What are the best practices for diagnosing and managing aortic dissection in older adults with hypertension, atherosclerosis, or connective tissue disorders?

Aortic Dissection: Diagnosis and Management in High-Risk Populations

Clinical Presentation and Recognition

Aortic dissection presents with abrupt-onset severe pain that reaches maximum intensity immediately, unlike myocardial infarction where pain builds gradually—this distinction is critical for diagnosis. 1, 2

Key Clinical Features:

• Pain location predicts dissection type: Retrosternal/anterior chest pain suggests Type A (ascending aorta) dissection in 71% of cases, while interscapular/back pain indicates Type B (descending aorta) dissection in 64% of cases 1, 2
• Pain quality: Described as sharp, stabbing, tearing, or ripping, though only 51-64% use these classic descriptors 3
• Syncope without pain occurs in up to 20% of patients—do not dismiss dissection based on absence of typical pain 1, 2
• Pulse deficits or blood pressure differential between arms strongly suggests dissection 1, 3
• New diastolic murmur of aortic regurgitation indicates proximal dissection with valve involvement 1, 3

High-Risk Patient Populations:

• Typical patient: Male in his 60s with hypertension (present in 65-75% of cases) 1, 2
• Hypertension is the single most important modifiable risk factor 2, 4
• Atherosclerosis increases risk through structural wall degeneration 5, 6
• Connective tissue disorders (Marfan, Loeys-Dietz, Ehlers-Danlos syndromes) cause dissection at younger ages and smaller aortic diameters 5, 4
• Bicuspid aortic valve patients require lifelong beta-blocker therapy for prevention 1, 4

Diagnostic Algorithm

Every patient with suspected aortic dissection requires urgent definitive imaging—do not delay for laboratory tests. 5

Immediate Actions:

1. Measure blood pressure in both arms and all extremities to detect pulse deficits 2, 3
2. Transfer to intensive care unit with invasive arterial blood pressure monitoring 2
3. Administer morphine for pain control 1, 2
4. Obtain 12-lead ECG within 10 minutes to exclude MI before imaging 3

Imaging Modality Selection:

CT angiography of chest, abdomen, and pelvis is the diagnostic test of choice with 100% sensitivity and should be performed immediately in stable patients. 5, 2

• CTA advantages: Fastest, most widely available, visualizes entire aorta, guides surgical planning 5
• TEE or cardiac MRI should be used only if CT is contraindicated or unavailable 5
• TEE sensitivity: 98-100% but requires sedation and may be dangerous in unstable patients 3
• Transthoracic echocardiography has only 60-80% sensitivity for Type A dissection and cannot reliably exclude dissection 5, 3
• Chest X-ray may show mediastinal widening but is normal in many cases—never use to exclude dissection 5, 3

Laboratory Testing:

• D-dimer >0.5 µg/mL has high sensitivity but should never be used alone to rule out dissection 1, 3
• Biomarkers play only a supportive role and should not delay imaging 4

Management Algorithm

Immediate Medical Stabilization (All Patients):

Initiate aggressive blood pressure and heart rate control immediately targeting systolic BP 100-120 mmHg and heart rate ≤60 bpm using intravenous beta-blockers as first-line therapy. 1, 2

1. First-line: IV beta-blockers (esmolol or labetalol) to achieve heart rate ≤60 bpm 1
2. Second-line: Add sodium nitroprusside for severe hypertension despite beta-blockade 1
3. Never give vasodilators before beta-blockade—this increases shear stress and propagates dissection 1

Definitive Management by Dissection Type:

Type A Dissection (Ascending Aorta):

• Emergency surgical repair is mandatory—mortality is 1-2% per hour without surgery 5, 4
• Immediate surgical consultation upon diagnosis 1
• Surgical approach: Composite graft implantation in ascending aorta 1
• In-hospital mortality: 27% even with optimal surgical management 5

Type B Dissection (Descending Aorta):

• Uncomplicated: Medical management with aggressive BP/HR control 1, 2
• Complicated (rupture, malperfusion, ongoing pain, hypotension): Emergency TEVAR (Thoracic Endovascular Aortic Repair) preferred over open surgery 1, 2
• Better prognosis than Type A with medical management alone 5

Special Population Considerations:

Connective Tissue Disorders:

• Marfan, Loeys-Dietz, Ehlers-Danlos patients require lifelong beta-blocker therapy for prevention 1, 4
• Earlier surgical intervention at aortic diameters 4.0-4.5 cm due to dissection risk at smaller diameters 5
• TGFBR1/TGFBR2 mutations: Consider repair at 4.0 cm diameter 5
• MYH11, SMAD3, ACTA2 mutations: Consider repair at 4.5-5.0 cm diameter 5

Pregnant Patients:

• Multidisciplinary team management at specialized centers required 1

Critical Pitfalls to Avoid

Never administer thrombolytics or anticoagulation until dissection is excluded—this is catastrophic and frequently fatal. 1, 3

Common Diagnostic Errors:

• Misdiagnosis as MI leads to thrombolytic administration with fatal outcomes 1, 3
• Relying on "classic tearing pain"—only half of patients describe pain this way 3
• Normal chest X-ray—does not exclude dissection 3
• Absence of hypertension on presentation—25% of young patients are normotensive 5
• Using D-dimer alone to rule out dissection—requires definitive imaging 1, 3

High-Risk Scenarios Requiring Extra Vigilance:

• Elderly patients >70 years present with atypical symptoms more frequently 5
• Young patients <40 years less likely to have typical presentation 5
• Women present later, with atypical symptoms, and have 30% vs 21% mortality compared to men 5

Screening and Prevention

First-degree relatives of patients with thoracic aortic dissection require screening with echocardiography or CT/MRI. 2

Screening Indications:

• Family history of thoracic aortic aneurysm or dissection 2
• Genetic syndromes: Marfan, Loeys-Dietz, Turner syndrome 2
• Bicuspid aortic valve patients 2
• Imaging frequency: Annual echocardiograms if aortic root <4.5 cm; every 6 months if ≥4.5 cm 5