(VP068) INTRACORONARY IMAGING IN SPONTANEOUS CORONARY ARTERY DISSECTION (SCAD)

Background: Spontaneous coronary artery dissection (SCAD) is an increasingly recognised cause of acute myocardial infarction, especially in young women without conventional cardiac risk factors. The role of intracoronary imaging in the assessment algorithm for SCAD is yet to be clearly defined, with a paucity of data on safety of use in this condition.

METHODS AND RESULTS: We analyzed baseline demographics, clinical presentation and cardiovascular outcomes of patients in the Canadian SCAD Cohort Study and NACAD registry who underwent intracoronary imaging with optical coherence tomography (OCT) or intravascular ultrasound (IVUS) to aid the diagnosis of SCAD. Coronary angiograms and intracoronary imaging were reviewed by 2 experienced interventional cardiologists.

Of 1,306 patients in our SCAD cohort, 70 underwent OCT (72.8%) or IVUS (27.2%) at acute presentation. Mean age was 48±10.5yrs, 80% were women and 45.7% had confirmed fibromuscular dysplasia (FMD). All patients presented with acute coronary syndrome; 60% non-ST-elevation, 40% ST-elevation, and the LAD was most frequently involved (70%). [Table 1] Angiographic SCAD Type was 1 in 16 (22.9%), and of these 4 (25%) involved >1 vessel. Type 2 SCAD was present in 61.3% and Type 3 in 15.7%. The median (IQR) angiographic stenosis severity was 66.0% (55.2, 95.7) and length 37.5mm (23.9, 63.6). Baseline TIMI flow was 3 in 67.1%, 2 in 8.6%, 1 in 15.7% and 0 in 8.6%. Complications with the use of intravascular imaging occurred in 6 (8.6%) cases; ST-elevation and chest pain during IVUS (n=2), propagation of dissection following OCT (n=2), propagation of dissection after wiring (n=1) and iatrogenic catheter-induced dissection prior to wiring (n=1). [Table 2] Where intravascular imaging was associated with complications, 5 of 6 (83%) patients required unplanned revascularisation with PCI. The majority of the cohort were managed conservatively throughout their hospital stay (65.7%). The remainder underwent revascularisation, with either PCI (32.9%) or CABG (1.4%). Other in-hospital complications included recurrent MI (5.7%), cardiac arrest (4.3%) and stroke (1.4%). During a median follow-up of 4.0 (3.0, 6.2) yrs, recurrent MI occurred in 8 (11.4%), repeat revascularisation in 3 (4.3%) and 1 patient (1.4%) died.

Conclusion: Intracoronary imaging is useful in the diagnosis of SCAD but can be associated with complications. OCT/IVUS should be performed carefully and in select cases only when SCAD diagnosis is uncertain.