A tool to identify patients with embolic stroke of undetermined source at high recurrence risk

OBJECTIVE

A tool to stratify the risk of stroke recurrence in patients with embolic stroke of undetermined source (ESUS) could be useful in research and clinical practice. We aimed to determine whether a score can be developed and externally validated for the identification of patients with ESUS at high risk for stroke recurrence.

METHODS

We pooled the data of all consecutive patients with ESUS from 11 prospective stroke registries. We performed multivariable Cox regression analysis to identify predictors of stroke recurrence. Based on the coefficient of each covariate of the fitted multivariable model, we generated an integer-based point scoring system. We validated the score externally assessing its discrimination and calibration.

RESULTS

In 3 registries (884 patients) that were used as the derivation cohort, age, leukoaraiosis, and multiterritorial infarct were identified as independent predictors of stroke recurrence and were included in the final score, which assigns 1 point per every decade after 35 years of age, 2 points for leukoaraiosis, and 3 points for multiterritorial infarcts (acute or old nonlacunar). The rate of stroke recurrence was 2.1 per 100 patient-years (95% confidence interval [CI] 1.44-3.06) in patients with a score of 0-4 (low risk), 3.74 (95% CI 2.77-5.04) in patients with a score of 5-6 (intermediate risk), and 8.23 (95% CI 5.99-11.3) in patients with a score of 7-12 (high risk). Compared to low-risk patients, the risk of stroke recurrence was significantly higher in intermediate-risk (hazard ratio [HR] 1.78, 95% CI 1.1-2.88) and high-risk patients (HR 4.67, 95% CI 2.83-7.7). The score was well-calibrated in both derivation and external validation cohorts (8 registries, 820 patients) (Hosmer-Lemeshow test χ²: 12.1 [p = 0.357] and χ²: 21.7 [p = 0.753], respectively). The area under the curve of the score was 0.63 (95% CI 0.58-0.68) and 0.60 (95% CI 0.54-0.66), respectively.

CONCLUSIONS

The proposed score can assist in the identification of patients with ESUS at high risk for stroke recurrence.

Renal Function and Risk Stratification of Patients With Embolic Stroke of Undetermined Source

Background and Purpose- We aimed to assess if renal function can aid in risk stratification for ischemic stroke or transient ischemic attack (TIA) recurrence and death in patients with embolic stroke of undetermined source (ESUS). Methods- We pooled 12 ESUS datasets from Europe and America. Renal function was evaluated using the estimated glomerular filtration rate (eGFR) and analyzed in continuous, binary, and categorical way. Cox-regression analyses assessed if renal function was independently associated with the risk for ischemic stroke/TIA recurrence and death. The Kaplan-Meier product limit method estimated the cumulative probability of ischemic stroke/TIA recurrence and death. Results- In 1530 patients with ESUS followed for 3260 patient-years, there were 237 recurrences (15.9%) and 201 deaths (13.4%), corresponding to 7.3 ischemic stroke/TIA recurrences and 5.6 deaths per 100 patient-years, respectively. Renal function was not associated with the risk for ischemic stroke/TIA recurrence when forced into the final multivariate model, regardless if it was analyzed as continuous (hazard ratio, 1.00; 95% CI, 0.99-1.00 for every 1 mL/min), binary (hazard ratio, 1.27; 95% CI, 0.87-1.73) or categorical covariate (likelihood-ratio test 2.59, P=0.63 for stroke recurrence). The probability of ischemic stroke/TIA recurrence across stages of renal function was 11.9% for eGFR ≥90, 16.6% for eGFR 60-89, 21.7% for eGFR 45-59, 19.2% for eGFR 30-44, and 24.9% for eGFR <30 (likelihood-ratio test 2.59, P=0.63). The results were similar for the outcome of death. Conclusions- The present study is the largest pooled individual patient-level ESUS dataset, and does not provide evidence that renal function can be used to stratify the risk of ischemic stroke/TIA recurrence or death in patients with ESUS.

Age- and sex-specific analysis of patients with embolic stroke of undetermined source

OBJECTIVE

To investigate whether the correlation of age and sex with the risk of recurrence and death seen in patients with previous ischemic stroke is also evident in patients with embolic stroke of undetermined source (ESUS).

METHODS

We pooled datasets of 11 stroke registries from Europe and America. ESUS was defined according to the Cryptogenic Stroke/ESUS International Working Group. We performed Cox regression and Kaplan-Meier product limit analyses to investigate whether age (<60, 60-80, >80 years) and sex were independently associated with the risk for ischemic stroke/TIA recurrence or death.

