Abstract 3530: Low yield of Transthoracic and Transesophageal Echocardiography in the Management of Patients with Acute Ischemic Strokes
Bibliographic record
Abstract
Background Echocardiography has become ubiquitous in the diagnostic armamentarium of ischemic strokes. There is however insufficient evidence to recommend transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in every patient with ischemic stroke. We sought to determine diagnostic yield of TTE and TEE in determining cardiac etiology for ischemic strokes. Methods This is a retrospective chart review of patients with diagnosis of ischemic stroke admitted to the Foothills Medical Center, Calgary from Jan 2009 to June 2010. These patients had TTE and/or a TEE as part of inpatient diagnostic evaluation. Patients with previous history of atrial fibrillation and anticoagulation were excluded. Clinical findings,baseline cardiac exam and ECG were noted. High yield findings on TTE and TEE were defined using American Heart association guidelines( mitral stenosis,LV/LA thrombus/aneurysym,apical akinesia/septal aneurysym,severe LV dysfunction,ASD,vegetation).Topographical distribution of infarcts on follow-up brain imaging and vascular imaging findings within 7 days after the event were documented. These imaging findings were categorized in following groups: normal, infarcts with presumed cardioembolic source (single cortical, multiple cortical, bilateral infarcts with normal vascular imaging), lacune (single subcortical) and infarcts due to large artery atherosclerosis (single or multiple infarcts in the territory of an abnormal large artery). Results 397 patients with TTE and 67 with TTE/TEE as a workup for ischemic stroke were included in the study. High yield TTE findings were seen in 34/397(8.6%) patients. High yield TEE findings were found in 5/65 (7.7%) patients. Thirteen of 34 (38%) patients with high yield TTE findings had abnormal ECG or baseline cardiac exam at presentation in comparison to 10/423(2%) patients with no high yield findings (p=0.02). There was a suggestion that imaging patterns with presumed cardioembolic source showed association with high yield TTE findings [19/39 (50%) patients in comparison to 144/423(19%)] patients with no high yield findings.(p=0.07 OR 1.84 95% CI 0.95-3.84). Among the various topographical patterns, single cortical infarct with normal vascular imaging was significantly associated with high yield TTE findings. (p<0.03, OR 2.20 95% CI 1.04 - 4.64). Conclusion The diagnostic yield of TTE and TEE in determining cardio-embolic sources is relatively low. Baseline abnormal ECG and clinical exam along with specific patterns of imaging may help to determine cardioembolic etiology. A more rational approach to use of cardiac imaging is required in settings with limited resources.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.009 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".