Differences in Revascularization Strategy and Outcomes by Clinical Presentations in Spontaneous Coronary Artery Dissection

Background: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI). However, the role of revascularization for SCAD according to presentation remains unclear.Methods: We analyzed patients with SCAD who presented acutely and were participating in the Canadian SCAD Cohort Study. We compared revascularization strategy and clinical outcomes (in-hospital major adverse events and major adverse cardiovascular event [MACE] including recurrent MI at 1-year) in patients with SCAD presenting with ST-elevation MI (STEMI) vs unstable angina or non-STEMI (UA-NSTEMI).Results: Among 750 patients with SCAD (mean 51.7 +/- 10.5years; 88.5% were women; median follow-up was 373 days), 234 (31.2%) presented with STEMI. More patients with SCAD-STEMI (27.8%) were treated with revascularization (98.5% percutaneous coronary inter-vention [PCI]) compared with 8.7% of patients with UA-NSTEMI (93.3% PCI). For patients with SCAD and STEMI, 93.9% were planned pro-cedures vs 71.1% for UA-NSTEMI. Successful or partially successful PCI was 65.5% for STEMI and 76.9% for UA-NSTEMI (P < 0.001). In revascularized patients, 1-year MACE was not different between STEMI and UA-NSTEMI. Revascularization was associated with higher in -hospital major adverse events and its association was more promi-nent in UA-NSTEMI (STEMI: 26.2% vs 10.7%, P < 0.001; UA-NSTEMI: 37.8% vs 3.6%, P < 0.001). The difference in adverse events ac-cording to revascularization diminished over time and was not evident at 1 year.Conclusions: Despite higher in-hospital events with revascularization in patients with SCAD, and higher revascularization with SCAD-STEMI, 1-year MACE was not different compared with UA-NSTEMI. This is reassuring, as revascularization may be required for ongoing ischemia at the time of initial presentation in STEMI-SCAD, and emphasizes the need for careful patient selection for revascularization in UA-NSTEMI.