Spontaneous Coronary Artery Dissection: Rediscovering an Old Cause of Myocardial Infarction

Spontaneous coronary artery dissection is an uncommon, but not insignificant cause of acute coronary syndrome that overwhelmingly affects middle-aged women. The pathophysiology of coronary dissection appears to be an outside-in mechanism, where the initiating event is not an intimal tear but rather the formation of an intramural hematoma, which compromises blood flow by reducing the arterial lumen. Considering this mechanism, it is clear to see how intracoronary imaging techniques, such as optical coherence tomography and intravascular ultrasound, are most accurate in the diagnosis. However, they carry a high rate of complications and are therefore generally avoided when the clinical scenario and angiographic appearance both support the diagnosis of spontaneous coronary artery dissection. The natural history of the disease is toward healing of the vessel wall and restoration of blood flow. Therefore, conservative medical management is the preferred approach unless there are high-risk factors such as hemodynamic instability, signs of ischemia and severe proximal or multivessel lesions, in which percutaneous or surgical revascularization should be considered. Perioperative evaluation of these patients must take into account several aspects of this disease. Most of these patients will be receiving single or dual antiplatelet therapy, so one must consider the timing of the event and the surgical hemorrhagic risk when deciding to stop these therapies. Extracoronary vascular disease also must be assessed because it can have an effect on patient monitoring and risk of postoperative complications.