Tobias Saam MD, Presenter: Research Grant, Diamed Medizintechnik GmbH Research Grant, Bayer AG

Anna Bayer-Karpinska, Abstract Co-Author: Nothing to Disclose

Tobias Boeckh-Behrens, Abstract Co-Author: Nothing to Disclose

Andreas Schindler MD, Abstract Co-Author: Nothing to Disclose

Andreas Dietrich Helck MD, Abstract Co-Author: Nothing to Disclose

Holger Poppert, Abstract Co-Author: Nothing to Disclose

Florian Schwarz MD, Abstract Co-Author: Nothing to Disclose

Dirk-Andre Clevert MD, Abstract Co-Author: Speaker, Siemens AG Speaker, General Electric Company Speaker, Toshiba Corporation Speaker, Koninklijke Philips NV Speaker, Bracco Group

Konstantin Nikolaou MD, Abstract Co-Author: Speakers Bureau, Siemens AG Speakers Bureau, Bracco Group Speakers Bureau, Bayer AG

Frank Wollenweber, Abstract Co-Author: Nothing to Disclose

Martin Dichgans MD, Abstract Co-Author: Nothing to Disclose

In up to 40% of patients with ischemic stroke no definite etiology can be established. A significant proportion of these cryptogenic stroke cases may be due to non-stenosing atherosclerotic plaques or low grade cervical artery stenosis not fulfilling common criteria for atherothrombotic stroke. The purpose of the Capias trial  is to determine the frequency, characteristics and clinical long-term consequences of ipsilateral complicated American Heart Association lesion type VI (AHA-LT6) carotid artery plaques in patients with cryptogenic stroke compared to patients with defined stroke etiology.

300 patients (age >49 years) with unilateral DWI-positive lesions in the anterior circulation and non- or moderately stenosing ( < 70% NASCET) internal carotid artery plaques will be enrolled in the prospective multicenter study Capias. Carotid plaque characteristics will be determined by high-resolution black-blood carotid MRI at baseline and 12 month follow up.

The study started on February 15th 2011. So far, clinical and radiological baseline data of 115 patients have been analyzed. Table 1 demonstrates the baseline characteristics and the prevalence of AHA-LT6 in each stroke subtyping using the TOAST criteria. An initial analysis of primary endpoint data showed a significantly higher prevalence of complicated AHA-LT6 plaques in cryptogenic stroke patients ipsilateral (32%) than contralateral (5%) to the ischemic stroke (p < 0.001, McNemar). 3-month follow-up data was available in 101 patients and 5 cerebrovascular events (1 TIA, 4 strokes) occurred. 4 out of 5 events (80%) occurred in patients with AHA-LT6 plaques.

Baseline data of the Capias trial suggests that arterio-arterial embolism from non-stenotic carotid atherosclerotic plaques play a role in the pathogenesis in a subset of subjects previously diagnosed with a cryptogenic stroke. The majority of recurrent strokes occurred in patients with AHA-LT6, suggesting that AHA-LT6 could be an important imaging biomarker to assess risk of stroke recurrence.

Depending on the results of CAPIAS, this study may have important implications for diagnostic decision making and provide the basis for the planning of targeted interventional studies.

Saam, T, Bayer-Karpinska, A, Boeckh-Behrens, T, Schindler, A, Helck, A, Poppert, H, Schwarz, F, Clevert, D, Nikolaou, K, Wollenweber, F, Dichgans, M, The Carotid Plaque Imaging in Acute Stroke (Capias) Study: Baseline and 3-month Follow-up Data.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006001.html