What are the guidelines for managing a patient with suspected aortic dissection, likely with a history of hypertension and possible comorbidities such as coronary artery disease or peripheral vascular disease?

Management of Aortic Dissection

Immediate Diagnostic Approach

CT angiography from neck to pelvis is the first-line imaging technique for suspected aortic dissection, as it is widely available, accurate, and provides critical information about the entry tear, extension, and complications including malperfusion, dilatation, or rupture. 1

• Transesophageal echocardiography (TOE) is recommended to guide peri-operative management and detect complications in patients with suspected acute aortic syndrome 1
• In the pre-hospital setting, the ADD (Aortic Dissection Detection) score is highly recommended for risk stratification 1
• Point-of-care focused ultrasound (FoCUS) echocardiography may be considered to support the diagnosis in the pre-hospital setting 1

Immediate Medical Management: The Critical First Hour

Intravenous beta-blockers must be initiated immediately as the first-line pharmacologic intervention to achieve a target heart rate <60 beats/min before addressing blood pressure. 2, 3

Hemodynamic Targets

• Target systolic blood pressure: 100-120 mmHg 1, 2, 4, 3
• Target heart rate: <60 beats/min 1, 2, 3
• Beta-blockers should be started before any other antihypertensive drugs to reduce aortic wall shear stress by decreasing the force of left ventricular ejection 2
• Intravenous esmolol is preferred given its ultra-short half-life, allowing rapid titration if complications develop 2

Sequential Blood Pressure Control

• If blood pressure remains >120 mmHg despite adequate beta-blockade, add intravenous vasodilators such as sodium nitroprusside or nitrates 1, 4, 3
• Never use vasodilators without prior beta-blockade, as unopposed vasodilation can increase aortic wall shear stress 3
• If the patient has a contraindication to beta-blockers, a non-dihydropyridine calcium channel blocker should be considered 1

Critical Contraindications

Antithrombotic therapy, antiplatelet agents, and thrombolytics are absolute contraindications in suspected aortic dissection, as they can cause catastrophic hemorrhage into the dissection. 1, 2

• This applies even when ECG changes suggest myocardial ischemia 2
• Withholding antithrombotic therapy in suspected aortic dissection is mandatory 1

Transfer and Triage Strategy

Patients with very high probability of aortic dissection (ADD score ≥1) must be transferred to a center with 24/7 available aortic imaging and cardiac surgery. 1

• Transfer from a low- to a high-volume aortic center with a multidisciplinary team should be considered to improve survival if transfer can be accomplished without significant delay in surgery 1
• For diagnosed or highly suspected acute type A dissection, direct admission to the operating room (hybrid-OR) with onsite aortic team is recommended 1
• Activation of aortic imaging and cardiac surgery with admission directly to radiology before proceeding to the operating theater may be considered 1

Type-Specific Surgical Management

Type A Acute Aortic Dissection (Ascending Aorta)

Immediate aortic surgery is recommended for all type A dissections, as mortality approaches 1-2% per hour without intervention. 1, 2

Surgical Approach Based on Anatomy:

• Aortic root involvement: If extensive destruction of the aortic root, a root aneurysm, or a known genetic aortic disorder exists, aortic root replacement is recommended with a mechanical or biological valved conduit 1
• Partially dissected root: If the aortic root is partially dissected but no significant aortic valve leaflet pathology exists, aortic valve resuspension is recommended over valve replacement 1
• Arch involvement: In patients without an intimal tear in the arch or significant arch aneurysm, hemi-arch repair is recommended over more extensive arch replacement 1
• Extended dissection: If a secondary intimal tear exists in the arch or proximal descending thoracic aorta, extended aortic repair with stenting of the proximal descending aorta (frozen elephant trunk technique) may be considered to reduce late distal aortic complications 1
• An open distal anastomosis is recommended to improve survival and increase false lumen thrombosis rates 1

Type A Dissection with Malperfusion

In patients with acute type A dissection presenting with malperfusion (cerebral, mesenteric, lower limb, or renal), immediate aortic surgery is recommended. 1

• For cerebral malperfusion or non-hemorrhagic stroke, immediate aortic surgery should be considered to improve neurological outcome and reduce mortality 1
• For clinically significant mesenteric malperfusion syndrome, immediate invasive angiographic diagnostics to evaluate percutaneous malperfusion repair before or directly after aortic surgery should be considered in aortic centers with expertise 1
• If malperfusion persists after aortic surgery, optional angiographic control and/or percutaneous malperfusion repair/TEVAR/EVAR should be considered 1

Type B Acute Aortic Dissection (Descending Aorta)

Uncomplicated acute type B dissection should be managed medically with aggressive blood pressure and heart rate control, with TEVAR considered in the subacute phase (14-90 days) in selected patients with high-risk features. 1, 4

Complicated Type B Dissection Requiring Intervention:

• Aortic rupture or impending rupture 1
• Refractory hypertension despite maximal medical therapy 1
• Persistent or recurrent pain 1
• Malperfusion syndromes (cerebral, mesenteric, lower extremity) 1
• Rapid aortic expansion 1

For complicated type B dissection, TEVAR or EVAR and/or percutaneous malperfusion repair is recommended. 1

• In case of retrograde type A dissection, immediate aortic surgery (ascending aorta, aortic arch, or frozen elephant trunk based on extension) is recommended 1

Chronic Type B Dissection

• With descending thoracic aortic diameter ≥60 mm, treatment is recommended in patients at reasonable surgical risk 1
• With descending thoracic aortic diameter ≥55 mm, intervention should be considered in patients with low procedural risk 1
• For chronic post-dissection thoracoabdominal aortic aneurysms, fenestrated/branched stent grafts may be considered when treatment is indicated 1

Transition to Oral Therapy

After 24 hours of hemodynamic stability with intravenous anti-impulse therapy, switching to oral beta-blockers and, if necessary, up-titration of other blood pressure-lowering agents is recommended if gastrointestinal transit is preserved. 1

• Target long-term blood pressure <135/80 mmHg 3

Follow-Up Imaging Protocols

After TEVAR for Acute Aortic Syndrome:

• Follow-up imaging is recommended at 1,6, and 12 months post-operatively, then yearly until the fifth post-operative year if no abnormalities are documented 1

Medically Treated Type B Dissection or Intramural Hematoma:

• Follow-up imaging is recommended at 1,3,6, and 12 months after onset, then yearly if imaging findings are stable 1

After Open Surgery for Acute Aortic Syndrome:

• Follow-up imaging by CCT and TTE within 6 months, then CCT at 12 months and yearly if findings are stable, should be considered 1
• If no complications occur within the first 5 years, CCT every 2 years thereafter should be considered 1
• If no residual patent false lumen is documented for 3 post-operative years, subsequent surveillance by CCT every 2-3 years should be considered 1

Common Pitfalls to Avoid

• Never administer vasodilators before beta-blockade – this can paradoxically increase aortic wall stress 3
• Never give thrombolytics for ECG changes – even if myocardial infarction is suspected, aortic dissection must be ruled out first 1, 2
• Never delay surgery for extensive imaging – in unstable type A dissection, proceed directly to the operating room with intraoperative TOE 1
• Never use vasopressors if avoidable – they may cause further false lumen propagation 3