Abstract WP130: Validation of Multi-parametric Ultrasonography Criteria with Catheter Angiography in Internal Carotid Artery Disease: A Prospective Multicenter Study

Introduction: Novel multi-parametric criteria for duplex ultrasonography (DUS) grading of extracranial internal carotid artery (ICA) steno-occlusive disease have been recently introduced by the German ultrasound expert panel (DEGUM). We sought to determine diagnostic accuracy of the DEGUM criteria against the gold standard catheter angiography. Methods: We prospectively enrolled consecutive patients who routinely underwent diagnostic or therapeutic catheter angiography of the extracranial carotid arteries at four German study sites. Internal carotid artery disease was graded according to the DEGUM multi-parametric criteria for DUS. On angiography, extracranial ICA disease was graded using the NASCET approach. Ultrasonography and endovascular raters were blinded to clinical data and any other imaging modalities. To correspond to clinically relevant NASCET groups, all stenosis measurements were stratified into ranges: normal, mild (1-49%), moderate (50-69%), severe (70-99%) and occlusion. Results: A total of 120 patients (median age, 69 [IQR, 16] years; 74% men; median time between DUS and angiography, 1 day [IQR, 2.5]) provided 162 DUS/angiography carotid artery pairs for final analysis. On angiography, moderate stenosis was found in 48 (30%) and severe stenosis in 63 (39%) arteries. Sensitivity of DUS for detection of moderate and severe stenosis was 35% (95%CI, 22-51%) and 81% (69-90%), with a NPV of 77% (68-84%) and 85% (75-92%), respectively. Specificity was 89% (81-94%) and 97% (94-99%), with a PPV of 57% (37-75%) and 62% (51-73%), respectively. Considering the entire spectrum of the disease (0-100%), the Bland-Altman interval limit of agreement was 51% (Figure). Conclusions: At laboratories experienced with ultrasound grading of the extracranial ICA, the novel DEGUM multi-parametric ultrasonography criteria do not eliminate the need for a confirmatory test for identification of clinically relevant grades of the disease.