Author + information
- Victor Aboyans, MD, PhD∗ (, )
- Philippe Lacroix, MD,
- Najmeddine Echahidi, MD and
- Dania Mohty, MD, PhD
- ↵∗Department of Cardiology, Dupuytren University Hospital, 2 Martin Luther King Avenue, Limoges 87042, France
Violi et al. (1) are to be commended for their large study on the prevalence of subclinical peripheral artery disease (PAD) among patients with nonvalvular atrial fibrillation. Indeed, the ankle-brachial index (ABI) enables the detection of a substantial subset of individuals with asymptomatic (or with atypical symptoms of) PAD in diverse populations, and beyond its diagnostic interest, a low ABI is predictive for stroke, as highlighted recently in a meta-analysis (2). Violi et al. (1) reported an even higher than expected 21% prevalence of PAD detected by an ABI ≤0.90, almost doubling the proportion of patients with “vascular disease” as defined in the CHADS2-VASc (congestive heart failure [or left ventricular systolic dysfunction]; hypertension [blood pressure consistently >140/90 mm Hg or on hypertension medication]; age ≥75 years; diabetes mellitus; previous stroke, transient ischemic attack, or thromboembolism; vascular disease [e.g., peripheral artery disease, myocardial infarction, aortic plaque]; age 65 to 74 years; sex category [male or female]) score (i.e., myocardial infarction, complex aortic plaque, and PAD), advocated by the European Society of Cardiology guidelines on the management of atrial fibrillation, to assess the risk of stroke (3). However, we think that prior to proposing the measurement of ABI in patients with nonvalvular atrial fibrillation, several issues should be discussed.
First, the main interest of the CHADS2-VASc score is to determine whether oral anticoagulant therapy (OAC) is necessary. The European Society of Cardiology guidelines recommend OAC when CHADS2-VASc is ≥2 and prefer OAC to aspirin when the score is 1 (3). Hence, the practical interest of ABI measurement would be limited to those with a CHADS2-VASc score of 0 or 1 in order to detect “missed” cases of PAD, which would lead to increasing the score by 1 point and ultimately to revising the anticoagulation strategy. In their study, Violi et al. (1) report high rates of diabetes, hypertension, and history of myocardial infarction or stroke among those with an ABI ≤0.90. All those variables lead to a higher CHADS2-VASc score, so that the prevalence of ABI ≤0.90 among those with a current CHADS2-VASc score at 0 or 1 should be reported to clarify its incremental value to change anticoagulation strategy in these low-risk patients.
Second, 10% of the study population had an ABI >1.40, and these patients have apparently not been adequately taken into consideration, because almost one-half of these patients do have underlying PAD, although the definite diagnosis would need further tests as the ABI measurement is impeded by calcified arteries (4).
Finally, the accuracy of the ABI measurement in case of irregular rhythm is unknown. It has been shown that the measurement of arm blood pressure in this situation is associated with considerable intra- and interobserver variability, and it is plausible to wonder at similar poor results when making the ratio of pressures measured in several limbs (5). The only way to moderate the level of inaccuracy is to advocate systematically repeated measurements and to avoid taking the crucial decision of OAC on the basis of a sole measurement of the ABI.
Once these issues are addressed, we agree with Violi et al. that a prospective study is necessary to assess the ability of the ABI to reclassify low-risk patients and increase the CHADS2-VASc score discrimination index to predict stroke events in case of nonvalvular atrial fibrillation. Ultimately, a trial would be necessary to clarify the interest of OAC in patients with both low CHADS2-VASc score and ABI.
- American College of Cardiology Foundation
- Violi F.,
- Davi G.,
- Hiatt W.,
- et al.
- European Heart Rhythm Association,
- European Association for Cardio-Thoracic Surgery,
- Camm A.J.,
- et al.
- Aboyans V.,
- Criqui M.H.,
- Abraham P.,
- et al.
- Sykes D.,
- Dewar R.,
- Mohanaruban K.,
- et al.