Total atherosclerotic burden by whole body magnetic resonance angiography predicts major adverse cardiovascular events - ScienceDirect

Atherosclerosis

Volume 228, Issue 1, May 2013, Pages 148-152

Atherosclerosis

https://doi.org/10.1016/j.atherosclerosis.2013.02.015 Get rights and content

Abstract

Objective

The purpose of the present study was to investigate the relationship between the Total Atherosclerotic Score (TAS), a measurement of the overall atherosclerotic burden of the arterial tree by whole body magnetic resonance angiography (WBMRA), and the risk of major adverse cardiovascular events (MACE), defined as cardiac death, myocardial infarction, stroke and/or coronary revascularization, assuming that TAS predicts MACE.

Methods and results

305 randomly selected 70 year-old subjects (47% women) underwent WBMRA. Their atherosclerotic burden was evaluated and TAS > 0, that is atherosclerotic changes, were found in 68% of subjects. During follow-up (mean 4.8 years), MACE occurred in 25 subjects (8.2%). Adjusting for multiple risk factors, TAS was associated with MACE (OR 8.86 for any degree of vessel lumen abnormality, 95%CI 1.14–69.11, p = 0.037). In addition, TAS improved discrimination and reclassification when added to the Framingham risk score (FRS), and ROC (Receiver Operator Curve) increased from 0.681 to 0.750 (p = 0.0421).

Conclusion

In a population-based sample of 70 year old men and women WBMRA, with TAS, predicted MACE independently of major cardiovascular risk factors.

Highlights

► Atherosclerosis was assessed with whole-body MRA in a population-based cohort. ► 4.8 years follow-up gave eight-fold risk of MACE if any atherosclerotic changes. ► Addition of the WBMRA-assessment to FRS improved classification for risk of MACE. ► Only one subject with normal arteries had an MACE indicating good test specificity.

Introduction

Identifying individuals with atherosclerosis in need of preventive treatment is an important task. Numerous tests and examinations [1], [2], [3], [4], [5] have been suggested to improve risk stratification as an addition to scoring systems, such as the Framingham Risk Score (FRS) [6].

The ultra-fast high-performance gradient system with the bolus chase method has enabled whole body magnetic resonance angiography (WBMRA), allowing visualization of the majority of the arterial tree by means of a single contrast-injection [7]. The method is continuously improving, but so far, the atherosclerotic burden and its relation to outcome have not been investigated [8], [9].

The Total Atherosclerotic Score (TAS), established with WBMRA, has been proposed to estimate systemic atherosclerosis [10].

The purpose of the present study was to investigate the relationship between TAS and the risk of major adverse cardiovascular events (MACE), assuming that TAS predicts MACE. Other markers of atherosclerosis (Ankle Brachial Index (ABI), Carotid Intima Media Thickness (CIMT), and evidence of plaques in the carotid arteries on ultrasound) were also evaluated for their ability to predict MACE.

Section snippets

Study population

After approvement by the Ethics Committee of the University of Uppsala, and written consent by the participants, WBMRA was performed on 306 subjects, aged 70, who were chosen consecutively from the population-based PIVUS (Prospective Investigation of the Vasculature in Uppsala Seniors) study [11]. They were thoroughly examined, as displayed in Table 1, and underwent the WBMRA within 3–22 months (mean 16 months) from study enrollment. 305 WBMRA-examinations were assessable: Previous studies have

Results

During follow-up, MACEs occurred in 25 of the 305 subjects (22 men and 3 women). Seven subjects suffered a stroke, 13 had an MI, and 16 underwent PCI or CABG (11 of these were also included in the MI-group). One participant died during PCI.

Discussion

TAS was a powerful predictor of MACE, with a more than eight-fold risk of developing MACE in subjects with any irregularity in the arteries on WBMRA. Thus, the degree of stenosis seems to be of minor importance in predicting MACE. Only one subject with normal arteries suffered an MACE during the follow-up suggesting good test specificity.

The golden standard of angiography is digital subtraction angiography (DSA) where ionizing radiation, as well as contrast agents, is used. WBMRA has not been

Limitations

The described population consisted of elderly Caucasians. The age being constant in the cohort eliminated a variable in the statistics but the results need to be confirmed in other populations as well.

Adding thigh compression might improve imaging, although vein overlapping was not a problem in this study. The limited resolution in the present study protocol might have caused errors in evaluation of the smaller arteries.

The time between obtaining the FRS-information and performing the WBMRA of

Conclusion

In conclusion, the atherosclerotic burden, evaluated with TAS on WBMRA, predicted MACE independently of major cardiovascular risk factors in a population-based sample of 70 year old men and women.

Sources of funding

This work was supported by the Swedish Research Council (grant no. K2010-64X-08268-23-3). Part of the PIVUS-study has been funded by an unrestricted grant from Astra Zeneca R&D.

Disclosures

L.J. is a part time employee at Astra Zeneca R&D, Mölndal, Sweden.

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