Natural History of Severe and Asymptomatic Carotid Lesions

Deciding whether to intervene a severe (70-80%) carotid lesion in an asymptomatic patient is challenging. We know the margin of error is small and an excess of events caused by the intervention could tilt the scales. However, the updated information on the natural evolution of these lesions is scarce.

This retrospective analysis included asymptomatic patients with severe lesions in the internal carotid artery as identified on an ultrasound between 2003 and 2018. After 5 years of follow-up, their rates of stroke/transient ischemic attacks were low, but their rates of lesion progression and mortality were high.

Doppler severity criteria for a 70-80% lesion was a peak systolic velocity >325 cm/s or an internal carotid/common carotid ratio >4, and an end diastolic velocity <140 cm/s.

Asymptomatic status was defined as no event within six months from the Doppler assessment.

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Primary outcomes were progression of stenosis to >80%, ipsilateral ischemic event without documented progression, and mortality.

About 182 patients met the inclusion criteria, with a mean patient age of 71.5 years

There was a 5.3% rate of stroke/transient ischemic attack during the 5-year follow-up. Strokes were not linked to lesion progression.

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Conversely, progression was high, since “only” 60.3% of patients had the same stenosis degree at the end of follow-up. All other patients showed progression.

Survival at the end of follow-up was 83.7%, which means this is a high-risk population. Risk factors associated with death were chronic renal insufficiency (hazard ratio [HR]: 9.67; 95% confidence interval [CI]: 2.05–45.6; p = 0.004), atrial fibrillation (HR: 7.55; 95% CI: 2.48–23; p < 0.001), prior neck radiation (HR: 6.37; 95% CI: 1.39–29.31; p = .017), and non-aspirin use at index Doppler (HR: 3.05; 95% CI: 1.12–8.33; p = .030).

Conclusion

Asymptomatic patients with 70-80% internal carotid artery lesions had low rates of ischemic events that were not associated with plaque progression. However, there was a high rate of progression, thus reinforcing the need to follow these patients closely.

Original Title: Natural History of Non-operative Management in Asymptomatic Patients with 70%-80% Internal Carotid Artery Stenosis by Duplex Criteria.

Reference: Thomas W. Cheng et al. Eur J Vasc Endovasc Surg, article in press. https://doi.org/10.1016/j.ejvs.2020.05.039.

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