Spontaneous Coronary Artery Dissection: Clinical Outcomes and Risk of Recurrence

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.

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

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.

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.

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.