Incidence, predictors, and etiology of subsequent ischemic stroke within one year after transient ischemic attack

Distinguishing Transient Cerebral Ischemia From Other Brief Neurologic Events

"Nam et ipsa scientia potestas est ['knowledge itself is power']." Sir Francis Bacon, Meditationes Sacrae (1597).

Presenting Symptoms and Diffusion-Weighted MRI Positivity by Time After Transient Neurologic Events: A Pooled Analysis of 3 Cohort Studies

BACKGROUND AND OBJECTIVE

The association between focal vs nonfocal presenting symptom and diffusion-weighted imaging (DWI) positivity in relation to onset-to-imaging time in patients with transient neurologic events remains unclear. We hypothesize that episodes consisting of focal symptoms would have proportionally higher DWI-positive imaging at later onset-to-imaging times.

METHODS

Patients with transient neurologic symptoms and a normal neurologic examination who had DWI in the combined data set of 3 cohort studies were included. We used logistic regression models to evaluate the association between each type of presenting symptom (motor weakness, speech impairment, sensory symptoms, vision loss, diplopia, gait instability, dizziness, headache, presyncope, and amnesia) and DWI positivity after adjusting for clinical variables (age, sex, history of stroke, dyslipidemia, coronary artery disease, atrial fibrillation, symptoms duration [<10, 10-59, ≥60 minutes, or unclear], and study source). We stratified the results by onset-to-imaging time categories (<6 hours, 6-23 hours, and ≥24 hours).

RESULTS

Of the total 2,411 patients (1,345 male, median age 68 years), DWI-positive lesions were detected in 598 patients (24.8%). The prevalence of DWI positivity was highest in those with motor weakness (34.7%), followed by speech impairment (33.5%). In a multivariable analysis, the presence of motor weakness, speech impairment, and sensory symptoms was associated with DWI positivity, while vision loss and headache were associated with lower odds of DWI positivity, but nevertheless had 13.6% and 15.3% frequency of DWI positive. The odds of being DWI positive varied by onset-to-imaging time categories for motor weakness, with greater odds of being DWI positive at later imaging time (<6 hours: odds ratio [OR] 1.25, 95% confidence interval [CI] 0.84-1.87; 6-23 hours: OR 2.24, 95% CI 1.47-3.42; and ≥24 hours: OR 2.42, 95% CI 1.74-3.36; interaction p = 0.033). Associations of other symptoms with DWI positivity did not vary significantly by time categories.

DISCUSSION

We found that onset-to-imaging time influences the relationship between motor weakness and DWI positivity in patients with transient neurologic events. Compared with motor, speech, and sensory symptoms, visual or nonfocal symptoms carry a lower but still a substantive association with DWI positivity.

Multimodal MRI study of the relationship between plaque characteristics and hypoperfusion in patients with transient ischemic attack

Objective

Transient ischemic attack is a significant risk factor for acute cerebral infarction. Previous studies have demonstrated that hypoperfusion in patients with transient ischemic attack was associated with the recurrence of transient ischemic attack, stroke, and persistent worsening of neurological symptoms. Moreover, transient ischemic attack patients classified as high-risk group according to the ABCD2 score have a higher incidence of stroke. Therefore, the objective of this study was to investigate the plaque characteristics of transient ischemic attack patients with concomitant cerebral hypoperfusion using multimodal MRI, as well as hemodynamic changes in the high-risk group with transient ischemic attack patients.

Materials and methods

A total of 151 patients with transient ischemic attack were prospectively recruited for this study. All enrolled patients underwent multimodal MRI, including DWI, TOF-MRA, HR-VWI, and DSC-PWI. Finally, 56 patients met the inclusion criteria. Based on DSC-PWI images, patients were divided into two groups: hypoperfusion (n = 41) and non-hypoperfusion (n = 15). Clinical baseline characteristics and plaque characteristics were analyzed between the two groups. Furthermore, within the hypoperfusion group, patients were further classified into low-risk (n = 11) and high-risk (n = 30) subgroups based on the ABCD2 score. Hemodynamic differences between these subgroups were also analyzed.

Results

Compared with the non-hypoperfusion group, the hypoperfusion group had a significantly higher prevalence of hypertension (68.3% vs. 33.3%, p = 0.019) and hyperhomocysteinemia (65.9% vs. 33.3%, p = 0.029). Moreover, the hypoperfusion group exhibited more significant luminal stenosis degree [41.79 ± 31.36 vs. 17.62± 13.62, p = 0.006] and greater NWI (57.1%± 20.47% vs. 40.21%± 21.56%, p = 0.009) compared to the non-hypoperfusion group. In addition, the high-risk group identified by the ABCD2 score had a higher rMTT [117.6(109.31-128.14) vs. 108.36(100.67-119.92), p = 0.037].

