Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: a multicenter study

OBJECTIVES

Stroke risk immediately after TIA defined by time-based criteria is high, and prognostic scores (ABCD2 and ABCD3-I) have been developed to assist management. The American Stroke Association has proposed changing the criteria for the distinction between TIA and stroke from time-based to tissue-based. Research using these definitions is lacking. In a multicenter observational cohort study, we have investigated prognosis and performance of the ABCD2 score in TIA, subcategorized as tissue-positive or tissue-negative on diffusion-weighted imaging (DWI) or CT imaging according to the newly proposed criteria.

METHODS

Twelve centers provided data on ABCD2 scores, DWI or CT brain imaging, and follow-up in cohorts of patients with TIA diagnosed by time-based criteria. Stroke rates at 7 and 90 days were studied in relation to tissue-positive or tissue-negative subcategorization, according to the presence or absence of brain infarction. The predictive power of the ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses.

RESULTS

A total of 4,574 patients were included. Among DWI patients (n = 3,206), recurrent stroke rates at 7 days were 7.1%(95% confidence interval 5.5-9.1) after tissue-positive and 0.4% (0.2-0.7) after tissue-negative events (p diff < 0.0001). Corresponding rates in CT-imaged patients were 12.8% (9.3-17.4) and 3.0% (2.0-4.2), respectively (p diff < 0.0001). The ABCD2 score had predictive value in tissue-positive and tissue-negative events (AUC = 0.68 [95% confidence interval 0.63-0.73] and 0.73 [0.67-0.80], respectively; p sig < 0.0001 for both results, p diff = 0.17). Tissue-positive events with low ABCD2 scores and tissue-negative events with high ABCD2 scores had similar stroke risks, especially after a 90-day follow-up.

CONCLUSIONS

Our findings support the concept of a tissue-based definition of TIA and stroke, at least on prognostic grounds.

Who will participate in acute stroke trials?

BACKGROUND

Despite the high incidence of acute stroke, only a minority of patients are enrolled in acute stroke treatment trials. We aimed to identify factors associated with participation in clinical trials of novel therapeutic agents for acute stroke.

METHODS

Prospective survey of patients with acute stroke <72 hours from onset. A structured interview was administered to the patient or primary decision-maker. If offered participation in an actual acute treatment trial, questions focused on decisions about that trial; otherwise a similar mock trial was proposed. The primary outcome was whether the subject agreed to participate in the proposed trial.

RESULTS

A total of 200 subjects (47% patients, 53% proxies) completed the survey: mean age 63 +/- 14 years, 47% women, 44% white, 50% black. A real acute trial was offered to 22%; others were offered a mock trial. Overall, 57% (95% confidence interval: 50%-64%) of respondents stated they would participate in the proposed acute treatment trial. There were no differences with respect to age, sex, race, educational level, self-assessed stroke severity or stroke type, vascular risk factors, or comorbidities. Misconceptions about key research concepts were found in 50% but did not impact participation. Participation was associated with the perceived risk of the proposed trial intervention (p < 0.001), prior general attitudes about research (p < 0.001), and influences attributed to family, religion, and other personal beliefs (p < 0.001). Patients were more likely to participate than proxy decision-makers (p = 0.04).

CONCLUSIONS

Demographic factors, clinical factors, and prior knowledge about research have little impact on the decision to participate in acute stroke clinical trials. Preexisting negative attitudes and external influences about research strongly inhibit participation. Patients are more inclined to participate than their proxy decision-makers.

Prior antiplatelet use does not affect hemorrhage growth or outcome after ICH

OBJECTIVE

To examine whether antiplatelet medication use at onset of intracerebral hemorrhage (ICH) is associated with hemorrhage growth and outcome after spontaneous ICH using a large, prospectively collected database from a recent clinical trial.

METHODS

The Cerebral Hemorrhage and NXY-059 Treatment trial was a randomized, placebo-controlled trial of NXY-059 after spontaneous ICH. We analyzed patients in the placebo arm, and correlated antiplatelet medication use at the time of ICH with initial ICH volumes, ICH growth in the first 72 hours, and modified Rankin Score at 90 days. Patients on oral anticoagulation were excluded.

RESULTS

There were 282 patients included in this analysis, including 70 (24.8%) who were taking antiplatelet medications at ICH onset. Use of antiplatelet medications at ICH onset had no association with the volume of ICH at presentation, growth of ICH at 72 hours, initial edema volume, or edema growth. In multivariable analysis, there was no association of use of antiplatelet medications with any hemorrhage expansion (relative risk [RR] 0.85 [upper limit of confidence interval (UCI) 1.03], p = 0.16), hemorrhage expansion greater than 33% (RR 0.77 [UCI 1.18], p = 0.32), or clinical outcome at 90 days (odds ratio 0.67, 95% confidence interval 0.39-1.14, p = 0.14).

