Spontaneous Coronary Artery Dissection: Clinical Outcomes and Risk of Recurrence

Abstract

Background: Spontaneous coronary artery dissection (SCAD) is underdiagnosed and an important cause of myocardial infarction (MI), especially in young women. Long-term cardiovascular outcomes, including recurrent SCAD, are inadequately reported.

Objectives: This study sought to describe the acute and long-term cardiovascular outcomes and assess the predictors of recurrent SCAD.

Methods: Nonatherosclerotic SCAD patients were prospectively followed at Vancouver General Hospital systematically to ascertain baseline, predisposing and precipitating stressors, angiographic features, revascularization, use of medication, and in-hospital and long-term cardiovascular events. Clinical predictors for recurrent de novo SCAD were tested using univariate and multivariate Cox regression models.

Results: The authors prospectively followed 327 SCAD patients. Average age was 52.5 ± 9.6 years, and 90.5% were women (56.9% postmenopausal). All presented with MI; 25.7% had ST-segment elevation MI, 74.3% had non-ST-segment elevation MI, and 8.9% had ventricular tachycardia/ventricular fibrillation. Precipitating emotional stressors were reported in 48.3% and physical stressors in 28.1%. Fibromuscular dysplasia was present in 62.7%, connective tissue disorder in 4.9%, and systemic inflammatory disease in 11.9%. The majority (83.1%) were initially treated medically, with only 16.5% or 2.2% undergoing in-hospital percutaneous coronary intervention or coronary artery bypass graft surgery, respectively. The majority of SCAD patients were taking aspirin and beta-blocker therapy at discharge and at follow-up. Median hospital stay was 3.0 days, and the overall major adverse event rate was 7.3%. Median long-term follow-up was 3.1 years, and overall major adverse cardiac event rate was 19.9% (death rate: 1.2%; recurrent MI: 16.8%; stroke/transient ischemic attack: 1.2%; revascularization: 5.8%). Recurrent SCAD occurred in 10.4% of patients. In multivariate modeling, only hypertension increased (hazard ratio: 2.46; p = 0.011) and beta-blocker use diminished (hazard ratio: 0.36; p = 0.004) recurrent SCAD.

Conclusions: In our large prospectively followed SCAD cohort, long-term cardiovascular events were common. Hypertension increased the risk of recurrent SCAD, whereas beta-blocker therapy appeared to be protective.

Keywords: beta-blocker; coronary angiography; fibromuscular dysplasia; hypertension; myocardial infarction; women.