Patient selection and data collection
This study was performed at a single institution. There was no specific
funding provided for this study. This study was exempt from
Institutional Review Board approval under Category (4): Secondary
research for which consent is not required. We retrospectively compared
two groups of patients who had computed tomography angiograms (CTA) of
their thoracic aorta performed either at UMMC or a referral center prior
to transfer to UMMC. We first identified 71 patients treated for ATAAD
at UMMC between November 2015 and February 2020 who had thin-slice
(<2mm) electrocardiogram-gated CTAs of the thoracic aorta
available. To identify controls, we queried our imaging database for
thin-slice ECG-gated CTA of the thoracic aorta conducted for reasons
other than aortic pathology (such as evaluation of suspected pulmonary
embolism). Potential controls were identified (n =205). Propensity
score matching was conducted to determine the final study sample. The
propensity score was calculated with a logistic model including age,
sex, race, body surface area (at time of imaging), and hypertension and
matched using a caliper of 0.5 and exact matching on sex, race, and
hypertension. Body surface area was calculated using the Mosteller
Formula. After matching, 67 patients remained in each group with balance
on the factors in the model (Table 1).