Methods: Patients with SCAD on invasive coronary angiography who underwent a follow-up CTCA between 2010 and 2018 at our institute were included. CTCA was reported by two cardiologists-one with knowledge of the SCAD location, and a second blinded. Assessment of dissection healing were made and optimal timing of CTCA was also calculated.
Results: A total of 32 patients with 38 non-contiguous SCAD lesions were included (mean age 50.5 ± 8.8 years, 65.6% women). The left circumflex artery was the most commonly affected vessel (34.2%), and 71.1% of lesions occurred in distal or branch vessels. Median time that CTCA was performed was 40.5 days from the index event, and 25 of 38 lesions had healed (65.8%). On blinded reporting, the sensitivity and specificity of CTCA for assessment of dissection healing was 72% and 53.8%, respectively. The optimal timing of CTCA to assess healing was 80 days (AUC 0.774, p=0.006; sensitivity 76.9%, specificity 84.0%). When early CTCA was performed (<80 days), 21 of 24 lesions (87.5%) were unhealed, whereas late CTCA (≥80 days) showed healing in 10 of 14 lesions (71.4%).
Conclusion: The usefulness of CTCA in diagnosing SCAD remains challenging due to limitations in spatial and temporal resolution, particularly in distal vessels. The optimal timing of CTCA to assess dissection healing was 80 days.