ACR 2017 | Daily Highlights
Aortic Dilatation in Patients with Large Vessel Vasculitis: A Longitudinal Case Control Study Using Positron Emission Tomography/Computed Tomography
Authors: Filippo Crescentini1, Francesco Muratore2, Lucia Spaggiari3, Giulia Pazzola1, Luigi Boiardi1, Nicolò Pipitone1 and Carlo Salvarani4, 1Rheumatology Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Italy, 2Rheumatology Unit, Arcispedale Santa Maria Nuova - IRCCS; Università di Modena e Reggio Emilia, Reggio Emilia, Italy, 3Radiology Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Italy, 4Rheumatology Unit, Arcispedale Santa Maria Nuova - IRCCS; Università di Modena e Reggio Emilia, Reggio-Emilia, Italy
To evaluate aortic diameter and predictors of aortic dilatation using FDG-PET/CT in a longitudinally followed cohort of patients with large vessel vasculitis (LVV) compared with controls.
All consecutive patients with LVV who underwent at least 2 PET/CT scans between January 2008 and May 2015 were included. The first and last PET/CT study of each patient was independently evaluated by a radiologist and a nuclear medicine physician. The diameter of the aorta was measured at 3 different levels: ascending, descending thoracic and infrarenal aorta. Aortic dilation was defined as a diameter of >4 cm in the ascending, ?4 cm in the descending thoracic and ?3 cm in the infrarenal aorta. Aortic FDG uptake was graded at the same levels using a 0-3 semiquantitative scale and was reported as negative (score 0 or 1) or positive (score 2 and 3). Patients younger than 50 years at symptoms’ onset were classified as Takayasu arteritis (TAK), while those older than 50 years as giant cell arteritis (GCA). 29 age- and sex-matched patients with lymphoma who underwent at least 2 PET/CT in the same time interval without evidence of aortic FDG uptake were selected as controls.
93 patients with LVV were included in the study. 53% of patients were newly-diagnosed; the remaining 47% had a median disease duration of 34 months. At first PET/CT, the mean (SD) diameter of descending thoracic aorta was significantly higher in LVV patients compared with controls [28.07 (4.40) vs 25.60 (3.59) mm, p=0.012]. At last PET/CT, after a median time of 31 months, patients with LVV compared with controls had higher diameter of ascending [35.41 (5.54) vs 32.97 (4.11) mm, p=0.029] and descending thoracic aorta [28.42 (4.82) vs 25.72 (3.55) mm, p=0.007] and more frequently had aortic dilatation [19% vs 3%, p=0.023]. Significant predictors of aortic dilatation were male sex [OR 7.27, p=0.001], and the diameter of ascending [OR 2.03, p<0.001], descending thoracic [OR 1.57, p<0.001] and infrarenal [OR 1.25, p=0.005] aorta at first PET/CT study. Positive aortic FDG uptake, diasese activity and elevated inflammatory markers at first PET/CT were not associated with an increased risk of aortic dilatation. Results remained unchanged when the analysis were restricted to the 48 newly-diagnosed LVV patients.
According to age at symptoms onset, 56% of patients were classified as GCA and 44% as TAK. At first PET/CT, GCA compared with TAK patients had shorter disease duration, more frequent positive aortic FDG uptake and higher level of inflammatory markers. Compared with TAK, GCA patients had higher aortic diameter at all 3 levels evaluated in both first and last PET/CT study. However there were no differences in the proportion of patients with aortic dilatation (at last PET/CT 23% in GCA vs 15% in TAK, p=0.306). Results remained unchanged when the analysis were restricted to the newly-diagnosed patients.
Patients with large vessel vasculitis are at increased risk of aortic dilatation compared with age- and sex-matched controls. Significant predictors of aortic dilatation are male sex and aortic diameter at first imaging study. Positive aortic FDG uptake at first PET/CT is not associated with increased risk of aortic dilatation.
F. Crescentini, None; F. Muratore, None; L. Spaggiari, None; G. Pazzola, None; L. Boiardi, None; N. Pipitone, None; C. Salvarani, None.
To round up the imaging issues a study about development of aneurysms shall be summarized. 93 patients were studied using PET/CT. Almost 50% were newly diagnosed LVV, the findings were compared with PET/CT of patients with other diseases. Patients under 50 years of age were categorized as TAK, above 50 years of age as GCA. The authors state that a larger diameter of the Aorta at diagnosis as well as male sex were more frequently associated with aneurysm formation and that these parameters were more important than disease activity. An important weakness of the study is the lack of clinical data such as disease activity over time and medication. Nevertheless, the data are a good basis for larger prospective studies.
Um die Fragen der Bildgebung bei Grossgefässvaskulitis (LVV) abzurunden sei die Arbeit über die Entwicklung von Aneurysmen bei LVV erwähnt und zusammengefasst. Die Autoren haben 93 Patientinnen, von welchen gut die Hälfte eine neu-diagnostizierte Grossgefässvaskulitis hatten mittels PET/CT untersucht und mit Kontrollpatienten verglichen. Etwas vereinfachend haben sie alle Betroffenen unter 50 Jahren als TAK kategorisiert. Es werden bekannte Unterschieden zwischen TAK und GCA wie weniger ausgeprägte systemische Entzündung bei TAK und kürzere Krankheitsdauer bis Diagnosestellung bei GCA festgestellt. Bemerkenswert ist das Resultat, dass männliches Geschlecht und grösserer Diameter der Aorta bei Diagnosestellung eine grössere Bedeutung hinsichtlich Entwicklung eines Aneurysmas hatte als die Krankheitsaktivität bei Diagnosestellung. Leider fehlt in den Daten der Bezug zu klinischem Krankheitsverlauf und Medikation. Gleichwohl ist die Untersuchung eine gute Grundlage für die Beurteilung im klinischen Alltag und für die Planung weiterer Studien über Bildgebung.
Prof. Dr. Peter Villiger