Abstract 12535: Spontaneous Coronary Artery Dissection in Women: A New Role for Autoimmunity?

Introduction: Spontaneous coronary artery dissection (SCAD) is an uncommon cause of myocardial infarction (MI) in women, with a still unclear pathophysiology. Autoantibodies targeting angiotensin-II receptor type 1 (AT1R) and endothelin-1 receptor type A (ETAR) (AT1R-AAs and ETAR-AAs, respectively) lead to endothelial dysfunction and have already been associated with aortic dissection. Hypothesis: We hypothesized that titers of AT1R-AAs and ETAR-AAs are higher in patients with SCAD compared to controls. Methods: Our case-control study was conducted at Padua University Hospital between January 2022 and June 2022. Female patients diagnosed at coronary angiography with MI and SCAD were consecutively enrolled. Ten women with SCAD and 20 age-matched controls (10 women with ST-elevation MI (STEMI) and 10 healthy women) were included. Serum levels for AT1R-AAs and ETAR-AAs were determined for each participant. Absolute autoantibody titers and seropositivity prevalence were compared between SCAD patients, STEMI patients, and healthy women. Seropositivity was defined according to the threshold value suggested by the manufacturer (>10 U/mL). Results: Six out of 10 (60%) women with MI and SCAD were seropositive for AT1R-AAs and ETAR-AAs. In contrast, only one (10%) healthy woman and one (10%) STEMI patient were seropositive for AT1R-AAs (p=0.03 and p=0.03, respectively). One STEMI patient was seropositive for ETAR-AAs, while none of the healthy women was found to be seropositive (p=0.03 and p=0.01, respectively). The median autoantibody titer was significantly higher in SCAD patients than in healthy women (p=0.01 for AT1R-AAs; p=0.02 for ETAR-AAs) and STEMI patients (p<0.001 for AT1R-AAs; p=0.002 for ETAR-AAs). Conclusions: AT1R-AAs and ETAR-AAs seropositivity is significantly higher in SCAD women than in healthy women or female patients with STEMI. Our findings suggest a possible role for AT1R-AAs and ETAR-AAs in the pathophysiology of SCAD in women with MI.