The CATCH ME study is a prospective, multicenter, observational, no-profit study aimed at improving embolic risk stratification in patients with embolic stroke of undetermined source (ESUS), particularly in those with left ventricular disease (LVD). LVD is defined by a mildly to moderately reduced ejection fraction (30-49%), left ventricular wall motion abnormalities (hypo/akinesia), ventricular dilation, cardiomyopathies, and other related conditions. In these patients, the intermittent formation of intracardiac thrombi within the ventricle, often undetectable by standard diagnostic evaluation such as transthoracic echocardiography (TTE) alone, may serve as an unrecognized embolic source. However, in clinical practice, such patients are frequently discharged on antiplatelet therapy alone, without adequate thromboembolic risk stratification, thus leaving them at a high risk of ischemic recurrence. This study aims to assess the additional diagnostic value of advanced cardiac imaging - Cardiac Magnetic Resonance Imaging (CMRI) and/or Cardiac Computed Tomography (CCT) - in detecting intracardiac thrombi not identified by TTE in patients with ESUS and LVD.
Age between 18 and 85 years Modified Rankin Scale (mRS) score ≤ 4 Diagnosis of acute ischemic stroke (detected by CT or brain MRI) Diagnosis of ESUS according to standard criteria
Stroke detected by CT or MRI that is not lacunar. Lacunar is defined as a subcortical infarction (including pons and mesencephalon) in the distribution of the small penetrating cerebral arteries, with a maximum size ≤ 1.5 cm on CT or ≤ 2.0 cm on diffusion-weighted MRI images (< 1.5 cm on T2-weighted MRI images). Excluded: multiple small deep infarcts, lateral bulb infarcts, cerebellar infarcts, patients with clinical lacunar stroke syndrome and no visible infarction on imaging.
Absence of extracranial or intracranial atherosclerosis causing ≥ 50% stenosis in the artery supplying the ischemic area. Vascular imaging of the extracranial and intracranial vessels is required using angiography, CT angiography (CTA), MR angiography (MRA), or color Doppler ultrasound, at the discretion of the treating physician and local principal investigator.
No major cardioembolic source identified, including permanent or paroxysmal atrial fibrillation (AF), sustained atrial flutter, intracardiac thrombus (*as specified above, these patients will be recruited in phase 1 of the study only if an isolated ventricular thrombus is found without other major cardiac causes), mechanical heart valve prosthesis, atrial myxoma or other cardiac tumors, moderate or severe mitral stenosis, recent myocardial infarction (< 4 weeks), left ventricular ejection fraction (EF) < 30%, valve vegetations or infective endocarditis.
Major cardioembolic sources, as specified in the ESUS criteria Patients with a thrombophilic state secondary to active cancer, defined as "diagnosis of solid or hematologic malignant tumor within 6 months of stroke, ongoing oncological treatment, or hematologic cancer not in remission." Patients with ipsilateral carotid plaques to the ischemic stroke considered at high risk: thrombus on the wall, floating thrombus, ulcerated plaque.