Study provides snapshot of spontaneous coronary artery dissection

MUNICH — Spontaneous coronary artery dissection primarily occurs in middle-aged women, with most acute presentations occurring at the same time as MI, according to new data from the Canadian Spontaneous Coronary Artery Dissection Cohort Study.

“Despite the first case report back in 1931, this condition remains underdiagnosed and poorly understood. Less than 1,300 cases have been published to date,” Jacqueline Saw, MD, clinical professor at Vancouver General Hospital, University of British Columbia, Canada, said during a presentation at the European Society of Cardiology Congress.

While recent advances in intracoronary imaging techniques have improved diagnosis of SCAD, further knowledge on the causes and natural history of SCAD is needed, Saw said.

Saw and colleagues examined the clinical presentation, natural history, treatment and outcomes of SCAD. The researchers prospectively enrolled 750 patients presenting acutely with SCAD at 20 centers in Canada and two centers in the United States from 2014 to 2018. Diagnosis of SCAD was adjudicated by an angiographic core laboratory. At baseline, information was collected on demographics, stressors and conditions that could have caused SCAD, and treatments, according to a press release. Follow-up was performed in the hospital and at 1, 6 and 12 months. Patients are being followed for 3 years for major adverse CV events.

Women comprised 88.5% of the overall SCAD cohort. Mean age at baseline was 52 years and 87% are white. One-third had hypertension, one-third reported migraines, 20% reported depression and 20% reported anxiety, Saw said during the presentation.

Regarding possible causes for SCAD, about half of patients (50%) reported emotional stress prior to the event, and 30% reported physical stress. In 10%, physical stress involved lifting more than 50 lb. The most common predisposing condition was fibromuscular dysplasia (31%), according to Saw.

“Emotional stress appears to be a major trigger for SCAD. Fibromuscular dysplasia, which is more common in women than men, also played a major role — it often has no symptoms, but in some patients it causes headaches or a swooshing sound in the ears called pulsatile tinnitus,” she said in the release.

Other predisposing conditions included five or more pregnancies (10%), active hormonal therapy (10%), systemic inflammatory disease (5%), peripartum state (4.5%) and connective tissue disorders (3.6%).

Saw noted that the majority of patients presented with an ACS: 70% with non-STEMI and 30% with STEMI. Only 0.4% presented with unstable angina. The predominant symptom upon presentation was chest pain in 91.5%. On angiography, the left anterior descending artery was most commonly affected (52%), and long diffuse narrowing, also known as type 2 SCAD, was the most common feature (60%), Saw said.

Most patients (85%) were treated with medication only, while 14% underwent PCI and less than 1% had CABG surgery.

Median hospital stay was 4 days. The overall rate of in-hospital major adverse events was 8.8%, which included death in 0.1%, congestive HF in 0.3%, stroke/transient ischemic attack in 0.8%, cardiogenic shock in 2%, unplanned revascularization in 2.5%, severe ventricular arrhythmia in 3.9% and recurrent MI in 4%.

Almost all patients (99%) survived to 30 days. Overall 30-day MACE included death (0.1%), congestive HF (0.4%), stroke/TIA (1.2%), unplanned revascularization (2.7%) and recurrent MI (6.1%). Other complications within 30 days included pericarditis (1.9%), new atrial fibrillation (0.9%), cardiac ED visit (4.9%) and admission for chest pain (2.5%).

In other findings, peripartum SCAD was an independent predictor of in-hospital major adverse events (OR = 2.8) and 30-day major adverse events (OR = 2.9), and connective tissue disorder was an independent predictor of in-hospital outcomes (OR = 8.7). Patients with peripartum SCAD had worse in-hospital major adverse events and in-hospital high-risk events (20.6% and 23.5%, respectively).

“SCAD predominantly affected young- to middle-aged women and presented with MI. Despite conservative therapy in the majority of patients, acute in-hospital and 30-day survival was good. However, significant CV complications occurred within 30 days post-SCAD, including recurrent MI, unplanned revascularization and stroke/TIA,” Saw said. “Longer-term follow-up of this large, prospective cohort and further investigations on pathophysiology, risk/predictors or recurrence and management are warranted.” – by Katie Kalvaitis

Reference:

Saw J, et al. Late Breaking Science in Interventional Cardiology 1. Presented at: European Society of Cardiology Congress; Aug. 25-29, 2018; Munich.

Disclosures: The study was funded by the Canadian Institutes of Health Research. Saw reports she received unrestricted research grant support from Abbott Vascular, AstraZeneca, Boston Scientific, Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, NIH, Servier, St. Jude Medical and University of British Columbia Division of Cardiology; speaker honoraria from AstraZeneca, Boston Scientific, St. Jude Medical and Sunovion; consultancy and advisory board honoraria from Abbott Vascular, AstraZeneca and St. Jude Medical; and proctorship honoraria from Boston Scientific and St. Jude Medical.