Author + information
- A. Ross Naylor, MD∗ ()
- ↵∗Vascular Research Group, Division of Cardiovascular Sciences, Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, United Kingdom
Shishehbor et al. (1) performed an analysis of outcomes after 3 strategies for treating cardiac surgery patients with concurrent carotid disease. They concluded (in a cohort of predominantly asymptomatic patients with unilateral carotid disease) that staged carotid artery stenting (CAS) and open-heart surgery (OHS) and combined carotid endarterectomy (CEA) and OHS have similar procedural risks but that outcomes favored staged CAS-OHS after the first year. In a subsequent interview, Dr. Shishehbor urged readers to “remember the whole point of doing this is to prevent stroke” (2). Shishehbor et al. (1) are absolutely correct in their statement, and it is therefore inexplicable that not once in the group's report did the investigators mention that there is a fourth treatment strategy, namely, to perform no prophylactic carotid intervention at all.
The Shishehbor et al. (1) study was based on 3 assumptions: first, that carotid disease is an important cause of stroke after coronary artery bypass grafting (CABG); second, that patients with asymptomatic carotid stenoses are at excess risk for stroke; and third, that prophylactic CEA or CAS can reduce this risk. Unfortunately, at least 2 of these assumptions do not stand up to scrutiny. First, 3 large natural-history studies (including 23,557 patients) showed that 95% of all post-CABG strokes cannot be attributed to carotid disease (3–5). Second, an extensive systematic review and meta-analysis showed that patients with unilateral, asymptomatic carotid stenoses face a very small risk for ipsilateral stroke (6). In addition, another systematic review showed that the risk for stroke ipsilateral to the nonoperated severe carotid stenosis in patients with bilateral severe carotid disease undergoing synchronous CEA plus CABG was extremely low (7). If carotid disease were responsible for a significant proportion of post-CABG strokes, the opposite should have been found.
The rationale underpinning prophylactic CEA or CAS is that it reduces the risk for stroke after CABG. The prevention of late stroke is not relevant to this debate. Accordingly, no one should criticize anyone offering synchronous CEA and CABG or staged CAS and CABG in patients reporting histories of transient ischemic attack or stroke. It has long been accepted that these patients really are at higher risk for post-CABG stroke. However, the evidence justifying prophylactic CEA or CAS before CABG in patients with unilateral, asymptomatic stenoses is tenuous, to say the very least. Accordingly, the statement in an accompanying editorial by Mahmud and Reeves (8) that this study “provides clarity for the management of patients with carotid and coronary disease” is not supported on the basis of currently available evidence. Moreover, the caveat that surgeons are loath to perform isolated CABG in this situation and that Shishehbor et al.'s (1) study represents “real-world practice” cannot be used to justify an uncritical policy of prophylactic carotid interventions with little or no supporting evidence.
- 2014 American College of Cardiology Foundation
- Shishehbor M.H.,
- Venkatachalam S.,
- Sun Z.,
- et al.
- ↵O’Riordan M. Stent first, then heart surgery, for patients with severe carotid/coronary disease. Heartwire. Available at: http://www.medscape.com/viewarticle/808862. Accessed January 29, 2014.
- Stamou S.C.,
- Hill P.C.,
- Dangas G.,
- et al.
- Mahmud E.,
- Reeves R.