What is the appropriate management for a suspected aortic dissection in an adult patient over 50 with hypertension, atherosclerosis, or connective tissue disorders?

Management of Suspected Aortic Dissection

Immediate Hemodynamic Control

In adult patients with suspected or confirmed acute aortic dissection, immediately reduce blood pressure and heart rate if elevated, targeting heart rate <60 beats per minute and systolic blood pressure 100-120 mmHg to prevent dissection progression and rupture. 1, 2

• The leading cause of death is progressive dissection resulting in rupture, driven by pulsatile blood flow and shear forces on the aortic wall 1
• Beta-blockers should be first-line agents to reduce both heart rate and blood pressure 2
• Measure blood pressure in all four extremities to identify the highest central pressure, as dissection may cause falsely low readings in affected limbs 2
• Provide adequate analgesia for pain control as part of initial stabilization 2

Important caveat: Aggressive blood pressure reduction can cause adverse events in select patients with severe aortic insufficiency or pericardial tamponade 1

Diagnostic Imaging Strategy

Use CT angiography (CTA) as the primary diagnostic test to exclude thoracic aortic dissection, as it has diagnostic accuracy equivalent to transesophageal echocardiography (TEE) and magnetic resonance angiography (MRA). 1

• CTA has sensitivity of 93% (95% CI 90-95%) and specificity near 100% 1
• CTA offers the advantages of rapid availability, quick diagnosis, and identification of alternative diagnoses in 13% of cases without aortic pathology 1
• TEE has sensitivity of 88% (95% CI 82-92%) but is less readily available in most emergency departments 1
• MRA has sensitivity approaching 100% but is time-consuming and less practical in unstable patients 1

Role of Bedside Transthoracic Echocardiography (TTE)

Do not rely on bedside TTE to definitively establish or exclude the diagnosis of thoracic aortic dissection. 1

• TTE has limited sensitivity (59-80%) and variable specificity (0-100%) for detecting aortic dissection 1
• However, if TTE is suggestive of aortic dissection in an unstable patient, immediately obtain surgical consultation or arrange transfer to a higher level of care 1
• This approach allows rapid triage of hemodynamically unstable patients who cannot safely undergo CTA 1

D-dimer Limitations

Do not use a negative D-dimer alone to exclude aortic dissection, even though it has high sensitivity (91-100%). 3

• False-negative D-dimer results occur in chronic dissections, thrombosed false lumen, intramural hematoma without intimal flap, short dissection length, and young patients 3
• D-dimer >0.5 µg/mL may support clinical suspicion but should not drive decision-making 3
• If clinical suspicion persists, proceed directly to CTA regardless of D-dimer result 3

Clinical Risk Stratification

Maintain high clinical suspicion in patients with high-risk predisposing conditions, high-risk pain features, or high-risk examination findings. 3

High-Risk Predisposing Conditions:

• Marfan syndrome or other connective tissue disorders 1, 3, 4, 5
• Family history of aortic disease 3
• Known aortic valve disease (especially bicuspid aortic valve) 1, 3
• Recent aortic manipulation or cardiac surgery 3
• Known thoracic aortic aneurysm 3
• Hypertension and atherosclerosis 4, 5

High-Risk Pain Features:

• Abrupt onset (present in 84% of cases) 3
• Severe intensity (present in 90% of cases) 3
• Chest pain (80% of Type A dissections, typically anterior) 3
• Back pain, especially interscapular (64% of Type B dissections, 47% of Type A) 3
• Migrating pain quality (12-55% of cases) 3

High-Risk Examination Findings:

• Pulse deficit or blood pressure differential between extremities 3
• New murmur of aortic insufficiency 3
• Focal neurologic deficits with pain 3

Critical pitfall: Up to 6.4% of patients present without pain, particularly elderly patients, those on steroids, and patients with Marfan syndrome 3. These patients more commonly present with syncope, stroke, or congestive heart failure 3, 2.

Clinical Decision Rules

Do not rely solely on clinical decision rules (such as the ADD score) to identify low-risk patients and avoid imaging. 3

• Even patients with an ADD score of 0 have a 4.3-5.9% risk of dissection 3
• Clinical judgment should guide the decision to pursue imaging, not algorithmic risk scores alone 1, 3

Definitive Management Based on Dissection Type

Type A Dissection (Ascending Aorta/Arch)

Emergency surgical repair is the treatment of choice for Type A dissection, as surgery significantly reduces mortality compared to medical management alone. 2, 4, 5, 6

• Type A dissections have the highest mortality and require immediate surgical consultation 1
• Surgical approach includes resection of all aneurysmal aorta and proximal dissection extent, with consideration of aortic valve resuspension or root replacement 2
• Transesophageal echocardiography is reasonable during all open surgical repairs unless contraindicated 2
• In elderly patients up to age 80, surgical management has significantly lower in-hospital mortality than medical treatment 2

Type B Dissection (Descending Aorta)

Most Type B dissections are managed medically with aggressive blood pressure and heart rate control, unless complicated by malperfusion, rupture, or progression. 1, 4, 5

• Endovascular intervention is indicated for complicated Type B dissections 4, 5
• Medical management alone is appropriate for uncomplicated Type B dissections 1, 4

Special Population Considerations

Elderly Patients

• Less likely to present with typical abrupt onset pain, murmur of aortic regurgitation, or pulse deficits 2
• More likely to present with altered mental status or congestive heart failure 2
• Age alone should not exclude patients from surgical consideration up to age 80 2
• Key predictors of postoperative complications include preoperative renal dysfunction, chronic pulmonary disease, and cerebrovascular disease 2

Women

• Present at older age and are less likely to present within the first 6 hours 3
• Have higher in-hospital mortality (30% vs 21% in men) 3