Background and Purpose. We hypothesized that patients with persistent atrial fibrillation (AF) suffer from more severe cerebral infarction than patients with paroxysmal AF due to differences in clot structure and volume. Methods. This study includes consecutive patients with acute cerebral infarction and persistent or paroxysmal AF documented by ECG any time prior to stroke onset. The National Institute of Health Stroke Scale (NIHSS) was used to assess stroke severity on admission. Short-term outcome was determined by the modified Rankin scale (mRS) score, Barthel index, and NIHSS score 7 days after stroke onset. Risk factors were registered on admission. Eligible patients were treated with thrombolysis. Results. In total, 141 (52%) patients had paroxysmal AF, and 129 (48%) patients had persistent AF. NIHSS score on admission, mRS score at day 7, and mortality were significantly higher among patients with persistent AF. Thrombolysis was less effective in patients with persistent AF. Conclusions. Our study shows that patients with persistent AF and acute cerebral infarction have poorer short-term outcome than patients with paroxysmal AF. Differences in clot structure or clot volume may explain this. 1. Introduction Both persistent and paroxysmal atrial fibrillation (AF) are frequent causes of cerebral infarction. Risk of first-ever and recurrent cerebral infarction is thought to be similar in both persistent and paroxysmal AF [1–3]. Anticoagulation is the definite treatment of choice as to both primary and secondary preventive treatment in patients with AF [4]. Further, it has been shown that short-term outcome after cerebral infarction is better among patients on prior warfarin [5]. Atrial fibrillation causes cardiac embolism due to formation of thrombus in the left atrial auriculum [6, 7]. Thrombus formation is thought to be generated by stasis, endothelial dysfunction, and hypercoagulable state [8, 9]. The pathophysiology of thrombus formation may differ between patients with paroxysmal and persistent AF. One might speculate that shorter duration of AF in patients with paroxysmal AF is associated with smaller clots and clots more liable to early recanalization than in patients with persistent AF. Clots in persistent AF may be larger due to larger left atrial auriculum. Furthermore, clots in persistent AF may possibly be more organized and consolidated and therefore less prone to early recanalization. Studies on stroke patients rarely differentiate between patients with paroxysmal and persistent AF. We hypothesized that persistent AF is associated with
References
[1]
J. Manegold, et al., “Incidence of stroke in paroxysmal versus persistent/permanent atrial fibrillation and effects of oral anticoagulation or combined antiplatelet therapy: an ACTIVE W substudy,” European Heart Journal, vol. 27, Abstract 2711, 2006.
[2]
L. Friberg, N. Hammar, and M. Rosenqvist, “Stroke in paroxysmal atrial fibrillation: report from the stockholm cohort of atrial fibrillation,” European Heart Journal, vol. 31, no. 8, pp. 967–975, 2010.
[3]
S. H. Hohnloser, D. Pajitnev, J. Pogue et al., “Incidence of stroke in paroxysmal versus sustained atrial fibrillation in patients taking oral anticoagulation or combined antiplatelet therapy. An ACTIVE W Substudy,” Journal of the American College of Cardiology, vol. 50, no. 22, pp. 2156–2161, 2007.
[4]
R. Saxena and P. J. Koudstaal, “Anticoagulants for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischaemic attack,” Cochrane Database of Systematic Reviews, no. 2, article CD000185, 2004.
[5]
H. Naess, J. Brogger, U. Waje-Andreassen, T. T. Idicula, and L. Thomassen, “Preadmission use of warfarin improves short-term outcome in patients with acute cerebral infarction,” Cerebrovascular Diseases, vol. 28, no. 1, pp. 8–12, 2009.
[6]
N. M. Al-Saady, O. A. Obel, and A. J. Camm, “Left atrial appendage: structure, function, and role in thromboembolism,” Heart, vol. 82, no. 5, pp. 547–554, 1999.
[7]
A. L. Klein, R. A. Grimm, R. D. Murray et al., “Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation,” The New England Journal of Medicine, vol. 344, no. 19, pp. 1411–1420, 2001.
[8]
V. Fuster, L. E. Rydén, D. S. Cannom, et al., “ACC/AHA/ESC 2006 of the guidelines for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association task force on practice guidelines and the European Society of Cardiology Committee for practice guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society,” Circulation, vol. 114, no. 7, pp. 257–354, 2006.
[9]
T. Watson, E. Shantsila, and G. Y. Lip, “Mechanisms of thrombogenesis in atrial fibrillation: virchow's triad revisited,” The Lancet, vol. 373, no. 9658, pp. 155–166, 2009.
[10]
C. J. Johnson, S. J. Kittner, R. J. McCarter et al., “Interrater reliability of an etiologic classification of ischemic stroke,” Stroke, vol. 26, no. 1, pp. 46–51, 1995.
[11]
H. P. Adams Jr., B. H. Bendixen, L. J. Kappelle et al., “Classification of subtype of acute ischemic stroke: definitions for use in a multicenter clinical trial,” Stroke, vol. 24, no. 1, pp. 35–41, 1993.
[12]
J. Bamford, P. Sandercock, M. Dennis, J. Burn, and C. Warlow, “Classification and natural history of clinical identifiable subtypes of cerebral infarction,” The Lancet, vol. 337, no. 8756, pp. 1521–1526, 1991.
[13]
T. Wessels, et al., “Contribution of diffusion-weighted imaging in determination of stroke etiology,” American Journal of Neuroradiology, vol. 27, no. 1, pp. 35–39, 2006.
[14]
R. G. Hart, L. A. Pearce, R. M. Rothbart, J. H. McAnulty, R. W. Asinger, and J. L. Halperin, “Stroke with intermittent atrial fibrillation: incidence and predictors during aspirin therapy,” Journal of the American College of Cardiology, vol. 35, no. 1, pp. 183–187, 2000.
[15]
C. Marini, F. De Santis, S. Sacco et al., “Contribution of atrial fibrillation to incidence and outcome of ischemic stroke: results from a population-based study,” Stroke, vol. 36, no. 6, pp. 1115–1119, 2005.
