heart disease and may require interventions for preventing coronary heart disease. A retrospective analysis of a randomized controlled trial has previously shown that baseline high Framingham Coronary Heart Disease Risk Score (FCRS) was associated with a higher risk of myocardial infarction and vascular death after stroke.1 Prospective studies may be warranted to compare the usefulness of CHA2DS2-VASc versus FCRS in identifying stroke survivors at high risk for cardiac disease who might benefit from evaluation for and management of coronary heart disease.
- © 2013 American Heart Association, Inc.