Largest-Ever SCAD Analysis Links Peripartum Status to Poor Outcomes

MUNICH, Germany—Women who present with a spontaneous coronary artery dissection (SCAD) before or shortly after giving birth fare much worse than women who develop SCAD during other times of their lives, a new analysis shows.

Women in the peripartum period presented with larger infarcts and worse LV function, more frequently had left main dissections, and had a higher rate of in-hospital major adverse events (20.6% vs 8.2%), Jacqueline Saw, MD (Vancouver General Hospital, Canada), reported here at the European Society of Cardiology Congress 2018.

In fact, after multivariable adjustment, peripartum status was the only factor independently associated with in-hospital major adverse events (OR 2.9; P = 0.02) and one of two associated with 30-day MACE (OR 2.8; P = 0.03). The other was connective tissue disorder (OR 8.7; P = 0.004).

Patrick Serruys, MD, PhD (Erasmus Medical Center, Rotterdam, the Netherlands), a panelist at Saw’s presentation, said he was impressed by the granularity of the analysis, which is the largest study of SCAD to date. He observed that most of the MACE in the overall cohort occurred in the first 15 days after discharge, and asked whether patients in the peripartum period or those with connective tissue disorder should be kept in the hospital for at least 15 days and potentially up to 30 days.

Patients with SCAD managed conservatively typically stay in the hospital for 4 to 5 days, Saw said, adding, however, that for higher-risk patients like those in the peripartum period, “we do advocate [staying] in the hospital for longer periods of time. It would be great to keep them for 15 days, although if the chest pain is settled typically by, say, 10 days, they can be discharged home.”

‘Underdiagnosed and Poorly Understood’

Even though SCAD was first reported in the medical literature in 1931, it “remains underdiagnosed and poorly understood,” Saw said, noting that information on fewer than 1,300 cases has been published. There are still many remaining questions dealing with predisposing and precipitating factors, management, and outcomes, she said.

To start filling in some of those gaps, Saw and colleagues initiated the Canadian SCAD Study, which prospectively enrolled 750 patients with new acute nonatherosclerotic SCAD at 20 centers in Canada and two in the United States. Consistent with prior studies, the vast majority of patients (88.5%) were women. Patient age in the overall cohort ranged from 24 to 89, with a mean of 52. One-third of patients had no cardiac risk factors, and 32% had hypertension. Migraines (32.5%), a history of depression (19.5%), and a history of anxiety (19.7%) were common.

Almost all patients presented with an acute MI—30% STEMI and 70% NSTEMI. Three had unstable angina. Chest discomfort was the main presenting symptom in 91.5% of the cohort.

When looking at precipitating stressors, half of the cohort had emotional stress that they rated as high or severe, and 28.9% reported unusually intense physical stress.

A predisposing condition was identified in half of the patients, with the most common being fibromuscular dysplasia (31.1%). Saw explained that that figure is lower than previously reported because 45.5% of patients either didn’t undergo screening or had incomplete screening for the condition.

Angiographic findings revealed that most patients (86.9%) had SCAD affecting a single vessel. SCAD was type 2 (long, diffuse narrowing) in 60.2%, type 1 (more than one lumen) in 29.0%, and type 3 (focal or tubular dissection) in 10.8%. Median diameter stenosis was 79%.

Management and Outcomes

The initial treatment approach was conservative for most patients (86.4%), although subsequent PCI was required in 2.0% and CABG in 0.3% of that group. PCI was the initial option in 11.9% of the cohort, with smaller numbers of patients being treated with fibrinolysis (1.5%) or CABG (0.3%)

PCI had varying success. Just 29.1% of procedures were deemed successful, 40.8% a partial success, and 30.1% unsuccessful.

The median hospital stay was 4 days. During hospitalization, 8.8% of patients had major adverse events. The most common were recurrent MI (4.0%), severe ventricular arrhythmia (3.9%), unplanned revascularization (2.5%), and cardiogenic shock (2.0%). There was one death.

About two-thirds of patients were discharged on dual antiplatelet therapy, and Saw said clopidogrel will typically be continued for at least a month until the patients can be seen again. Then, if the chest pain has been alleviated, clopidogrel will be discontinued.

In the 30 days after discharge, the rate of MACE (all-cause death, stroke, recurrent MI, congestive heart failure, or revascularization) was 8.8%; most of those events were recurrent MI (6.1%) and unplanned revascularization (2.7%).

Despite all the information gleaned from the cohort, Saw indicated that there are still many remaining questions. “Longer-term follow-up of this large prospective cohort is required, and further investigations on the pathophysiology, the risk and predictors of recurrence, and management are warranted,” she said.