Long-term follow-up of medically treated patients with spontaneous coronary artery dissection: a prospective, Swiss single-centre cohort study

AIMS OF THE STUDY
Spontaneous coronary artery dissection (SCAD) is an increasingly diagnosed cause of acute myocardial infarction. However, there is still a limited number of larger cohorts with long-term follow-up. We report on the largest Swiss single-centre cohort to date, with follow-up of up to 22 years.

METHODS
We prospectively collected SCAD cases from June 1998 until December 2020. A strategy of systematic follow-up angiography was applied. Information on long-term follow-up was collected up to the end of 2020. Major cardiovascular events (MACE) were defined as all-cause death, non-fatal MI, and non-fatal cardiac arrest.

RESULTS
We identified 105 SCAD patients (mean age 53 ± 11 years, 98 female, 5 peripartum). Presentation was myocardial infarction in all patients. In 102 patients, there was one contiguous dissection. Three patients had two (n = 2) or three (n = 1) non-contiguous dissections. In the majority of patients (n = 97), the primary treatment approach was conservative (dual antiplatelet therapy for 12 months in 90% of patients, statins in 91%). Seven patients were treated with percutaneous coronary intervention (PCI) and one patient underwent bypass surgery. Elective follow-up angiograms were performed in 73 asymptomatic patients after a median follow-up of 6.0 months (interquartile range [IQR] 5.5-6.5). These showed healing of the dissection (n = 65) or a good result after PCI (n = 5) in 70 patients. Three patients had a persistent dissection but conservative treatment was continued. After a median follow-up of 7.5 years (IQR 3.6-12.5) (longest follow-up: 22.5 years) there were 15 MACE. Five MACE occurred within 30 days of the index event: death following catastrophic peripartum left main SCAD (n = 1), out-of-hospital cardiac arrest with successful resuscitation 16 days after SCAD (n = 1), ST-segment elevation myocardial infarction due to occlusion of the dissected artery 10 hours after the index angiogram with subsequent PCI (n = 1), SCAD of a second vessel 8 days after the index SCAD (n = 1), and non-ST-segment elevation myocardial infarction with persistent, multisite SCAD 10 days after the index event (n = 1). There were 10 late MACE, including myocardial infarction and recurrent SCAD (different vessel/lesion) a median of 7.6 years (IQR 3.9-9.6) after the index event in eight patients and death with unclear cause in two patients.