Conclusion

Transient ischemic attack patients with hypoperfusion exhibited a higher prevalence of hypertension and hyperhomocysteinemia, as well as higher luminal stenosis degree, and greater NWI. Furthermore, Transient ischemic attack patients in the high-risk group demonstrated higher MTT.

Novel predictors and a predictive model of cerebrovascular atherosclerotic ischemic stroke based on clinical databases

BACKGROUND AND PURPOSE

Early identification of cerebrovascular atherosclerotic ischemic stroke is necessary for accurate treatment and clinical research.

AIMS

To identify novel predictors and build a predictive model of ischemic strokes due to cerebrovascular atherosclerosis.

METHOD

MIMIC-IV database was used to search for clinical data of patients with ischemic stroke. Included patients were divided into two groups according to their etiologies. Univariate and multivariate logistic regressions were used to build the predictive model, and the model reliability parameters were calculated. The cut-off value for the model was selected according to the Youden index. Clinical data from the Neurovascular Center of Changhai Hospital were used to verify the predictive model.

RESULTS

Logistical regressions showed a positive correlation between advanced age, peripheral atherosclerosis, history of transient ischemia, and the diagnosis of ischemic strokes due to cerebrovascular atherosclerosis. The history of atrial fibrillation, levels of the National Institutes of Health Stroke Scale, serum potassium, and activated partial thromboplastin time were negatively correlated to the diagnosis of cerebrovascular atherosclerotic ischemic stroke. The predictive model was constructed from logistic regression results, and the area under the curve was 0.764. The cut-off value for the model was set at 0.089 to achieve the highest Youden index, with sensitivity and specificity of 75.9% and 64.1%. Clinical verification of the model revealed that the sensitivity and specificity of the model were 52.5% and 93.0% respectively.

CONCLUSION

The efficacy of the predictive model was acceptable as an aid in predicting cerebrovascular atherosclerotic ischemic stroke.

One-Year Risk of Stroke After Transient Ischemic Attack or Minor Stroke in Hunter New England, Australia (INSIST Study)

Background: One-year risk of stroke in transient ischemic attack and minor stroke (TIAMS) managed in secondary care settings has been reported as 5-8%. However, evidence for the outcomes of TIAMS in community care settings is limited. Methods: The INternational comparison of Systems of care and patient outcomes In minor Stroke and TIA (INSIST) study was a prospective inception cohort community-based study of patients of 16 general practices in the Hunter-Manning region (New South Wales, Australia). Possible-TIAMS patients were recruited from 2012 to 2016 and followed-up for 12 months post-index event. Adjudication as TIAMS or TIAMS-mimics was by an expert panel. We established 7-days, 90-days, and 1-year risk of stroke, TIA, myocardial infarction (MI), coronary or carotid revascularization procedure and death; and medications use at 24 h post-index event. Results: Of 613 participants (mean age; 70 ± 12 years), 298 (49%) were adjudicated as TIAMS. TIAMS-group participants had ischemic strokes at 7-days, 90-days, and 1-year, at Kaplan-Meier (KM) rates of 1% (95% confidence interval; 0.3, 3.1), 2.1% (0.9, 4.6), and 3.2% (1.7, 6.1), respectively, compared to 0.3, 0.3, and 0.6% of TIAMS-mimic-group participants. At one year, TIAMS-group-participants had twenty-five TIA events (KM rate: 8.8%), two MI events (0.6%), four coronary revascularizations (1.5%), eleven carotid revascularizations (3.9%), and three deaths (1.1%), compared to 1.6, 0.6, 1.0, 0.3, and 0.6% of TIAMS-mimic-group participants. Of 167 TIAMS-group participants who commenced or received enhanced therapies, 95 (57%) were treated within 24 h post-index event. For TIAMS-group participants who commenced or received enhanced therapies, time from symptom onset to treatment was median 9.5 h [IQR 1.8-89.9]. Conclusion: One-year risk of stroke in TIAMS participants was lower than reported in previous studies. Early implementation of antiplatelet/anticoagulant therapies may have contributed to the low stroke recurrence.

Japanese and Non-Japanese Patients with Transient Ischemic Attack or Minor Stroke: A Five-Year Risk Analysis of Stroke and Vascular Events

AIMS

We have previously reported 5-year follow-up data on the TIAregistry.org, an international prospective cohort in patients with transient ischemic attack (TIA) or minor stroke. We conducted a Japanese subgroup analysis because outcomes and predictors might differ according to ethnicities and regions. In this study, we compared the baseline and 5-year follow-up data of Japanese and non-Japanese patients with TIA or minor stroke.

METHODS

Patients with TIA or minor ischemic stroke within 7 days after the onset were classified into two groups based on ethnicity, Japanese (n=345) and non-Japanese (n=3502); further, 5-year event rates were compared between the two groups. We also determined predictors of 5-year stroke for both groups.

