The 15-year all-cause mortality rate is 10%.
Key clinical point: SCAD occurring during the peripartum period or in patients with connective tissue disease identifies subgroups at high risk for major adverse cardiovascular events within 30 days.
Major finding: Patients with spontaneous coronary artery dissection and comorbid connective tissue disease were at 8.7-fold increased risk of major adverse cardiovascular events within 30 days.
Study details: CanSCAD is an ongoing, prospective, multicenter, observational study in 750 patients with confirmed spontaneous coronary artery dissection.
Disclosures: CanSCAD is sponsored by the Canadian Institutes of Health Research, the Stroke Foundation of Canada, the National Institutes of Health, Abbott Vascular, Boston Scientific, AstraZeneca, and Servier.
MUNICH – The largest-ever study of spontaneous coronary artery dissection shows that, while most affected patients do well with conservative management, two independent risk factors identify subgroups at high risk for in-hospital and 30-day major adverse events.
Women whose spontaneous coronary artery dissection (SCAD) occurred during the peripartum period were at 2.8-fold increased risk of in-hospital major adverse events in a multivariate analysis, while those with a background connective tissue disorder were at 8.7-fold increased risk for major adverse cardiovascular events within 30 days of hospitalization in the Canadian SCAD (CanSCAD) study,, reported at the annual congress of the European Society of Cardiology.
CanSCAD is an ongoing, rigorous, prospective, multicenter, observational study of 750 patients with SCAD documented on angiography and confirmed in a core lab. To put the study in perspective, the worldwide medical literature published over the last decade contains fewer than 1,300 other cases of this seriously underdiagnosed, poorly understood disorder, noted Dr. Saw, CanSCAD principal investigator and a cardiologist at the University of British Columbia, Vancouver. Because much remains unclear about SCAD, a condition mistakenly considered to be rare in the past, the Canadian study was undertaken to shed light on predisposing and precipitating factors, optimal management, and clinical outcomes. Although Dr. Saw could present only the in-hospital and 30-day outcomes, follow-up will continue at 6, 12, 24, and 36 months.
SCAD is a nontraumatic, noniatrogenic, nonatherosclerotic separation of the coronary artery wall by intramural hematoma, creating a false lumen which compresses the true arterial lumen. This compromises blood flow with resultant myocardial ischemia or infarction. Intimal tear may or may not be present.
CanSCAD underscored that this is predominantly a disease affecting relatively young women: 89% of SCAD participants were female, 55% of whom were postmenopausal. The mean age at presentation was 52 years, and only 9% of subjects were older than age 65. Seventy percent of subjects presented with non–ST-elevation MI, the other 30% with STEMI. The predominant symptom was chest pain in 92% of patients. The average length of hospital stay was 4 days.
In terms of precipitating factors, half of patients cited high or severe emotional stress, with 41% of subjects scoring 20 or higher on the. About 30% of patients cited unusually intense physical stress, such as lifting more than 50 pounds, as a precipitating factor.
Of note, one-third of patients had no cardiovascular risk factors.
The in-hospital major adverse event rate – a composite of all-cause mortality, stroke, recurrent MI, cardiogenic shock, heart failure, cardiac arrest, repeat or unplanned revascularization, and heart transplantation – was 8.8%. Mortality through 1 month was reassuringly low, at 0.1%. Nonetheless, 4.9% of patients experienced recurrent symptoms necessitating emergency room visits within 30 days post discharge, and 2.5% required hospitalization because of their chest pain.
Patients who presented with SCAD during the peripartum period were more severely affected. Although they accounted for only 4.5% of subjects, their in-hospital major adverse event rate was 20.6%, compared with 8.2% in the others. They had a 17.6% prevalence of a left ventricular ejection fraction below 35%, as did only 3.1% of patients without peripartum SCAD. They were more than twice as likely to have elevated cardiac troponin levels. Moreover, peripartum SCAD was independently associated with a 2.9-fold increased risk of major adverse cardiovascular events at 30 days, a composite of all-cause mortality, stroke, recurrent MI, heart failure, or revascularization.
The other independent predictor of 30-day major adverse cardiovascular events in a multivariate logistic regression analysis was having a connective tissue disorder, present in 3.6% of participants.
Management was conservative, with no percutaneous coronary intervention used in 84% of patients. Outcomes were worse in the subgroup who underwent PCI, but Dr. Saw cautioned against making much of that.
“Keep in mind that the patients who undergo PCI are typically the higher-risk cohort with ongoing ischemia and chest pain, so there will be some bias there,” according to the cardiologist.
Session chair, of Erasmus University, Rotterdam, the Netherlands, commented, “It seems like there is a critical period of 30 days, more or less, and beyond that time the situation can be considered as settled and a wait-and-see attitude is fine. It looked like patients with peripartum dissection or connective tissue disease should potentially be kept in hospital for at least 15 days, and maybe 30 days, because I see your cumulative adverse event curve plateauing around 15 days.”
“Are you doing that in your practice?” asked Dr. Serruys.
“It’s true that conservatively managed patients should remain in hospital for typically about 4 days. For patients with a high-risk presentation we do advocate staying in hospital for longer periods,” Dr. Saw replied. “It would be great to keep them for 15 days, although typically if their chest pain has settled by 10 days they can be discharged home.”
Audience members were eager to hear her recommendations regarding dual-antiplatelet therapy. She explained that in her practice patients are generally discharged on aspirin and clopidogrel and typically continue the clopidogrel for at least a month.
“When we follow them in the office at 1 month, if their chest pain has settled, we would discontinue DAPT,” Dr. Saw said.
The ongoing CanSCAD study is sponsored by the Canadian Institutes of Health Research, the Stroke Foundation of Canada, the National Institutes of Health, Abbott Vascular, Boston Scientific, AstraZeneca, and Servier. Dr. Saw reported serving as a consultant to Abbott Vascular and Boston Scientific.
The 15-year all-cause mortality rate is 10%.