Clinical scores for predicting recurrence after transient ischemic attack or stroke: how good are they?

Symptomatic Carotid Atheroma Inflammation Lumen-stenosis score compared with Oxford and Essen risk scores to predict recurrent stroke in symptomatic carotid stenosis

BACKGROUND

The Oxford Carotid Stenosis tool (OCST) and Essen Stroke Risk Score (ESRS) are validated to predict recurrent stroke in patients with and without carotid stenosis. The Symptomatic Carotid Atheroma Inflammation Lumen stenosis (SCAIL) score combines stenosis and plaque inflammation on fluorodeoxyglucose positron-emission tomography (18FDG-PET). We compared SCAIL with OCST and ESRS to predict ipsilateral stroke recurrence in symptomatic carotid stenosis.

PATIENTS AND METHODS

We pooled three prospective cohort studies of patients with recent (<30 days) non-severe ischaemic stroke/TIA and internal carotid artery stenosis (>50%). All patients had carotid 18FDG-PET/CT angiography and late follow-up, with censoring at carotid revascularisation.

RESULTS

Of 212 included patients, 16 post-PET ipsilateral recurrent strokes occurred in 343 patient-years follow-up (median 42 days (IQR 13-815)).Baseline SCAIL predicted recurrent stroke (unadjusted hazard ratio [HR] 1.96, CI 1.20-3.22, p = 0.007, adjusted HR 2.37, CI 1.31-4.29, p = 0.004). The HR for OCST was 0.996 (CI 0.987-1.006, p = 0.49) and for ESRS was 1.26 (CI 0.87-1.82, p = 0.23) (all per 1-point score increase). C-statistics were: SCAIL 0.66 (CI 0.51-0.80), OCST 0.52 (CI 0.40-0.64), ESRS 0.61 (CI 0.48-0.74). Compared with ESRS, addition of plaque inflammation (SUVmax) to ESRS improved risk prediction when analysed continuously (HR 1.51, CI 1.05-2.16, p = 0.03) and categorically (ptrend = 0.005 for risk increase across groups; HR 3.31, CI 1.42-7.72, p = 0.006; net reclassification improvement 10%). Findings were unchanged by further addition of carotid stenosis.

CONCLUSIONS

SCAIL predicted recurrent stroke, had discrimination better than chance, and improved the prognostic utility of ESRS, suggesting that measuring plaque inflammation may improve risk stratification in carotid stenosis.

Predictors of very early stroke recurrence in the POINT trial population

Background

Recent trials of acute secondary prevention in patients with minor ischemic stroke or transient ischemic attack (TIA) have demonstrated high rates of early recurrence within days of the initial event. Identifying clinical features associated with early recurrence may guide focused management.

Methods

Using logistic regression applied to the data of the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, we evaluated what baseline clinical factors predict outcome events occurring within 7 days of randomization.

Results

In the POINT trial, 181 subjects (3.7%) had early recurrence, defined as primary outcome events within 7 days of trial entry, whereas only 100 outcome events occurred over the remainder of the 90 day trial. Protective effects of dual antiplatelet therapy with clopidogrel plus aspirin were seen only as a reduction in these early recurrences, without any impact on later events. In univariate analysis, systolic blood pressure, diastolic blood pressure, serum glucose, initial carotid imaging results, study cohort (minor stroke or TIA), and treatment assignment were significantly associated with early recurrence. Multivariate logistic regression analysis identified a number of factors with significant independent associations with early recurrence, including carotid stenosis or occlusion (Odds Ratio [OR] 2.77; 95% confidence interval [CI] 1.78–4.31), cohort (minor stroke versus TIA) (OR 1.86; 95% CI 1.33–2.58), race (OR 1.57; 95% CI 1.10–2.25), baseline statin use (OR 0.68; 95% CI 0.49–0.95), systolic blood pressure (OR 1.10; 95% CI 1.03–1.18), serum glucose (OR 1.03; 95% CI 1.01–1.05), and age (OR 1.02; 95% CI 1.00–1.03). Receiver Operator Characteristic (ROC) analysis showed a 70% accuracy of the resulting logistic model in predicting early recurrence.