RESULTS

Vascular death and death from any cause were identified to be less prevalent, unlike stroke and intracranial hemorrhage, which was determined to be more prevalent in Japanese than in non-Japanese patients. Five-year rate of stroke was significantly higher in Japanese patients. Cumulative stroke and major cardiovascular event rates did not decline but instead linearly increased from 1 to 5 years in both groups. Baseline risk factors for 5-year stroke were as follows: age, diabetes, history of stroke or TIA, and congestive heart failure in Japanese patients. Independent predictors of 5-year stroke were large artery atherosclerosis, congestive heart failure, diabetes, and age in Japanese patients.

CONCLUSIONS

Recurrent stroke and intracranial hemorrhage were determined to be more prevalent at 5 years after TIA or minor stroke in Japanese patients than in non-Japanese patients. Strategies to mitigate the long-term risks of stroke, aside from adherence to current guidelines, should take Japanese-patient-specific residual risks into account.

Transient ischemic attack without self-awareness of symptoms witnessed by bystanders: analysis of the PROMISE-TIA registry

Background and purpose

A transient ischemic attack (TIA) can occur without self‐awareness of symptoms. We aimed to investigate characteristics of patients with a tissue‐based diagnosis of TIA but having no self‐awareness of their symptoms and whose symptoms were witnessed by bystanders.

Methods

We used data from the multicenter registry of 1414 patients with a clinical diagnosis of TIA. For patients without evidence of ischemic lesions on imaging, clinical characteristics were compared between patients with and without self‐awareness of their TIA symptoms.

Results

Among 896 patients (559 men, median age of 70 years), 59 (6.6%) were unaware of their TIA symptoms, but had those symptoms witnessed by bystanders. Patients without self‐awareness of symptoms were older and more frequently female, and more likely to have previous history of stroke, premorbid disability, and atrial fibrillation, but less likely to have dyslipidemia than those with self‐awareness. Patients without self‐awareness of symptoms arrive at hospitals earlier than those with self‐awareness (P < 0.001). ABCD² score was higher in patients without self‐awareness of symptoms than those with self‐awareness (median 5 vs. 4, P = 0.002). Having no self‐awareness of symptoms was a significant predictor of ischemic stroke within 1 year after adjustment for sex, ABCD² score, and onset to arrival time (hazard ratio = 2.44, 95% confidential interval: 1.10–4.83), but was not significant after further adjustment for arterial stenosis or occlusion.

Conclusions

Patients with a TIA but having no self‐awareness of their symptoms might have higher risk of subsequent ischemic stroke rather than those with self‐awareness, suggesting urgent management is needed even if patients have no self‐awareness of symptoms.

Prospective Study About the Relationship Between CEUS of Carotid Intraplaque Neovascularization and Ischemic Stroke in TIA Patients

Objective: To evaluate the relationship between contrast-enhanced ultrasonography (CEUS) of carotid intraplaque neovascularization and ischemic stroke in transient ischemic attack (TIA) patients. Methods: A total of 112 TIA patients were selected for the study. Routine carotid ultrasonic examination was performed for all the patients. CEUS was carried out for consecutive patients with plaque thicker than 2.5 mm in carotid bifurcation and follow-up for at least 24 months. The number of patients with incurrence of ischemic stroke or recurrence of TIA was obtained during the follow-up period. To detect the risk factors for incurrence of ischemic stroke or recurrence of TIA in 24 months, multivariate logistic regression analyses were performed for all the risk factors in all the selected patients. Results: Ninety-one patients underwent CEUS and were followed up at least 24 months. There were statistical differences between recurrent and non-recurrent groups about hypertension, diabetes, hyperlipemia, smoking history, family history of stroke, medication compliance, two-dimensional ultrasound, and CEUS (P < 0.05). The higher CEUS intensity in the carotid plaque was, the higher was the possibility of ischemic stroke or recurrent TIA. Multivariate logistic regression analysis showed that the CEUS characteristics of carotid plaque such as linear enhancement or diffuse enhancement were independent risk factors for ischemic stroke or recurrent TIA in TIA patients (P < 0.05). Conclusion: For carotid plaques, CEUS could evaluate the infusion mode, which could reflect the neovascularization in plaques. CEUS could predict the incurrence of ischemic stroke or recurrence of TIA in TIA patients, which is useful information when making a clinical decision.

Small vessel occlusion is a high-risk etiology for early recurrent stroke after transient ischemic attack

Background

Recent prospective registration studies of transient ischemic attack in Western countries demonstrated that large artery atherosclerosis is the highest risk etiology for early stroke recurrence under urgent evaluation and treatment. On the other hand, some limited transient ischemic attack studies from East Asian countries showed transient ischemic attack patients due to small vessel occlusion were at a higher early stroke risk.

