Original Research Open Access Effect of stroke prevention medication on aortic atheroma progression assessed using new statistical paradigm Pratyaydipta Rudra 1 , Pranab K. Sen 1 , Lauren Dennis 2 and Souvik Sen 2* 1 Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina, USA. 2 Department of Neurology, University of South Carolina School of Medicine, Columbia, South Carolina, USA. *Correspondence: Souvik.Sen@uscmed.sc.edu Abstract Background: Progression of aortic arch atheroma (AA) is associated with vascular events in patients with stroke or transient ischemic attack (TIA). Studies investigating effect of stroke prevention medication on AA progression are limited to post-cerebral segments that may not be related to stroke pathophysiology and do not use information from the relevant segments adjacent to the origin of the cerebral blood vessels. Methods: AA atheroma was detected on baseline transesophageal echocardiogram (TEE) in 167 consecutive patients who had stroke or TIA. Of these, 125 consented to a follow-up TEE at12 months. Adequate paired AA images were obtained in 117 (78 with strokes, 39 with TIAs), which allowed detailed measurements of plaques. On admission for their index stroke or TIA, patients were assessed for stroke risk factors and stroke prevention medications (Statins, Antiplatelet therapy and oral anticoagulant). We assessed three segments of the AA adjacent to the origin of the cerebral blood vessels for plaque thickness by TEE and analyzed the effect of medication using joint modeling, with due consideration to confounding covariates. The statistical paradigm included a permutation testing procedure to determine the significance of medication effect on plaque progression in the three segments in combination. Results: Using the specified statistical paradigm, it is evident that statin therapy is effective in arresting the AA progression; however, there is no significant change induced by anticoagulant therapy. The cleaned data, after removal of influential observations, shows even more significance for the statin therapy. The constrained hypothesis tests in both cases show a smaller p-value suggesting that the statin therapy may be effective in arresting the AA progression. Conclusions: In this preliminary study of stroke/TIA patients with AA atheroma on transesophageal echocardiogram, AA atheroma progression was arrested by statin therapy, without any significant change induced by anticoagulant therapy. The statistical paradigm with due consideration of all segments implicated in stroke pathophysiology may be used to test the effect of other stroke prevention medications on AA progression. Keywords: Aorta, atherosclerosis, disease progression, echocardiography, stroke © 2016 Sen et al; licensee Herbert Publications Ltd. Tis is an Open Access article distributed under the terms of Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0). Tis permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction Significant aortic arch atheroma (AA) is the second most prevalent risk for cardioembolic stroke after atrial fibrillation, present in 16-20% of stroke/TIA patients [1,2]. It is a risk fac- tor for new and recurrent stroke [4] and has lack of definitive treatment effect [5]. Among patients with AA, a subgroup that underwent progression AA in the ascending and arch segments were found to be independently associated with recurrent vascular events [6]. Retrograde diastolic blood flow in the proximal descending aorta, which connects significant plaques thickness with brain-supplying arteries, has been iden- tified as a possible source of brain embolism [7]. In absence of Journal of Medical Statistics and Informatics ISSN 2053-7662 | Volume 4 | Article 4 CrossMark ← Click for updates