Vascular Investigation and Therapy (Jan 2019)

Mortality risk stratification in patients with asymptomatic carotid stenosis

  • A Giannopoulos,
  • S Kakkos,
  • M B Griffin,
  • G Geroulakos,
  • D Tsalikakis,
  • Andrew Nicolaides

DOI
https://doi.org/10.4103/VIT.VIT_10_19
Journal volume & issue
Vol. 2, no. 2
pp. 25 – 32

Abstract

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AIMS: The aim of this analysis was to (a) determine the long-term 5-year all-cause and cardiovascular (CV) mortality in patients with asymptomatic internal carotid artery stenosis (ACS), (b) identify risk factors that could be used in mortality risk stratification, and (c) develop a model for predicting a patient's risk of CV death within 5 years. METHODS: This was a multicenter natural history study involving 1121 patients with ACS undergoing medical intervention alone. Proportional-hazards models were used to calculate all-cause and CV mortality using clinical and plaque texture features. RESULTS: Totally 1121 patients with 50%–99% ICA stenosis (European Carotid Surgery Trial criteria) from the Asymptomatic Carotid Stenosis and Risk of Stroke study were included in this analysis for mortality. Mean follow-up was 48 months (range, 6–96 months). There were 213 (19%) deaths during follow-up. Average annual all-cause mortality was 4.6%. About 68.1% of all deaths were due to CV causes. Independent predictors of all-cause mortality were age, male gender, carotid stenosis >80% (NASCET criteria), diabetes, cardiac failure, left ventricular hypertrophy (LVH) on electrocardiogram (ECG), smoking, absence of antiplatelet therapy, and history of vertebrobasilar symptoms. It was also shown that age, male gender, diabetes, fibrinogen >3.6 g/L, carotid stenosis >80% (NASCET criteria), cardiac failure, absence of antiplatelet therapy, and LVH on ECG were independent risk factors for CV mortality. Receiver operating characteristic curves for the above models were 0.709 (95% confidence interval [CI], 0.659–0.754) and 0.701 (95% CI, 0.656–0.746), respectively. The CV mortality prediction model could identify several subgroups of asymptomatic patients with different risk. The highest 90%–100% predicted 5-year CV mortality carried 25 times the risk of the low-risk subgroup in which the 5-year predicted CV mortality was 4%. CONCLUSION: Mortality risk can be taken into consideration in clinical practice, in order to identify patients with ACS who are unlikely to benefit from carotid endarterectomy. The majority of patients with ACS have a very high risk of myocardial infarction and should not be denied aggressive risk factor modification or a full cardiac investigation according to the current guidelines.

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