Treatment pattern and outcome of spontaneous coronary artery dissection in Japan

Background: Characteristics, treatment pattern, and outcome of spontaneous coronary artery dissection (SCAD) have not been thoroughly investigated, especially in non-Western countries. Methods: Using a nationwide administrative database in Japan, we included all women hospitalized with a diagnosis of myocardial infarction (MI) who underwent coronary angiography between 2012 and 2017. Patients with SCAD were identified using the 10th revision of the International Classification of Diseases code. Patients who underwent iatrogenic procedure-related coronary dissection were excluded. Characteristics, treatment pattern, and in-hospital mortality were compared between SCAD and non-SCAD patients. For the analysis of in-hospital mortality, age-matched and propensity score matched pairs of cohort at a ratio of 1:1 were generated. Results: Of 68,909 women patients with MI, 322 (0.5%) had SCAD. Patients with SCAD were younger (mean ± SD: 52.8 ± 13.5 years vs. 75.2 ± 11.4 years, P < 0.001) and had lower burden of comorbidity than non-SCAD patients. Percutaneous coronary intervention (PCI) was less frequently performed in SCAD patients (54.3% vs. 84.0%, P < 0.001). Among SCAD patients treated with PCI, stenting was performed in 61.7% of patients. The in-hospital mortality was significantly lower in SCAD compared with non-SCAD (2.5% vs. 7.6%, P = 0.001), which was consistent in age-matched (2.5% vs. 7.5%, P = 0.001) and propensity score matched cohorts (2.6% vs. 6.5%, P = 0.033). Conclusions: In Japan, in-hospital mortality of SCAD patients was lower than non-SCAD patients, and comparable with other international studies. However, more than half of SCAD patients were managed with PCI; further investigation is required to clarify the optimal management for this condition.