Abstract Body (Do not enter title and authors here): Background:
Spontaneous Coronary Artery Dissection (SCAD) is an rare but increasingly recognized cause of acute myocardial infarction (AMI) traditionally thought to predominantly affect young healthy women without typical cardiac risk factors. Recent studies suggest that SCAD may be underdiagnosed, particularly among underrepresented ethnic minority groups, and that its prevalence and clinical characteristics may vary across different populations. Furthermore, gender specific differences have not yet been well explored. Contemporary population-based studies on SCAD are lacking while comparing risk factors and trends to SCAD are not well explored.

Research question:
This study aims to elucidate the trends, incidence, and risk factors associated with SCAD compared to non-SCAD acute myocardial infarction (AMI) patients. We hypothesize that there are demographic and clinical differences between SCAD and non-SCAD AMI patients

Objectives:
To describe the incidence and trends of SCAD among AMI patients.
To identify and compare risk factors for SCAD versus non-SCAD AMI.
To analyze in-hospital outcomes associated with SCAD.

Methods:
We utilized data from the Nationwide Inpatient Sample (NIS) database from January 1, 2016, to December 31, 2019, identifying patients with AMI who underwent angiography. Patients were stratified into SCAD and non-SCAD AMI groups. Multivariable logistic regression was performed to identify risk factors associated with SCAD, and in-hospital outcomes were compared between the two groups.

Results:
Out of 1,912,780 AMI patients, 0.93% were identified with SCAD. Female SCAD patients had a median age of 57 years compared to 72 years for non-SCAD females. For males, the median age was 62 years for SCAD and 67 years for non-SCAD. Older age was associated with a lower risk of SCAD, while female sex and fibromuscular dysplasia (FMD) increased the risk. SCAD patients experienced higher in-hospital mortality (5.1% vs 3.5%), more post-procedural bleeding (8.0% vs 6.6%), and greater use of mechanical circulatory support (MCS) (13.9% vs 6.2%).

Conclusion:
SCAD patients show distinct age and gender-specific risk factors compared to non-SCAD AMI patients. SCAD is associated with higher in-hospital complications, including mortality and post-procedural bleeding. Understanding these differences is crucial for improving the diagnosis and management of SCAD in diverse patient populations.