Improving selection of patients with less than 60% asymptomatic internal carotid artery stenosis for follow-up carotid artery duplex scanning

M. R. Nehler, G. L. Moneta, R. W. Lee, J. M. Edwards, Jr Taylor, J. M. Porter, R. E. Zierler, J. Goldstone, A. D. Whittemore, Jr Strandness, Y. N. Hsiang

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Purpose: The Asymptomatic Carotid Atherosclerosis Study (ACAS) indicated significant benefit from endarterectomy compared with medical therapy for patients with 60% to 99% asymptomatic internal carotid artery (ICA) stenoses. To date, optimal selection of patients for vascular laboratory follow-up to determine progression from <60% to >60% asymptomatic ICA stenosis is unknown. To determine which patients with <60% asymptomatic ICA stenoses are at greatest risk for short-term progression to ≤60% without symptoms, we reviewed vascular laboratory results and clinical risk factors of consecutive patients who were prospectively observed in a study of atherosclerosis progression. Methods: Carotid duplex studies were obtained every 6 months and were reviewed for progression from <60% to ≤60% asymptomatic ICA stenosis by using criteria that were developed and reported by our laboratory. Clinical risk factors and velocities from initial duplex scans were analyzed for association with progression from <60% to ≤60% ICA stenoses without symptoms. Results: Two hundred sixty-three patients (mean age, 66 years) with 434 asymptomatic <60% ICA stenoses were prospectively observed for a mean of 20 months, with a mean of four examinations per patient. Seventeen patients (6.5%) and 18 ICAs (4%) progressed without symptoms to ≤60% ICA stenoses at a mean of 18 months. Clinical risk factors associated with progression to ≤60% asymptomatic ICA stenosis included elevated systolic blood pressure and decreased ankle-brachial index (p = 0.05). The mean initial ICA peak systolic velocity (PSV) in ICAs that progressed to ≤60% asymptomatic stenoses was 180 cm/sec, compared with 104 cm/sec in asymptomatic ICAs that did not progress to ≤60% (p = 0.0003). Thirty-one percent of asymptomatic ICAs that had initial PSVs of 175 cm/sec or greater progressed to ≤60% stenosis, whereas only 1.8% that had initial PSVs less than 175 cm/sec progressed to ≤60% asymptomatic stenoses (p < 0.001). The life-table-determined rate of freedom from progression to ≤60% stenosis was 94% at 4 years for asymptomatic ICA lesions that had initial PSVs less than 175 cm/sec, compared with 14% at 3 years for lesions that had initial PSVs >175 cm/sec. Conclusions: Early progression from <60% asymptomatic ICA stenoses to ≤60% asymptomatic ICA stenoses occurs infrequently. Patients who are at the greatest risk of early progression without symptoms to an ACAS-positive lesion can be identified from the ICA PSV at their initial duplex examination. Early vascular laboratory follow-up of asymptomatic ICA stenoses may be limited to a relatively small group.

Original languageEnglish (US)
Pages (from-to)580-587
Number of pages8
JournalJournal of vascular surgery
Volume24
Issue number4
DOIs
StatePublished - 1996

ASJC Scopus subject areas

  • Surgery
  • Cardiology and Cardiovascular Medicine

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