Author's reply

摘要

We thank Dr Theodoras Karapanayiotides and Dr Nikolaos Grigoriadis, and Dr Chris Imray and colleagues for their kind comments. Karapanayiotides and Grigoriadis question whether asymptomatic carotid stenosis is important in causing a substantial stroke burden. Epidemiological evidence shows that this is indeed the case. Many patients with asymptomatic carotid stenosis present with stroke, and have not hada previous transient ischaemic attack. Only a few have a transient ischaemic attack or amaurosis fugax before their stroke; therefore, confining treatment to symptomatic carotid stenosis would not prevent these strokes. However, despite the importance of population-based asymptomatic carotid stenosis, the absolute risk in individual patients is low. The investigators also question the practicality and reliability of monitoring for embolic signals in the clinical setting. Interobserver reproducibility studies between different centres in different countries have shown that high levels of agreement can be obtained.