Antithrombotic strategies in conservatively managed patients with spontaneous coronary artery dissection

Background There is a lack of randomized data to guide clinical practice regarding the prescription of single versus dual antiplatelet therapy in patients with Spontaneous Coronary Artery Dissection (SCAD) who are managed conservatively. Methods We analyzed and compared cardiovascular outcomes of patients with SCAD who were conservatively managed throughout their index hospitalization and discharged on either single (SAPT) or dual (DAPT) antiplatelet therapy. We excluded patients who were revascularized during the initial angiogram (n=93) or after a recurrent event in-hospital (n=17), died prior to discharge (n=1), or who did not receive antiplatelet therapy (n=29), including those with an indication for oral anticoagulation (n=28). We assessed 1yr major adverse cardiovascular events (MACE), which included death, recurrent myocardial infarction (MI), unplanned revascularization, stroke/transient ischemic attack (TIA), and congestive heart failure (CHF). Results Of 750 prospective patients, 582 received either SAPT (40.4%) or DAPT (59.6%) at discharge. Mean age was 51.7 years and 88.8% were women. The presentation was ST-elevation MI in 26.3% and NSTEMI in 73.7% of cases. Angiographic SCAD type was Type 1 in 32%, Type 2A in 40%, Type 2B in 29% and Type 3 in 13%. Baseline demographics and angiographic characteristics were similar between groups. The proportion of patients receiving DAPT decreased over time, as expected; 45.8% at 6 months, 23.7% at 1yr and 6.2% at 2yrs post-discharge. The cumulative rate of MACE in the cohort was low (3.4% with SAPT vs 4.6% with DAPT at 1-year) (Figure 1). There were also no significant differences between antiplatelet groups either at 1-month or 1-year post-discharge (p=0.530 and p=0.530, respectively). Similarly, rates of unplanned revascularization, stroke and CHF were low at 1-year and similar between groups (p=1.0, p=1.0 and p=0.163, respectively). Conclusions In a large cohort of prospectively enrolled patients with SCAD who were treated conservatively throughout their hospitalization, we found no significant difference with regard to outcomes at 12-months in those prescribed either SAPT or DAPT at discharge.