Prolonged Cardiac Rhythm Monitoring and Secondary Stroke Prevention in Patients With Cryptogenic Cerebral Ischemia.

Background and Purpose- Although prolonged cardiac rhythm monitoring (PCM) can reveal a substantial proportion of ischemic stroke (IS) patients with atrial fibrillation not detected by conventional short-term monitoring, current guidelines indicate an uncertain clinical benefit for PCM. We evaluated the impact of PCM on secondary stroke prevention using data from available to date randomized clinical trials and observational studies. Methods- We performed a comprehensive literature search in MEDLINE, SCOPUS, CENTRAL (Cochrane Central Register of Controlled Trial), and conference proceedings to identify studies reporting stroke recurrence rates in patients with history of cryptogenic IS or transient ischemic attack (TIA) receiving PCM compared with patients receiving conventional (non-PCM) cardiac monitoring. Results- We included 4 studies (2 randomized clinical trials and 2 observational studies), including a total of 1102 patients (mean age: 68 years, 41% women). We documented an increased incidence of atrial fibrillation detection (risk ratio=2.46; 95% CI, 1.61-3.76) and anticoagulant initiation (risk ratio=2.07; 95% CI, 1.36-3.17) and decreased risk of recurrent stroke (risk ratio=0.45; 95% CI, 0.21-0.97) and recurrent stroke/TIA (risk ratio=0.49; 95% CI, 0.30-0.81) during follow-up for IS/TIA patients who underwent PCM compared with IS/TIA patients receiving conventional cardiac monitoring. In the subgroup analysis, according to study type, atrial fibrillation detection, anticoagulant initiation, and IS/TIA recurrence rates were comparable between PCM and non-PCM in randomized clinical trials and observational studies. No evidence of heterogeneity (I2<12%) was documented across all the aforementioned subgroups. Conclusions- We provide preliminary evidence for a potential impact of PCM on secondary stroke prevention, as patients with cryptogenic IS/TIA undergoing PCM had higher rates of atrial fibrillation detection, anticoagulant initiation, and lower stroke recurrence.

Troponin Improves the Yield of Transthoracic Echocardiography in Ischemic Stroke Patients of Determined Stroke Subtype.

Background and Purpose- Transthoracic echocardiography (TTE) is widely used in the ischemic stroke setting. In this study, we aim to investigate the yield of TTE in patients with ischemic stroke and known subtype and whether the admission troponin level improves the yield of TTE. Methods- Data were abstracted from a single-center prospective ischemic stroke database for 18 months and included all patients with ischemic stroke whose etiologic subtype could be obtained without the need of TTE. Unadjusted and adjusted regression models were built to determine whether positive cardiac troponin levels (≥0.1 ng/mL) improve the yield of TTE, adjusting for demographic and clinical characteristics. Results- We identified 578 patients who met the inclusion criteria. TTE changed clinical management in 64 patients (11.1%), but intracardiac thrombus was detected in only 4 patients (0.7%). In multivariable models, there was an association between TTE changing management and positive serum troponin level (adjusted odds ratio, 4.26; 95% CI, 2.17-8.34; P<0.001). Conclusions- In patients with ischemic stroke, TTE might lead to a change in clinical management in ≈1 of 10 patients with known stroke subtype before TTE but changed acute treatment decisions in <1 percent of patients. Serum troponin levels improved the yield of TTE in these patients.

Early Elevated Troponin Levels After Ischemic Stroke Suggests a Cardioembolic Source.

BACKGROUND AND PURPOSE: Elevated cardiac troponin is a marker of cardiac disease and has been recently shown to be associated with embolic stroke risk. We hypothesize that early elevated troponin levels in the acute stroke setting are more prevalent in patients with embolic stroke subtypes (cardioembolic and embolic stroke of unknown source) as opposed to noncardioembolic subtypes (large-vessel disease, small-vessel disease, and other). METHODS: We abstracted data from our prospective ischemic stroke database and included all patients with ischemic stroke during an 18-month period. Per our laboratory, we defined positive troponin as ≥0.1 ng/mL and intermediate as ≥0.06 ng/mL and <0.1 ng/mL. Unadjusted and adjusted regression models were built to determine the association between stroke subtype (embolic stroke of unknown source and cardioembolic subtypes) and positive and intermediate troponin levels, adjusting for key confounders, including demographics (age and sex), clinical characteristics (hypertension, hyperlipidemia, diabetes mellitus, renal function, coronary heart disease, congestive heart failure, current smoking, and National Institutes of Health Stroke Scale score), cardiac variables (left atrial diameter, wall-motion abnormalities, ejection fraction, and PR interval on ECG), and insular involvement of infarct. RESULTS: We identified 1234 patients, of whom 1129 had admission troponin levels available; 10.0% (113/1129) of these had a positive troponin. In fully adjusted models, there was an association between troponin positivity and embolic stroke of unknown source subtype (adjusted odds ratio, 4.46; 95% confidence interval, 1.03-7.97; P=0.003) and cardioembolic stroke subtype (odds ratio, 5.00; 95% confidence interval, 1.83-13.63; P=0.002). CONCLUSIONS: We found that early positive troponin after ischemic stroke may be independently associated with a cardiac embolic source. Future studies are needed to confirm our findings using high-sensitivity troponin assays and to test optimal secondary prevention strategies in patients with embolic stroke of unknown source and positive troponin.