Spontaneous Coronary Artery Dissection in Young Women Presenting with Acute Coronary Syndrome: Insights from the GENESIS-PRAXY Study - The 63rd Annual Conference of the Israel Heart Society in association with the Israel Society of Cardiothoracic Surgery 12-13 April 2016, David Intercontinental Hotel, Tel-Aviv, Israel

Avi Shimony ^1,2 Hatim Al Lawati ³ Akshay Bagai ³ Hassan Behlouli ⁵ Mark Eisenberg ⁵ Derek So ⁴ Igor Karp ⁵ Louise Pilote ⁵ Asim N. Cheema GENESIS PRAXY TEAM .

¹Cardiology, Jewish General Hospital, Montreal, QC
²Cardiology, Ben Gurion University, Soroka Medical Center, Beer-Sheva
³Cardiology, St. Michael's Hospital, Toronto, ON
⁴Ottawa Heart Institute, Ottawa Heart Institute, Ottawa, ON
⁵Clinical Epidemiology, McGill University Health Center, Montreal, QC

Background: Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome predominantly affecting younger women. However, limited information is available regarding its incidence, patients` profile, clinical course and outcome compared to younger women with acute coronary syndrome (ACS) not associated with SCAD.

Methods: Gender and Sex determinants of cardiovascular disease: From bench to beyond-Premature Acute Coronary Syndrome (GENESIS-PRAXY) study is multicenter prospective study of ACS patients aged 18 to 55 years. Detailed demographic, clinical, laboratory and outcome data were collected and coronary angiograms analyzed in a blinded manner.

Results: Of the 383 women enrolled, 36 patients (9.4 %) were diagnosed with SCAD. Multiple SCAD were reported for 8/36 patients. Compared to no-SCAD patients, SCAD subjects were more likely to have absence of any cardiac risk factor (19% vs 7%), lower LDL and higher HDL levels. SCAD patients were more likely to have single vessel disease (81 vs. 50%) with a lower SYNTAX score (8±6 vs. 12±8) compared to no-SCAD group. Revascularization (47% vs 72%) and final TIMI 3 flow (78% vs 93%) were less commonly achieved in SCAD compared to no-SCAD patients. The presence of autoimmune disease, connective tissue disorders were similar between the SCAD and no-SCAD group. Coronary hypertortuosity was identified more often in SCAD patients (90% vs. 10%). At 12 months, 31% of SCAD patients experienced a major adverse cardiac event (MACE) compared to 22% in no-SCAD group at 12 months (p=0.26).

Conclusion: SCAD is an important cause of ACS in younger women characterized by a low risk factor and angiographic burden of atherosclerosis, and coronary hypertortuosity. Nevertheless, one third of patients with SCAD experienced a MACE at one year. These findings underscore the need for greater understanding of SCAD mechanisms and better risk stratification for improving outcome in this high risk group.