Angiographic types of spontaneous coronary dissection and their impact on long-term outcome

Background Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of myocardial infarction (MI). However, it remains unclear whether and in which extent the different angiographic types of SCAD (type 1-3) impact patients´ outcome. Methods We analyzed data from all patients included in our national SCAD study. For this analysis, only patients with angiographically classified type of SCAD and complete follow-up were eligible. Patients with different types of SCAD during their index event were excluded. Cumulative rate of recurrent MI was the primary endpoint and assessed by Kaplan-Meier curves. Results Of 684 eligible patients, SCAD type 2 during index event was the most common diagnosis affecting 478 (69.8%) patients. SCAD type 1 was more common than SCAD type 3 (150 patients (22.0%) versus 56 patients (8.2%), respectively). Within the long-term follow-up of 1800 days, 57 patients (7.9%) had a recurrent MI of which 22 patients (38.6%) had recurrent SCAD. Assessment of cumulative rate of recurrent MI showed a significant gradient within 1800 days of long-term follow-up over the 3 predefined types of SCAD (p=0.04, Figure 1). Patients with type 1 SCAD during their index event had the highest rate of recurrent MI when compared to patients with type 2 and type 3 SCAD (12.0% versus 6.7% versus 5.3%, respectively). There was a statistically significant difference when comparing the cumulative rate of recurrent MI in patients with type 1 and type 2 SCAD during 1800 days of follow-up (p=0.01). Conclusion The angiographic type of SCAD had a significant impact on the cumulative rate of recurrent MI during long-term follow-up. Patients with initial type 1 SCAD had the highest event rate when compared to patients with type 2 and 3 SCAD.