Editor's Choice – Validation of the Management of Aortic Graft Infection Collaboration (MAGIC) Criteria for the Diagnosis of Vascular Graft/Endograft Infection: Results from the Prospective Vascular Graft Cohort Study

Abstract

WHAT THIS PAPER ADDSThe Management of Aortic Graft Infection Collaboration (MAGIC) criteria have been proposed as a novel diagnostic test for vascular graft/endograft infection (VGEI). The criteria were validated retrospectively in a prospective cohort of patients with definite and suspected vascular graft infections. For a definite VGEI diagnosis, the criteria had a good sensitivity but reduced specificity, owing to suspected VGEI. To improve the accuracy, further modifications of the criteria should be evaluated.Objective: The timely management of vascular graft/endograft infection (VGEI) is crucial to a favourable outcome, yet can be challenging as there is no validated gold standard diagnostic test. Recently, a new case definition has been proposed by the Management of Aortic Graft Infection Collaboration (MAGIC) to close the diagnostic gap. The aim of this study was to validate the MAGIC criteria as a suggested diagnostic standard for the diagnosis of suspected VGEI in the prospective Vascular Graft Cohort study (VASGRA). Methods: VASGRA is an open, prospective, observational cohort study. Prospective participants in VASGRA between 2013 and 2019 were included (257 patients; 137 with VGEI). The accuracy of the MAGIC criteria for a diagnosis of VGEI was evaluated retrospectively by calculating the sensitivity and specificity vs. the consensually adjudicated VASGRA infection status. Results: The VASGRA cohort categorised 137 (53.3%) patients as "diseased" and 120 patients as "not diseased"; using the MAGIC criteria, 183/257 (71.2%) patients were considered to be "diseased". Thus, for the MAGIC criteria, a sensitivity of 99% (95% confidence interval [CI] 96e100) and a specificity of 61% (95% CI 52e70) were calculated. Considering suspected VGEI according to the MAGIC criteria as "not diseased" achieved congruent assessments of the VASGRA team and the MAGIC criteria, with a sensitivity of 93% and a specificity of 93%. The accuracy of the MAGIC criteria for the different graft locations were also compared. If the suspected VGEIs were assigned to the "not diseased" group, VGEIs of the thoracic aorta seemed to have a poorer sensitivity (86%; 95% CI 73e95) than the other graft locations. Conclusion:The current MAGIC criteria offer good sensitivity and specificity in the context of true infections but a reduced specificity for a possible VGEI.

FDG PET/CT in abdominal aortic graft infection: A case report and literature review

“…Although there are no established gold-standard criteria for diagnosis of aortic graft infection (AGI), the Management of Aortic Graft Infection Collaboration (MAGIC) is a collective of clinicians who aim to construct a consistent diagnostic standard [15] . The guideline includes 3 categories, Clinical/Surgical, Radiological, and Laboratory, which are further divided into major and minor criteria.…”

“…Particularly, major CT criteria used alongside focal tracer uptake (versus diffuse uptake) can help determine the significance of inflammation and improve diagnostic accuracy [ 16 , 17 ]. FDG PET/CT uptake should be interpreted carefully however, as intensity of FDG uptake is unable to differentiate between infection and inflammation [ 6 , 15 , 18 ]. Moreover, some of the MAGIC minor radiologic criteria overlap with the natural inflammatory course following graft implantation and can make distinction from a subtle, chronic infection more ambiguous [15] .…”

“…FDG PET/CT uptake should be interpreted carefully however, as intensity of FDG uptake is unable to differentiate between infection and inflammation [ 6 , 15 , 18 ]. Moreover, some of the MAGIC minor radiologic criteria overlap with the natural inflammatory course following graft implantation and can make distinction from a subtle, chronic infection more ambiguous [15] . Because of this, there are recommendations to delay the use of FDG PET/CT imaging until 4-8 weeks after implantation to reduce false positives related to healing and inflammation [ 19 , 20 ].…”

Vascular graft infections

“…The non-specific Fitzgerald criteria [24] for abdominal or peripheral grafts or the modified Duke criteria [29] for composite grafts are also applied in this regard. To solve this problem, the Management of Aortic Graft Infection Collaboration (MAGIC) [30] suggested in 2016 a classification dividing clinical/surgical, radiological, and laboratory findings into major and minor criteria [Table 2], similar to the modified Duke criteria [29] in infective endocarditis. A suspected infection is defined as having one major criterion from any category or minor criteria from two of the three categories; confirmed infection requires one major criterion plus any other (major or minor) from another category.…”

“…Moreover, in low-grade infections, sensitivity descends to 55%, resulting in high false negatives [33] . Nevertheless, CTA can show perigraft fluid, gas [Figure 2], or other findings such as pseudoaneurysm or anastomotic leaks, included in the MAGIC criteria [30] . Due to the aforementioned facts, a second imaging modality is often required to support diagnosis, especially in cases where the infection is suspected [3,4] .…”