In a hypertensive, diabetic patient with chest pain radiating to the back, should I obtain an emergent contrast‑enhanced computed tomography angiogram of the chest (CT aortogram) before initiating antiplatelet or anticoagulant therapy?

Obtain CT Aortogram BEFORE Antiplatelet/Anticoagulant Therapy

In a hypertensive, diabetic patient with chest pain radiating to the back, you should obtain an emergent contrast-enhanced CT aortogram BEFORE initiating antiplatelet or anticoagulant therapy, as this presentation pattern represents a high-risk feature for acute aortic dissection, and administering antithrombotic agents could cause catastrophic hemorrhage if dissection is present. 1

Why CT Takes Priority in This Clinical Scenario

High-Risk Features for Aortic Dissection

• Pain radiating to the back is a high-risk feature that establishes elevated pretest probability for acute aortic dissection (AoD), particularly when combined with hypertension 1
• The combination of two or more high-risk features (hypertension as a high-risk condition + back radiation as high-risk pain characteristic) is strongly suggestive of acute AoD and triggers immediate concern 1
• Missed or delayed diagnosis of acute AoD is most commonly caused by an incorrect working diagnosis of acute coronary syndrome, which may require prolonged time to identify and whose management with antiplatelet and antithrombin agents may cause harm to the patient with dissection 1

The Critical Timing Issue

• For patients with an intermediate-risk profile for acute AoD who do not have diagnostic ST-elevation myocardial infarction but are being evaluated for possible acute coronary syndrome, aortic imaging may detect AoD prior to the administration of antiplatelet and antithrombin agents 1
• This sequencing is essential because anticoagulation and antiplatelet therapy can precipitate life-threatening hemorrhage in the setting of aortic dissection 1
• Multidetector CT provides acceptable diagnostic accuracy for the diagnosis of acute AoD and is the preferred initial imaging modality in hemodynamically stable patients 1

Diagnostic Algorithm for This Patient

Step 1: Immediate Assessment (Within 10 Minutes)

• Obtain 12-lead ECG within 10 minutes to identify ST-elevation ≥1 mm in contiguous leads or new left bundle branch block 2, 3
• Place patient on continuous cardiac monitoring with defibrillation capability 2, 4
• Measure blood pressure in both arms and assess for pressure differences caused by aortic dissection 1
• Draw cardiac troponin immediately (but do NOT wait for results before imaging) 3, 4

Step 2: Risk Stratification for Aortic Dissection

Proceed directly to CT aortogram if:

• Pain described as abrupt/instantaneous onset, severe intensity, or ripping/tearing quality 1
• Hypertension present (as in this patient) 1
• Pain radiating to back (as in this patient) 1
• Blood pressure differential between arms >20 mmHg 1
• Widened mediastinum on chest x-ray 1

Step 3: CT Aortogram Protocol

• Obtain contrast-enhanced CT angiography of the chest (CT aortogram) emergently to exclude aortic dissection before any antithrombotic therapy 1
• This imaging provides 100% sensitivity and specificity for aortic dissection 1
• Non-ECG-gated contrast-enhanced CT can simultaneously assess for acute aortic dissection, pulmonary embolism, and acute coronary syndrome through detection of myocardial perfusion deficits 5

Step 4: Treatment Based on CT Results

If CT shows aortic dissection:

• DO NOT administer antiplatelet or anticoagulant therapy 1
• Initiate blood pressure control with IV beta-blockers targeting systolic BP 100-120 mmHg 1
• Activate cardiovascular surgery immediately 1

If CT excludes aortic dissection:

• NOW initiate acute coronary syndrome management with aspirin 162-325 mg and clopidogrel loading dose 1, 2, 3
• Start unfractionated heparin or enoxaparin 1
• Administer IV morphine 4-8 mg for pain relief 2, 4
• Give sublingual nitroglycerin if systolic BP >90 mmHg 2
• Initiate IV beta-blocker if ongoing chest pain without contraindications 1

Special Considerations for This Diabetic, Hypertensive Patient

Diabetes-Specific Factors

• Diabetic patients may present with atypical symptoms due to autonomic dysfunction, making clinical diagnosis more challenging 2, 3
• These patients have accelerated atherosclerosis and hyperreactive platelets, increasing both ACS and thrombotic risk once dissection is excluded 6
• After ruling out dissection, dual antiplatelet therapy is particularly important as diabetic patients show impaired response to antiplatelet agents 7, 6

Hypertension Management

• Blood pressure should be controlled to <130/80 mmHg if myocardial injury is confirmed (after dissection excluded) 3
• In hypertensive emergencies with suspected end-organ damage, the rate of BP increase is more important than absolute value 1
• ACE inhibitors are recommended when hypertension persists despite nitroglycerin and beta-blockers, particularly in diabetic patients 1

Common Pitfalls to Avoid

Do Not Assume ACS Without Imaging

• Approximately 40% of chest films in acute aortic dissection lack widened mediastinum, and 16% are completely normal, so absence of radiographic abnormalities does not exclude dissection 1
• The presence of ST-segment changes on ECG does not exclude aortic dissection, as approximately 10-15% of dissections involve the coronary ostia causing myocardial ischemia 1

Do Not Delay CT for Troponin Results

• Do not wait for troponin results before obtaining CT aortogram in patients with high-risk features for dissection 1
• Troponin elevation can occur in both ACS and aortic dissection involving coronary arteries 1

Coordinate with Interventional Team

• If proceeding to cardiac catheterization after CT excludes dissection, coordinate anticoagulation strategy with the catheterization laboratory, as some prefer not to perform procedures on patients receiving low-molecular-weight heparin 1
• Enoxaparin is preferred over unfractionated heparin unless coronary artery bypass grafting is planned within 24 hours 1