SCAD comprises 2-4% of all cases of acute coronary syndrome.With typically elevated cardiac biomarkers and ECG changes, people will often undergo coronary angiography evaluation. It is important to recognize SCAD through angiography as other confirmatory measures carry increased risks. Angiography
There are 3 types of SCAD based on angiographic and anatomical criteria; with the designations based on the location and extent of the hematoma within the walls of the coronary arteries. Type 1 SCAD results from an intimal tear of the coronary artery (a tear of the innermost layer of the arterial wall) creating a false lumen as blood flows into the new space. A type 1 SCAD lesion is seen on angiography or intravascular imaging as a radiolucent flap separating the two flow channels; separating the false lumen from the true lumen of the coronary artery. Type 2 SCAD, the most common type of SCAD lesions, seen in 60-75% of patients, occurs due to an intramural hematoma or a collection of blood in the muscular layer of the coronary artery wall with the absence of intimal tearing. This is seen on coronary angiography as an abrupt change in coronary caliber with a long segment of a diffusely narrowed artery (typically longer than 20 mm). Type 2 SCAD is subdivided into type 2A where the narrowed segment of the coronary artery is flanked by normal caliber segments and type 2B where the stenosis continues to the terminus of a coronary artery.
Management
Management depends upon the presenting symptoms. In most people who are hemodynamically stable without high-risk coronary involvement, conservative medical management with blood pressure control is recommended. In these people, especially if angiography demonstrates adequate coronary flow, the most likely course usually leads to spontaneous healing, often within 30 days. Anti-coagulation should be discontinued upon diagnosis of SCAD on coronary angiography as continuation of anti-coagulation may lead to hematoma and dissection propagation.In cases involving high-risk coronaries, hemodynamic instability, or a lack of improvement or worsening after initial attempts at treatment, urgent treatment with coronary stents or coronary artery bypass surgery may be necessary. Stents carry the risk of worsening the dissection or have an increased risk of other complications as the vessel walls in SCAD are already weak due to the disease before introducing the stent. Large studies into coronary artery bypass surgery are lacking, but this approach is used to redirect blood to the heart around the affected area for cases involving the left main coronary artery or when other approaches fail.Angina, or chest pain due to coronary insufficiency may persist for months after SCAD, sometimes even when repeat angiography shows vessel healing. Anti-anginal agents such as nitrates, calcium channel blockers and ranolazine are indicated as anti-anginal pharmacologic agents after SCAD. Control of hypertension is also indicated after SCAD, with beta blockers especially showing a reduction in the recurrence of SCAD.