Several lines of evidence suggests that even in the absence of atrial fibrillation, patients with aortic stenosis (AS) may be at higher risk of a cerebrovascular accident (CVA).
A population-based study from Mayo Clinic examining the risk of cerebrovascular events (primarliy ischemic strokes or transient ischemic attacks) among patients with valvular heart disease reported severe aortic stenosis (study defined as mean pressure gradient >30 mm Hg) as a predictor of cerebrovascular event, independent from atrial fibrillation or age and at rates similar to those of mitral stenosis 1. Similarly, the simvastatin and ezetimibe in AS study involving patients with mild-to-moderate AS not prescribed oral anticoagulation found that CHA2DS2-VASc was a major predictor of stroke, independent of atrial fibrillation or aortic valve replacement2. Thromboembolic CVA has also been reported in the setting of calcified bicuspid aortic valve with moderate-severe AS3.
Potential factors increasing the risk of CVA in AS include calcium embolization from the valve and increased microthrombus formation on the valve which may be present in 53% of stenotic aortic valves3,4. In addition, severe AS may be a marker for other conditions that increase risk of CVA, such as atherosclerosis or prothrombotic tendencies1.
- Petty GW, Khandheria BK, Whisant JP. Predictors of cerebrovascular event and death among patients with valvular heart disease: A population-based study. Stroke 2000;31:2628-2635. http://stroke.ahajournals.org/content/strokeaha/31/11/2628.full.pdf
- Greve AM, Dalsgaard M, Bang CN, et al. Stroke in patients with aortic stenosis: The simvastatin and ezetimibe in aortic stenosis study. Stroke 2014;45:1939-1946. http://stroke.ahajournals.org/content/strokeaha/45/7/1939.full.pdf
- Mahajan N, Khetarpal V, Alfonso L. Stroke secondary to calcific bicuspid aortic valve: Case report and literature review. J Cardiol 2009;54:158-61. https://www.ncbi.nlm.nih.gov/pubmed/19632538
- Pleet AB, Massey EW, Vengrow ME. TIA, stroke, and the bicuspid aortic valve. Neurology 1981;31:1540-2. https://www.ncbi.nlm.nih.gov/pubmed/7198207