RESULTS

Ischemic stroke/TIA recurrences and deaths per 100 patient-years were 2.46 and 1.01 in patients <60 years old, 5.76 and 5.23 in patients 60 to 80 years old, 7.88 and 11.58 in those >80 years old, 3.53 and 3.48 in women, and 4.49 and 3.98 in men, respectively. Female sex was not associated with increased risk for recurrent ischemic stroke/TIA (hazard ratio [HR] 1.15, 95% confidence interval [CI] 0.84-1.58) or death (HR 1.35, 95% CI 0.97-1.86). Compared with the group <60 years old, the 60- to 80- and >80-year groups had higher 10-year cumulative probability of recurrent ischemic stroke/TIA (14.0%, 47.9%, and 37.0%, respectively, p < 0.001) and death (6.4%, 40.6%, and 100%, respectively, p < 0.001) and higher risk for recurrent ischemic stroke/TIA (HR 1.90, 95% CI 1.21-2.98 and HR 2.71, 95% CI 1.57-4.70, respectively) and death (HR 4.43, 95% CI 2.32-8.44 and HR 8.01, 95% CI 3.98-16.10, respectively).

CONCLUSIONS

Age, but not sex, is a strong predictor of stroke recurrence and death in ESUS. The risk is ≈3- and 8-fold higher in patients >80 years compared with those <60 years of age, respectively. The age distribution in the ongoing ESUS trials may potentially influence their power to detect a significant treatment association.

Efficacy of New Measures Saving Time in Acute Stroke Management: A Quantified Analysis

BACKGROUND

Time to treatment remains the most important factor in acute ischemic stroke prognosis. We quantified the effect of new interventions reducing in-hospital delays in acute stroke management and assessed its repercussion on door-to-imaging (DTI), imaging-to-needle (ITN), and door-to-needle (DTN) times.

METHODS

Prospective registry of consecutive stroke patients who were candidates for reperfusion therapy attended in a tertiary care hospital from February 1 to December 31, 2014. A series of measures aimed at reducing in-hospital delays were implemented. We compared DTI, ITN, and DTN times between patients who underwent the interventions and those who did not.

RESULTS

231 patients. DTI time was lower when personal history was reviewed and tests were ordered before patient arrival (2.5 minutes saved, P = .016) and when electrocardiogram was not made (5.4 minutes saved, P < .001). Not performing a computed tomography angiography and not waiting for coagulation results from laboratory before intravenous thrombolysis (25.5%) reduced ITN time significantly (14 and 12 minutes saved, respectively, P < .001). These interventions remained as independent predictors of a shorter ITN and DTN time. Completing all steps resulted in the lowest DTI and ITN times (13 and 19 minutes, respectively).

CONCLUSIONS

Every measure is an important part of a chain focused on saving time in acute stroke: the lowest DTI and ITN times were obtained when all steps were completed. Measures shortening ITN time produced a greater impact on DTN time reduction; therefore, ITN interventions should be considered a critical part of new protocols and guidelines.

Risk Stratification for Recurrence and Mortality in Embolic Stroke of Undetermined Source

Background and Purpose—

The risk of stroke recurrence in patients with Embolic Stroke of Undetermined Source (ESUS) is high, and the optimal antithrombotic strategy for secondary prevention is unclear. We investigated whether congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and stroke or transient ischemic attack (TIA; CHADS 2 ) and CHA 2 DS 2 -VASc scores can stratify the long-term risk of ischemic stroke/TIA recurrence and death in ESUS.

Methods—

We pooled data sets of 11 stroke registries from Europe and America. ESUS was defined according to the Cryptogenic Stroke/ESUS International Working Group. Cox regression analyses were performed to investigate if prestroke CHADS 2 and congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke or TIA, vascular disease, age 65–74 years, sex category (CHA 2 DS 2 -VASc) scores were independently associated with the risk of ischemic stroke/TIA recurrence or death. The Kaplan–Meier product limit method was used to estimate the cumulative probability of ischemic stroke/TIA recurrence and death in different strata of the CHADS 2 and CHA 2 DS 2 -VASc scores.

Results—

One hundred fifty-nine (5.6% per year) ischemic stroke/TIA recurrences and 148 (5.2% per year) deaths occurred in 1095 patients (median age, 68 years) followed-up for a median of 31 months. Compared with CHADS 2 score 0, patients with CHADS 2 score 1 and CHADS 2 score >1 had higher risk of ischemic stroke/TIA recurrence (hazard ratio [HR], 2.38; 95% confidence interval [CI], 1.41–4.00 and HR, 2.72; 95% CI, 1.68–4.40, respectively) and death (HR, 3.58; 95% CI, 1.80–7.12, and HR, 5.45; 95% CI, 2.86–10.40, respectively). Compared with low-risk CHA 2 DS 2 -VASc score, patients with high-risk CHA 2 DS 2 -VASc score had higher risk of ischemic stroke/TIA recurrence (HR, 3.35; 95% CI, 1.94–5.80) and death (HR, 13.0; 95% CI, 4.7–35.4).

Conclusions—

The risk of recurrent ischemic stroke/TIA and death in ESUS is reliably stratified by CHADS 2 and CHA 2 DS 2 -VASc scores. Compared with the low-risk group, patients in the high-risk CHA 2 DS 2 -VASc group have much higher risk of ischemic stroke recurrence/TIA and death, approximately 3-fold and 13-fold, respectively.