Aims

We aimed to assess the risk for early stroke in small vessel occlusion-transient ischemic attack patients in a Japanese large transient ischemic attack registry.

Methods

We analyzed the data of a prospective Japanese transient ischemic attack registry including 1320 transient ischemic attack patients within seven days after onset. Small vessel occlusion-transient ischemic attack was defined as the presence of lacunar transient ischemic attack syndrome, without other etiologies. The outcome measure was recurrent stroke within 30 days after transient ischemic attack. The predictors of 30-day recurrent stroke were estimated using the Cox proportional hazards model.

Results

The study population had a mean age of 69 ± 12 years and 470 were women. Recurrent stroke was observed in 61 patients (4.6%), and the highest rate was observed with small vessel occlusion-transient ischemic attack (7.8%), followed by large artery atherosclerosis (5.4%). In multivariate analysis, recurrent stroke was independently associated with small vessel occlusion-transient ischemic attack (hazard ratio (HR): 2.01, 95% confidence interval (CI): 1.19–3.35), higher systolic blood pressure (HR: 1.18, 95% CI: 1.08–1.28), and presentation within 3 h after onset (HR: 2.21, 95% CI: 1.27–4.04). Furthermore, small vessel occlusion-transient ischemic attack with acute small deep infarct on diffusion-weighted imaging was a stronger predictor of recurrent stroke (HR: 4.87, 95% CI: 2.09–10.0).

Conclusion

Small vessel occlusion-transient ischemic attack, especially with acute small deep infarct, had a higher early stroke risk compared with other etiologies in Japanese transient ischemic attack patients who received early management.

Significance of Nonfocal Symptoms in Patients With Transient Ischemic Attack

Background and Purpose- Patients with transient ischemic attack (TIA) occasionally show nonfocal symptoms, such as unconsciousness, amnesia, and unsteadiness. The purpose of this study was to clarify the characteristics and prognosis of patients with TIA with nonfocal symptoms, using data from the PROMISE-TIA (Prospective Multicenter Registry to Identify Subsequent Cardiovascular Events After Transient Ischemic Attack). Methods- Patients with TIA within 7 days of onset were consecutively enrolled in the Japanese nationwide registry. Factors associated with nonfocal symptoms and 1-year risks of ischemic stroke and coronary artery diseases were assessed in multivariate-adjusted models. Results- We studied 1362 patients with TIA (879 men; mean age, 69±12 years), including 219 (16%) with nonfocal symptoms. Patients with TIA with nonfocal symptoms were more likely to show acute ischemic lesions in the posterior circulation on diffusion-weighted imaging (multivariate-adjusted odds ratio, 3.07; 95% confidence interval, 1.57-5.82) and arterial stenosis or occlusion in the posterior circulation on vascular examination (odds ratio, 1.94; 95% confidence interval, 1.19-3.09) than those without nonfocal symptoms. Although 1-year risk of ischemic stroke did not differ significantly between groups (adjusted hazard ratio, 0.79; 95% confidence interval, 0.42-1.37), risk of coronary artery disease was higher in patients with TIA with nonfocal symptoms (hazard ratio, 3.37; 95% confidence interval, 1.14-9.03). Conclusions- Both acute ischemic lesions and arterial stenosis and occlusion in the posterior circulation were more frequently observed in patients with TIA with nonfocal symptoms.

Transient ischemic attack and ischemic stroke patients with or without prior stroke

OBJECTIVES

A history of stroke is common in patients with transient ischemic attack (TIA) and ischemic stroke (IS), but there are few reports characterizing this group of patients. We aimed to compare characteristics, risk factors, and secondary preventive treatment in patients with TIA or IS with vs without a history of stroke.

METHODS

Hospital-based data on TIA and IS events, registered from July 2011 to June 2013, were obtained from the Swedish Stroke Register (Riksstroke). Previous stroke was not specified as hemorrhagic or ischemic.

RESULTS

A history of stroke was present in 19.3% (2892/15012) of TIA and 24.6% (10853/44169) of IS patients. Patients with prior stroke were older, more often male, and more likely to have atrial fibrillation (AF) (TIA: 27.4% vs 16.4%; IS: 36.1% vs 28.0%), hypertension (TIA: 77.5% vs 56.4%; IS: 74.2% vs 59.0%), and diabetes mellitus (TIA: 22.2% vs 14.2%; IS: 26.3% vs 19.5%) compared with those without (all differences P<.0001). At discharge, patients with prior stroke were more often treated with antihypertensive drugs than those without, whereas proportions treated with statins were similar in both groups. Patients with AF and prior stroke were less often treated with oral anticoagulant (OAC) medication than those without prior stroke.

CONCLUSIONS

Both in TIA and IS, vascular risk factors were more common in patients with a history of stroke compared with those without. In contrast to other secondary preventive medications, OAC treatment in the presence of AF was underutilized in patients with a history of stroke.