There is a debate on how to evaluate carotid artery intima-media thickness (IMT). We here compared IMT of the common carotid artery (CCA) and bulb with plaque area regarding incident atherosclerotic disease.
Ever since the introduction of carotid artery ultrasound in research of atherosclerosis, carotid artery intima-media thickness (IMT) has been evaluated. Since the ultrasound used in the clinic or in most epidemiological studies do not have the potential to differentiate the intima from the media layer, those two components of the vascular wall are lumped together into one measurement. IMT could be measured at multiple sites, near and far wall, in the common carotid artery (CCA), the bulb or the internal carotid branch, and with different angles. Furthermore, since atherosclerosis mainly originates in the bulb/proximal internal artery, it is possible to measure IMT-CCA without an involvement of a potential plaque or by including the plaque in the measurement. In addition, some investigators use the mean value of IMT at several sites, while many large population-based studies have only evaluated IMT in the far wall of CCA.
Materials and method
The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study started a random recruitment of men and women aged 70 years living in Uppsala City (Sweden) in 2001. Three years later 1,016 individuals (50% women) had been included. The participants were offered reinvestigations at age 75 and at age 80. 823 subjects attended the reinvestigation at age 75, and 604 at age 80.
As could be seen in Table 2, IMT-CCA was not significantly related to incident atherosclerotic disease, IMT-bulb was significantly related to incident atherosclerotic disease, but this relationship was attenuated following adjustment for cardiovascular disease (CVD) risk factors. Plaque area was related to incident atherosclerotic disease with a low p-value also following adjustment for CVD risk factors. Further addition of antihypertensive treatment, antidiabetic treatment, and statin use as confounders along with the CVD risk factors did not change the impact of the three indices of carotid atherosclerosis to any major degree compared to when adjustment for CVD risk factors were performed.
The present study showed that both plaque area and IMT-bulb were able to improve discrimination of future atherosclerotic events when added to traditional risk factors. This was not seen for IMT-CCA, despite that this commonly used measure did not actively avoid including plaques in the measurement.
The great work of Kerstin Marttala and Jan Hall for collecting the carotid artery measurements is highly appreciated.
Citation: Lind L (2023) A comparison of intima media thickness in the common carotid artery, the bulb and plaque area as predictions of incident atherosclerotic events. PLoS ONE 18(11): e0294722. https://doi.org/10.1371/journal.pone.0294722
Editor: Yasunori Sato, Keio University School of Medicine, JAPAN
Received: May 2, 2023; Accepted: November 6, 2023; Published: November 20, 2023
Copyright: © 2023 Lars Lind. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: Due to Swedish laws on personal integrity and health data, as well as the decision by the Ethics Committee, we are not allowed to make any data including health variables open to the public, even if made anonymous. The data could be shared with other researchers after a request to the Head of Department (email@example.com).
Funding: The PIVUS study was funded by Uppsala University Hospital (ALF-grants). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The author has declared that no competing interests exist.