Review on Acute Aortic Dissection: Key Points
- Rylski B, Schilling O, Czerny M.
- Acute Aortic Dissection: Evidence, Uncertainties, and Future Therapies. Eur Heart J 2022;Dec 20:[Epub ahead of print].
The following are key points to remember from this state-of-the-art review on acute aortic dissection: evidence, uncertainties, and future therapies:
- Aortic dissection is an acute process in which a tear in the aortic intimal layer causes the intima and media to separate from the adventitia, resulting in the formation of an aortic false lumen in addition to the existing true lumen.
- The Stanford classification of aortic dissection uses “type A” for dissection involving the ascending aorta and “type B” for dissection involving only the descending aorta. This classification has been supplemented to include the designation “non-A non-B” if the dissection involves the aortic arch but not the ascending aorta.
- Complications of type A dissection include retrograde propagation often leading to prolapse of an aortic valve commissure with aortic regurgitation, coronary artery obstruction, and pericardial effusion. Complications of type B aortic dissection are defined as malperfusion of the spinal cord, gastrointestinal tract, kidneys, or extremities; pleural effusion containing blood; contained or free rupture; maximal aortic diameter >40 mm; or persistent pain.
- Treatment for all aortic dissections should include medical therapy. In the acute setting, intravenous beta-blocking agents should be used to reduce the heart rate and lower the systolic blood pressure to 100-120 mm Hg. In patients with chronic aortic dissection, blood pressure should be maintained below 140/90 mm Hg; along with lifestyle changes that include moderate physical activity, smoking cessation, and a healthy diet.
- Type A aortic dissection can be classified using a type, entry, malperfusion (TEM) system to help guide therapy. The type of aortic dissection is based on the supplemented Stanford classification (type A, type B, type non-A non-B). The primary entry tear location is designated as “0” (not visible), “1” (ascending aorta), “2” (arch), or “3” (descending aorta). Malperfusion status is designated as “0” (no malperfusion), “1” (coronary arterial), “2” (supra-aortic vessels), or “3” (visceral/renal or a lower extremity); a “+” sign is added if malperfusion is clinically evident or a “–“ sign is added if malperfusion is a radiological finding.
- Type A aortic dissection is managed with open surgery. Most patients with TEM type A E1 M0 benefit from ascending aorta replacement, whereas most patients with TEM type A E2 M3+ require aortic arch replacement with a hybrid frozen elephant trunk.
- Mortality risk in type A aortic dissection is variable. The 30-day mortality for patients who undergo surgery for type A dissection can be assessed using a scoring system that includes age, sex, resuscitation before surgery, previous cardiac surgery, intubation at referral, catecholamines at referral, aortic regurgitation, malperfusion status, neurological status, and dissection extent.
- Emergent aortic intervention is controversial but not recommended for all patients with type non-A non-B dissection. However, an entry point in the aortic lesser curvature is associated with a higher risk of retrograde propagation leading to type A dissection. Thoracic endovascular aortic repair (TEVAR) is associated with a substantial risk of retrograde type A dissection and should be avoided in patients with TEM non-A non-B E2 dissection.
- Many patients with type B dissection have been managed only medically. However, there are data that suggest that TEVAR might result in superior outcomes in terms of positive aortic remodeling compared to medical therapy alone. Risks for changing from an uncomplicated to complicated type B aortic dissection include proximal communication between lumens located at the lesser curvature or close to the subclavian artery, larger size of the proximal communication, descending aorta diameter >40 mm, or false lumen diameter >22 mm.
- An endovascular valve-carrying conduit (endo-Bentall) procedure has been described for use in the ascending aorta; however, the authors note that it has not been tested in a clinical setting owing to limited industry interest.
- Biomarkers could be of use to help accelerate the diagnosis of aortic dissection or as a prognostic marker among patients with chronic aortic dissection. In addition to cardiac troponin I and D-dimer, Aggrecan and an interleukin-1 receptor family member (ST2) have been tested in the diagnosis of acute aortic dissection.
Clinical Topics: Cardiac Surgery, Cardiovascular Care Team, Diabetes and Cardiometabolic Disease, Invasive Cardiovascular Angiography and Intervention, Pericardial Disease, Prevention, Valvular Heart Disease, Vascular Medicine, Aortic Surgery, Cardiac Surgery and Arrhythmias, Cardiac Surgery and VHD, Interventions and Structural Heart Disease, Interventions and Vascular Medicine, Diet, Exercise
Keywords: Aorta, Aneurysm, Dissecting, Aortic Valve Insufficiency, Biomarkers, Blood Pressure, Cardiac Surgical Procedures, Diet, Endovascular Procedures, Exercise, Healthy Lifestyle, Heart Valve Diseases, Pericardial Effusion, Pleural Effusion, Secondary Prevention, Troponin I, Vascular Diseases
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