Conclusions

Early recurrence is high, and is concentrated in the first 7 days, in patients with minor stroke or TIA. A number of baseline clinical factors, including carotid disease, presentation with minor stroke rather than TIA, race, absence of statin usage, systolic blood pressure, and serum glucose, are independently associated with early event recurrence in the POINT trial population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02703-4.

Balancing Benefits and Risks of Long-Term Antiplatelet Therapy in Noncardioembolic Transient Ischemic Attack or Stroke

BACKGROUND AND PURPOSE

Lifelong treatment with antiplatelet drugs is recommended following a transient ischemic attack or ischemic stroke. Bleeding complications may offset the benefit of antiplatelet drugs in patients at increased risk of bleeding and low risk of recurrent ischemic events. We aimed to investigate the net benefit of antiplatelet treatment according to an individuals' bleeding risk.

METHODS

We pooled individual patient data from 6 randomized clinical trials (CAPRIE [Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events], ESPS-2 [European Stroke Prevention Study-2], MATCH [Management of Atherothrombosis With Clopidogrel in High-Risk Patients], CHARISMA [Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance], ESPRIT [European/Australasian Stroke Prevention in Reversible Ischemia Trial], and PRoFESS [Prevention Regimen for Effectively Avoiding Second Strokes]) investigating antiplatelet therapy in the subacute or chronic phase after noncardioembolic transient ischemic attack or stroke. Patients were stratified into quintiles according to their predicted risk of major bleeding with the S₂TOP-BLEED score. The annual risk of major bleeding and recurrent ischemic events was assessed per quintile for 4 scenarios: (1) aspirin monotherapy, (2) aspirin-clopidogrel versus aspirin or clopidogrel monotherapy, (3) aspirin-dipyridamole versus clopidogrel, and (4) aspirin versus clopidogrel. Net benefit was calculated for the second, third, and fourth scenario.

RESULTS

Thirty seven thousand eighty-seven patients were included in the analyses. Both risk of major bleeding and recurrent ischemic events increased over quintiles of predicted bleeding risk, but risk of ischemic events was consistently higher (eg, from 0.7%/y (bottom quintile) to 3.2%/y (top quintile) for major bleeding on aspirin and from 2.5%/y to 10.2%/y for risk of ischemic events on aspirin). Treatment with aspirin-clopidogrel led to more major bleedings (0.9%-1.7% per year), than reduction in ischemic events (ranging from 0.4% to 0.9/1.0% per year) across all quintiles. There was no clear preference for either aspirin-dipyridamole or clopidogrel according to baseline bleeding risk.

CONCLUSIONS

Among patients with a transient ischemic attack or ischemic stroke included in clinical trials of antiplatelet therapy, the risk of recurrent ischemic events and of major bleeding increase in parallel. Antiplatelet treatment cannot be individualized solely based on bleeding risk assessment.

Early Identification of High-Risk TIA or Minor Stroke Using Artificial Neural Network

Background and Purpose: The risk of recurrent stroke following a transient ischemic attack (TIA) or minor stroke is high, despite of a significant reduction in the past decade. In this study, we investigated the feasibility of using artificial neural network (ANN) for risk stratification of TIA or minor stroke patients.

Methods: Consecutive patients with acute TIA or minor ischemic stroke presenting at a tertiary hospital during a 2-year period were recruited. We collected demographics, clinical and imaging data at baseline. The primary outcome was recurrent ischemic stroke within 1 year. We developed ANN models to predict the primary outcome. We randomly down-sampled patients without a primary outcome to 1:1 match with those with a primary outcome to mitigate data imbalance. We used a 5-fold cross-validation approach to train and test the ANN models to avoid overfitting. We employed 19 independent variables at baseline as the input neurons in the ANN models, using a learning algorithm based on backpropagation to minimize the loss function. We obtained the sensitivity, specificity, accuracy and the c statistic of each ANN model from the 5 rounds of cross-validation and compared that of support vector machine (SVM) and Naïve Bayes classifier in risk stratification of the patients.

Results: A total of 451 acute TIA or minor stroke patients were enrolled. Forty (8.9%) patients had a recurrent ischemic stroke within 1 year. Another 40 patients were randomly selected from those with no recurrent stroke, so that data from 80 patients in total were used for 5 rounds of training and testing of ANN models. The median sensitivity, specificity, accuracy and c statistic of the ANN models to predict recurrent stroke at 1 year was 75%, 75%, 75%, and 0.77, respectively. ANN model outperformed SVM and Naïve Bayes classifier in our dataset for predicting relapse after TIA or minor stroke.

