An institutions experience in the utility of CCTA in the evaluation of post SCAD chest pain

Abstract Background Spontaneous coronary artery dissection (SCAD) is an uncommon cause of myocardial infarction and can be challenging to diagnose; treatment is often supportive. Post-SCAD chest pain (PSCP_ is common raises concern of extension or recurrence. Non-invasive imaging techniques are often preferred during re-evaluation given the risk of catheter-induced dissection. Coronary CT Angiogram (CCTA) is emerging modality for SCAD evaluation and has been recommended for use by consensus documents despite its limitation. . We review the utility of CCTA in evaluating our patients experiencing PSCP. Methods Patients enrolled in our SCAD registry (N=11) from 2019 to 2024 who experienced post-SCAD chest pain (N=5, 45%) that underwent CCTA (N=4) in our institution were included in series. All cases were female, presented with myocardial infarction and had single vessel SCAD diagnosed on invasive coronary angiogram. The cases this series had at least one subsequent emergency department visit for chest pain prior to CCTA without ECG changes or elevated cardiac biomarkers. No patients had any other CCTA for comparison imaging. Further baseline characteristics are outlined in table 1. Patients were imaged using the 384-detector Siemens Somatom Force dual-source CT system, a preliminary scout study was obtained, followed by coronary artery calcium protocol. Following administration of Omnipaque 350 intravenous contrast 0. 6 mm collimated images were obtained through the coronary arteries via Turboflash protocol. Data were transferred off-line for 3D reconstructions including curved MPR and multi-planar imaging. All patients were on regular betablockers and in sinus rhythm. Sublingual nitroglycerine was given just prior to scanning. Results All patients had a coronary artery calcium score of 0. Case 3 was reported to also have minimal diffuse disease in the right posterior descending artery on CCTA (non-culprit vessel) ; no other cases demonstrated evidence of CAD in any other coronary territory. CCTA findings were supportive both of the initial diagnosis of SCAD and absence of re-infarction or extension of SCAD in all of the cases. In keeping with previous reports and known limitations of CCTA distal-SCAD correlated to less specific findings on CCTA. "Time to CCTA" from index event varied greatly (49-293 days) and some patients may have demonstrated vessel healing resulting in the absence of more specific findings of SCAD. There were no repeat visits to the emergency department or hospitalizations for chest pain after CCTA was performed and resulted. There were no other pertinent clinical findings of CCTA imaging to account for chest pain in any of the cases. Conclusion PSCP remains a significant complication of SCAD and source of distress to affected individuals. CCTA can be a useful modality in ruling out re-infarction of extension of dissection, providing reassurance to patients on vessel healing and guiding clinical monitoring. Table 1