Routine pre-operative echocardiography for detection of aortic stenosis?

I read the recent article by Loxdale et al. [1] with interest and commend them for their study into the use of pre-operative echocardiography to detect aortic stenosis (AS). I wish to raise some methodological points for discussion. Firstly, it is surprising that the authors considered aortic sclerosis and mild AS as a single condition. Aortic sclerosis implies that the valve is calcified (i.e. sclerotic) but not obstructing blood flow (i.e. not stenotic). International consensus guidelines distinguish aortic sclerosis as having a peak velocity of <2.5 m.s and mild AS as 2.5– 3.0 m.s [2]. Secondly, although the authors state that 31% of patients with aortic sclerosis or AS did not have an audible murmur, it should also be noted that 7 ⁄ 8 (88%) of patients with severe AS and 16 ⁄ 24 (67%) patients with moderate AS did have audible murmurs (total 23 ⁄ 32, 72%). Mild AS is not of haemodynamic concern and is unlikely to alter significantly the anaesthetic management of most patients. However, moderate or severe AS is functionally important and the majority of cases are detectable clinically; it is noted that only one patient with severe AS did not have an audible murmur. It is surprising that 1 ⁄ 3 patients with moderate AS apparently did not have an audible murmur. Only two of these had severe left ventricular impairment, suggesting that in the majority (with normal stroke volume), a murmur should have been audible. Finally, although their title mentions the ‘role’ of echocardiography, the authors do not discuss how their results should be integrated into clinical practice or, if inconclusive, how their results could inform the design of future studies to determine the role of echocardiography. Their findings do not support routine use of echocardiography in all such patients, especially as in many centres a dedicated daily service may not be feasible and surgery in this cohort should not be delayed. There remains a clear role for careful cardiac auscultation and examination and, whilst Loxdale et al. [1] should be congratulated for their efforts, their results do not imply that restricting echocardiography to those patients with audible murmurs is a practice that should be changed.