Coronary Artery Disease in Patients Presenting With Acute Ischemic Stroke or Transient Ischemic Attack and Elevated Troponin Levels

Background: There is little information concerning the invasive coronary angiography (ICA) findings of patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) with elevated troponin levels and suspected myocardial infarction (MI). This study analyzed patient characteristics associated with ICA outcomes.Methods: A total of 8,322 patients with AIS or TIA, treated between March 2010 and May 2020, were retrospectively screened for elevated serum troponin I at hospital admission. Patients in whom ICA was performed, due to suspected type 1 MI based on symptoms, echocardiography, and ECG, were categorized according to ICA results (non-obstructive coronary artery disease (CAD): ≥1 stenosis ≥50% but no stenosis ≥80%; obstructive CAD: any stenosis ≥80% or hemodynamically relevant stenosis assessed by FFR/iwFR).Results: Elevated troponin levels were detected in 2,205 (22.5%) patients, of whom 123 (5.6%) underwent ICA (mean age 71 ± 12 years; 67% male). CAD was present in 98 (80%) patients, of whom 51 (41%) were diagnosed with obstructive CAD. Thus, ICA findings of obstructive CAD accounted for 2.3% of patients with troponin elevation and 0.6% of all stroke patients. The clinical hallmarks of myocardial ischemia, including angina pectoris (31 vs. 15%, p < 0.05) and regional wall motion abnormalities (49 vs. 32%, p = 0.07), and increased cardiovascular risk indicated obstructive CAD. While there was no association between lesion site or stroke severity and ICA findings, causal large-artery atherosclerosis was significantly more common in patients with obstructive coronary disease (p < 0.05).Conclusion: The rate of obstructive CAD in patients with stroke or TIA and elevated troponin levels with suspected concomitant type I MI is low. The cumulation of several cardiovascular risk factors and clinical signs of MI were predictive. AIS patients with large-artery atherosclerosis and elevated troponin may represent an especially vulnerable subgroup of stroke patients with risk for obstructive CAD.

Atrial Fibrillation and Stroke Symptoms in the REGARDS Study

Background It is unknown if stroke symptoms in the absence of a stroke diagnosis are a sign of subtle cardioembolic phenomena. The objective of this study was to examine associations between atrial fibrillation (AF) and stroke symptoms among adults with no clinical history of stroke or transient ischemic attack (TIA). Methods and Results We evaluated associations between AF and self‐reported stroke symptoms in the national, prospective REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort. We conducted cross‐sectional (n=27 135) and longitudinal (n=21 932) analyses over 8 years of follow‐up of REGARDS participants without stroke/transient ischemic attack and stratified by anticoagulant or antiplatelet agent use. The mean age was 64.4 (SD±9.4) years, 55.3% were women, and 40.8% were Black participants; 28.6% of participants with AF reported stroke symptoms. In the cross‐sectional analysis, comparing participants with and without AF, the risk of stroke symptoms was elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (odds ratio [OR], 2.22; 95% CI, 1.89–2.59) or antiplatelet agents only (OR, 1.92; 95% CI, 1.61–2.29) but not for adults with AF taking anticoagulants (OR, 1.08; 95% CI, 0.71–1.65). In the longitudinal analysis, the risk of stroke symptoms was also elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (hazard ratio [HR], 1.41; 95% CI, 1.21–1.66) or antiplatelet agents only (HR, 1.23; 95% CI, 1.04–1.46) but not for adults with AF taking anticoagulants (HR, 0.86; 95% CI, 0.62–1.18). Conclusions Stroke symptoms in the absence of a stroke diagnosis may represent subclinical cardioembolic phenomena or “whispering strokes.” Future studies examining the benefit of stroke symptom screening may be warranted.