CONCLUSIONS

Use of antiplatelet medications at intracerebral hemorrhage (ICH) onset is not associated with increased hemorrhage volumes, hemorrhage expansion, or clinical outcome at 90 days. These findings suggest that attempts to reverse antiplatelet medications after ICH may not be warranted.

Safety of intra-arterial thrombolysis in the postoperative period

BACKGROUND AND PURPOSE

Limited systemic fibrinolysis and reduced dosage are features of intra-arterial thrombolyis (IAT) that may be advantageous in the treatment of postoperative strokes. However, IAT may increase the risk of surgical bleeding. We sought to determine the safety of postoperative IAT.

METHODS

This was a retrospective case series from 6 university hospitals. All cases of IAT within 2 weeks of surgery were identified. Demographics, stroke mechanism, stroke severity, imaging and angiographic findings, time between surgery and lysis, thrombolytic agent used, surgical site bleeding, intracranial bleeding, and mortality rates were determined. Death or complications directly related to IAT were determined.

RESULTS

Thirty-six patients (median age, 71.5 years; range, 45 to 85) were identified. Median time from surgery to stroke was 21.5 hours (range, 1 to 120). Open heart surgery was done in 18 (50%), carotid endarterectomy in 6 (17%), craniotomy in 3 (8%), ophthalmologic-ear, nose and throat surgery in 2 (6%), urologic-gynecologic surgery in 4 (11%), orthopedic surgery in 2 (6%), and plastic surgery in 1 (3%). The stroke causes were cardioembolism in 24 (67%), large-vessel atherosclerosis in 4 (11%), dissection in 3 (8%), postendarterectomy occlusion in 4 (11%), and radiation arteriopathy in 1 (3%). Median time to angiogram was 2.5 hours (0.1 to 5.5). Occlusion sites were M1 in 19 (53%), M2 in 9 (25%), internal carotid artery in 5 (14%), basilar artery in 2 (6%), and posterior communicating artery in 1 (3%). Thrombolysis was completed at a median of 4.5 hours (range, 1 to 8.0). Tissue plasminogen activator was used in 19 (53%) and urokinase in 17 (47%). Nine (26%) patients died. Surgical site bleeding occurred in 9 (25%) cases (minor in 6, major in 3). The major surgical bleeds were 2 post-craniotomy intracranial hemorrhages and 1 hemopericardium after coronary artery bypass grafting; all were fatal. Six deaths were non-IAT related: 3 caused by cerebral edema and 3 by systemic causes. Major bleeding complications were significantly more common among patients with craniotomy (P<0.02).

CONCLUSIONS

Postoperative IAT carries a risk of bleeding in up to 25% of patients but is usually minor surgical site bleeding. Avoiding IAT in intracranial surgery patients may reduce complications. Mortality rate in this series was similar to that reported in prior IAT trials. IAT remains a viable therapeutic option for postoperative strokes.

Reliability and validity of estimating the NIH stroke scale score from medical records

BACKGROUND AND PURPOSE

The aim of our study was to determine whether the National Institutes of Health Stroke Scale (NIHSS) can be estimated retrospectively from medical records. The NIHSS is a quantitative measure of stroke-related neurological deficit with established reliability and validity for use in prospective clinical research. Recently, retrospective observational studies have estimated NIHSS scores from medical records for quantitative outcome analysis. The reliability and validity of estimation based on chart review has not been determined.

METHODS

Thirty-nine patients were selected because their NIHSS scores were formally measured at admission and discharge. Handwritten notes from medical records were abstracted and NIHSS scores were estimated by 6 raters who were blinded to the actual scores. Estimated scores were compared among raters and with the actual measured scores.

RESULTS

Interrater reliability was excellent, with an intraclass correlation coefficient of 0.82. Scores were well calibrated among the 6 raters. Estimated NIHSS scores closely approximated the actual scores, with a probability of 0.86 of correctly ranking a set of patients according to 5-point interval categories (as determined by the area under the receiver-operator characteristic curve). Patients with excellent outcomes (NIHSS score of </=5) could be identified with sensitivity of 0.72 and specificity of 0.89. There were no significant differences between these parameters at admission and discharge.

CONCLUSIONS

For the purposes of retrospective studies of acute stroke outcome, the NIHSS can be abstracted from medical records with a high degree of reliability and validity.