Conclusion: This pilot study indicated that ANN may yield a novel and effective method in risk stratification of TIA and minor stroke. Further studies are warranted for verification and improvement of the current ANN model.

GRECOS Project (Genotyping Recurrence Risk of Stroke): The Use of Genetics to Predict the Vascular Recurrence After Stroke

BACKGROUND AND PURPOSE

Vascular recurrence occurs in 11% of patients during the first year after ischemic stroke (IS) or transient ischemic attack. Clinical scores do not predict the whole vascular recurrence risk; therefore, we aimed to find genetic variants associated with recurrence that might improve the clinical predictive models in IS.

METHODS

We analyzed 256 polymorphisms from 115 candidate genes in 3 patient cohorts comprising 4482 IS or transient ischemic attack patients. The discovery cohort was prospectively recruited and included 1494 patients, 6.2% of them developed a new IS during the first year of follow-up. Replication analysis was performed in 2988 patients using SNPlex or HumanOmni1-Quad technology. We generated a predictive model using Cox regression (GRECOS score [Genotyping Reurrence Risk of Stroke]) and generated risk groups using a classification tree method.

RESULTS

The analyses revealed that rs1800801 in the MGP gene (hazard ratio, 1.33; P=9×10^-03), a gene related to artery calcification, was associated with new IS during the first year of follow-up. This polymorphism was replicated in a Spanish cohort (n=1.305); however, it was not significantly associated in a North American cohort (n=1.683). The GRECOS score predicted new IS (P=3.2×10^-09) and could classify patients, from low risk of stroke recurrence (1.9%) to high risk (12.6%). Moreover, the addition of genetic risk factors to the GRECOS score improves the prediction compared with previous Stroke Prognosis Instrument-II score (P=0.03).

CONCLUSIONS

The use of genetics could be useful to estimate vascular recurrence risk after IS. Genetic variability in the MGP gene was associated with vascular recurrence in the Spanish population.

Predicting outcomes after transient ischemic attack and stroke

PURPOSE OF REVIEW

Predicting functional outcome and mortality after stroke, with or without thrombolysis, is a critical role of neurologists. This article reviews the predictors of outcome after ischemic stroke.

RECENT FINDINGS

Several scores were recently designed to predict (1) mortality and poor functional outcome after ischemic stroke, (2) the functional outcome and risk of symptomatic intracranial hemorrhage (sICH) after thrombolysis, and (3) the risk of stroke following TIA. Validation of these prediction instruments is ongoing, and studies will be critical to determine the general applicability of these scores.

SUMMARY

Although several scores were developed to predict mortality and outcome after stroke, it may be premature to employ these prediction scores to determine individual patient outcome. Similarly, prediction scores should not be used to deny patients tissue plasminogen activator (tPA), even if the scores predict that the patient has a high likelihood of sICH or poor outcome after thrombolysis.

Secondary prevention of ischaemic stroke

In spite of a documented reduction in incidence in high-income countries over the last decades, stroke is still a leading cause of death and disability worldwide. With the ageing of the population stroke-related economic burden is expected to increase, because of residual disability and its complications, such as cognitive impairment, high risk of falls and fractures, depression and epilepsy. Furthermore, because of the substantial rate of early and long-term vascular recurrences after the first event, secondary prevention after cerebral ischaemia is a crucial issue. This is even more important after minor stroke and transient ischaemic attack (TIA), in order to reduce the risk of potentially more severe and disabling events. To accomplish this aim, acute long-term medical and surgical treatments as well as lifestyle modifications are strongly recommended. However, apart from the well-established indications to thrombolysis, studies in acute phase after a first stroke or TIA are scarce and evidence is lacking. More trials are available for long-term secondary prevention with different classes of drugs, including antithrombotic medications for ischaemic events of arterial and cardiac origin, especially related to atrial fibrillation (antiplatelets and anticoagulants, respectively), lipid lowering agents (mainly statins), blood pressure lowering drugs, surgical and endovascular revascularization procedures.