Validation of CSR model to predict stroke risk after transient ischemic attack

It is essential to identify high risk transient ischemic attack (TIA) patients. The previous study reported that the CSR (comprehensive stroke recurrence) model, a neuroimaging model, had a high predictive ability of recurrent stroke. The aims of this study were to validate the predictive value of CSR model in TIA patients and compare the predictive ability with ABCD3-I score. Data were analyzed from the prospective hospital-based database of patients with TIA which defined by the World Health Organization time-based criteria. The predictive outcome was stroke occurrence at 90 days. The receiver-operating characteristic (ROC) curves were plotted and the C statistics were calculated as a measure of predictive ability. Among 1186 eligible patients, the mean age was 57.28 ± 12.17 years, and 474 (40.0%) patients had positive diffusion-weighted imaging (DWI). There were 118 (9.9%) patients who had stroke within 90 days. In 1186 TIA patients, The C statistic of CSR model (0.754; 95% confidence interval [CI] 0.729–0.778) was similar with that of ABCD3-I score (0.717; 95% CI 0.691–0.743; Z = 1.400; P = 0.1616). In 474 TIA patients with positive DWI, C statistic of CSR model (0.725; 95% CI 0.683–0.765) was statistically higher than that of ABCD3-I score (0.626; 95% CI 0.581–0.670; Z = 2.294; P = 0.0245). The CSR model had good predictive value for assessing stroke risk after TIA, and it had a higher predictive value than ABCD3-I score for assessing stroke risk for TIA patients with positive DWI.

Atrial Fibrillation Detected After Stroke and Transient Ischemic Attack: A Novel Clinical Concept Challenging Current Views

Atrial fibrillation (AF) can be newly detected in approximately one-fourth of patients with ischemic stroke and transient ischemic attack without previously recognized AF. We present updated evidence supporting that AF detected after stroke or transient ischemic attack (AFDAS) may be a distinct clinical entity from AF known before stroke occurrence (known atrial fibrillation). Data suggest that AFDAS can arise from the interplay of cardiogenic and neurogenic forces. The embolic risk of AFDAS can be understood as a gradient defined by the prevalence of vascular comorbidities, the burden of AF, neurogenic autonomic changes, and the severity of atrial cardiopathy. The balance of existing data indicates that AFDAS has a lower prevalence of cardiovascular comorbidities, a lower degree of cardiac abnormalities than known atrial fibrillation, a high proportion (52%) of very brief (<30 seconds) AF paroxysms, and is more frequently associated with insular brain infarction. These distinctive features of AFDAS may explain its recently observed lower associated risk of stroke than known atrial fibrillation. We present an updated ad-hoc meta-analysis of randomized clinical trials in which the association between prolonged cardiac monitoring and reduced risk of ischemic stroke was nonsignificant (incidence rate ratio, 0.90 [95% CI, 0.71–1.15]). These findings highlight that larger and sufficiently powered randomized controlled trials of prolonged cardiac monitoring assessing the risk of stroke recurrence are needed. Meanwhile, we call for further research on AFDAS and stroke recurrence, and a tailored approach when using prolonged cardiac monitoring after ischemic stroke or transient ischemic attack, focusing on patients at higher risk of AFDAS and, more importantly, at higher risk of cardiac embolism.

Transient Ischemic Attack

The transient ischemic attack is a neurological emergency which is a clinical view of focal cerebral, retinal, or spinal dysfunction that lasts less than an hour, without any detectable acute infarction in neurological imaging methods. TIA is a serious warning for ischemic stroke, and this risk is particularly high in the first 48 hours. Following TIAs, approximately 10-15% of patients undergo stroke in 90 days and about half of these patients suffer a stroke in the first two days. Neuroimaging and laboratory studies should be performed quickly to reveal the etiology and to reduce the risk of stroke that may develop in patients present with TIA. Therapeutic and preventive interventions should be started as soon as possible. With early diagnosis and treatment, the risk of a 90-day stroke in these patients can be reduced by 80%. In addition to antiplatelet and anticoagulant treatments, aggressive control of blood pressure, regulation of blood sugar, statin, dietary recommendations, exercise, and managing the other underlying specific conditions should be started quickly.