Decreased carotid artery flow and increased resistive index as potential causes of aortic sclerosis-related cognitive dysfunction
E Y Choi, M Kim, J W Lee, H Chung, K H ChunAbstract
Background
Aortic valve sclerosis (AVS) has been associated with a higher prevalence of cognitive dysfunction, regardless of the degree of stenosis. Although cerebral hypoperfusion is a potential mechanism, studies to reveal the detailed mechanisms have not been extensively conducted.
Methods
A total of 3,360 consecutive patients who underwent carotid ultrasound and transthoracic echocardiography at a tertiary cardiovascular hospital were analyzed, along with clinical data collection. The AVS was defined as thickened leaflets with increased echogenicity and a peak transaortic velocity < 2.5 cm/s. Follow-up data on new-onset cerebrovascular events were also collected.
Results
Patients with AVS had a higher prevalence of a history of ischemic stroke (14% vs. 2.4%, p<0.001) and atrial fibrillation (6.9% vs. 2.4%, p<0.001), a potential cause of embolic stroke. However, in patients without a previous history of stroke or atrial fibrillation, the presence of AVS was significantly associated with a higher prevalence (68.1% vs. 34.8%, p<0.001) and higher degree (r=0.339, p<0.001) of common carotid artery (CCA) plaques. The presence of AVS was also significantly associated with lower CCA-EDV (end-diastolic velocity), lower internal carotid artery-EDV, and higher resistive indices (Figure). The relationship between AVS and CCA-EDV remained significant even after adjusting for atherosclerotic risk factors, such as age, hypertension, diabetes, and smoking (β=-0.065, p=0.002). In patients without a previous stroke, the future ischemic stroke rate was not significantly different after 4.2 years (HR=1.22, 0.65-2.27, p=0.533).
Conclusion
In patients without a previous history of ischemic stroke, the presence of AVS was significantly and independently related to a higher degree of carotid atherosclerosis and cerebral hypoperfusion, suggesting a potential cause of cognitive dysfunction.