Background: Carotid bruits detected by simple auscultation have prognostic significance in type 2 diabetes but a trained operator is required. Electronic stethoscopes (ES) allow capture of carotid sounds by untrained staff with subsequent expert interpretation but their ability to identify clinically significant underlying carotid arterial disease is unknown.
Aim: To determine whether carotid bruits detected using an electronic stethoscope are associated with i) haemodynamically significant arterial stenoses and ii) increased carotid intima-medial thickness (IMT).
Patients and Methods: In an interim analysis of an ongoing study, ultrasonographic data from 34 patients with type 2 diabetes from the community-based Fremantle Diabetes Study Phase II (mean±SD age 73.6±9.8 years, 44.1% males, median diabetes duration 14.0 years) who had a carotid bruit identified on ES recordings by a study physician as part of detailed assessment and 16 (mean±SD age 71.5±8.4 years, 43.8% males, median diabetes duration 15.6 years) with normal carotid sounds were analysed. Carotid stenosis was assessed based on Doppler ultrasound. IMT was taken as the greatest thickness at any of three sites on either carotid artery. Comparison of proportions was by Fisher’s exact test.
Results: The data are summarised in the table:
|
Measure |
Patients with bruit |
Patients without bruit |
P-value |
|
Carotid stenosis >15% |
17 (50.0%) |
2 (12.5%) |
0.013 |
|
Carotid stenosis >50% |
10 (29.4%) |
0 (0%) |
0.020 |
|
IMT ≥1.0 mm |
21 (61.8%) |
1 (10.0%; n=10) |
0.009 |
Conclusions: These preliminary data suggest that an ES can identify patients with significant carotid arterial disease that should prompt i) intensification of cardiovascular risk factor management and ii) depending on symptoms, consideration of referral for imaging and possible revascularisation. This relatively inexpensive technology could have a place in the vascular assessment of patients in settings where carotid auscultation by a trained operator is unavailable.
This study is supported by an ADS Servier National Diabetes Strategy Grant in Memory of Barry Young.