Acute type A aortic dissection — case discussion

Step 1 — Presentation and risk

Scenario (practice case, not a real patient): A 52-year-old man with treated hypertension and known aortic valve disease presents with sudden, severe chest pain radiating to the back. Blood pressure (BP) is 154/72 mmHg in the right arm and 118/64 mmHg in the left arm, heart rate 98 beats/min. He has no new murmur, no hypotension and no focal neurological deficit.^[1]

Discussion:

• His aortic dissection detection-risk score (ADD-RS) in European Society of Cardiology (ESC) 2024 Figure 30 is 3: a high-risk condition (known aortic valve disease), a high-risk pain feature (abrupt onset, severe intensity) and a high-risk examination feature (a perfusion deficit with differential systolic blood pressure).^[1]
• An ADD-RS of 2 or more is high risk: cardiovascular computed tomography (CCT) from neck to pelvis without delay and/or focused transthoracic echocardiography (TTE) plus an electrocardiogram (ECG).^[1]
• American College of Cardiology/American Heart Association (ACC/AHA) 2022 lists asymmetric BP of more than 20 mm Hg between limbs, from compromise of branch artery flow, among the signs of acute aortic syndrome (AAS).^[2]

Step 2 — Imaging

Result: ECG-gated CCT from neck to pelvis shows an intimal flap arising in the ascending aorta and extending through the arch into the descending thoracic aorta. Focused TTE shows a small pericardial effusion.^[2][1]

Discussion:

• Involvement of the ascending aorta makes this Stanford type A; a tear originating in the ascending aorta and propagating to the arch and descending aorta is DeBakey type I (ACC/AHA 2022).^[2]
• ECG-gated CCT from neck to pelvis is the ESC 2024 first-line imaging technique in suspected AAS (Class I, Level C), and focused TTE (with contrast if feasible) is recommended during the initial evaluation (Class I, Level C).^[1]
• Pericardial effusion is among the clinical features ESC 2024 describes as specific to acute type A dissection.^[1]

Step 3 — Medical stabilisation

Discussion:

• ESC 2024 recommends immediate anti-impulse treatment targeting systolic BP (SBP) below 120 mmHg and heart rate 60 beats per minute (b.p.m.) or less, with a higher mean arterial pressure maintained in spinal ischaemia or concomitant brain injury (Class I, Level B).^[1]
• ESC 2024 also recommends intravenous beta-blockers (e.g. labetalol or esmolol) as first-line agents, with intravenous vasodilators (e.g. dihydropyridine calcium blockers or nitrates) that could be added if necessary (Class I, Level B); invasive monitoring with an arterial line and continuous three-lead ECG recording, and admission to an intensive care unit (Class I, Level B); and adequate pain control to achieve haemodynamic targets (Class I, Level C).^[1]
• ACC/AHA 2022 says patients with AAS should be treated to an SBP below 120 mm Hg or the lowest BP that maintains adequate end-organ perfusion, and to a target heart rate of 60 to 80 bpm (b.p.m.) (class of recommendation [COR] 1, level of evidence [LOE] C-LD).^[2]
• Before starting, check for beta-blocker contraindications (e.g. acute aortic regurgitation, heart block or bradycardia), which ACC/AHA 2022 says call for caution.^[2]
• Drug doses: per local formulary and specialist guidance.

Step 4 — Definitive management

Discussion:

• ESC 2024 recommends emergency surgical consultation and evaluation and immediate surgical intervention in acute type A dissection (Class I, Level B); ACC/AHA 2022 makes the same recommendation for suspected or confirmed acute type A dissection (COR 1, LOE B-NR).^[1][2]
• If the local centre is low volume, ESC 2024 says transfer to a high-volume aortic centre with a multidisciplinary team should be considered to improve survival if it can be accomplished without significant delay in surgery (Class IIa, Level B).^[1]
• ESC 2024 describes a mortality of about 50%, at 1%–2% per hour, within the first 48 h if acute type A dissection is managed medically only.^[1]
• For potential cardiac arrest from pericardial tamponade, ESC 2024 advises considering an emergency pericardial puncture as a temporary life-saving measure before transfer to the operating room.^[1]
• At operation: if the root is partially dissected but the aortic valve leaflets have no significant pathology, aortic valve resuspension is recommended over replacement (ESC 2024 Class I, Level B); if there is extensive root destruction, a root aneurysm or a known genetic aortic disorder, root replacement with a mechanical or biological valved conduit is recommended (Class I, Level B).^[1]
• An open distal anastomosis is recommended to improve survival and increase false-lumen thrombosis rates (ESC 2024 Class I, Level B).^[1]

Step 5 — After surgery

Discussion:

• After open surgery for AAS, ESC 2024 says follow-up imaging by CCT and TTE within 6 months, then CCT at 12 months and yearly if findings are stable (in extent of residual false lumen and aortic diameters at any level), should be considered (Class IIa, Level B).^[1]
• ACC/AHA 2022: in patients who have had an acute aortic dissection and intramural haematoma (IMH) treated with either open or endovascular aortic repair and who have residual aortic disease, surveillance imaging with computed tomography (CT), or magnetic resonance imaging (MRI), is recommended after 1, 6 and 12 months and then, if stable, annually (COR 1, LOE B-NR).^[2]
• ACC/AHA 2022 recommends long-term beta-blockers (unless contraindicated) to control heart rate and BP and reduce late aortic adverse events (COR 1, LOE B-NR).^[2]
• In acute type A dissection, ACC/AHA 2022 recommends recording the aortic root and ascending aortic diameters in the operative note and medical record to inform the management of affected relatives (COR 1, LOE C-EO).^[2]
• ESC 2024 recommends gathering family history over at least three generations about thoracic aortic disease, unexplained sudden deaths, and peripheral and intracranial aneurysms after thoracic aortic dissection (Class I, Level B).^[1]