What is the comparison between Treat-CAD (Treatment of Carotid Artery Disease) and CADISS (Cervical Artery Dissection in Stroke Study) trials?

Comparison Between CADISS and Treat-CAD Trials

The CADISS (Cervical Artery Dissection in Stroke Study) trial showed no significant difference in efficacy between antiplatelet and anticoagulant therapy for cervical artery dissection, while there is no evidence of a Treat-CAD trial in the provided literature.

CADISS Trial Overview

Design and Population

• CADISS was a randomized, open-label international multicenter trial conducted in 46 centers (39 in UK, 7 in Australia) 1
• Enrolled 250 patients with extracranial carotid and vertebral artery dissection with symptom onset within 7 days 1
• Mean time to randomization was 3.65 days after symptom onset 1
• Patients were randomized to either antiplatelet therapy or anticoagulation therapy for 3 months 1

Key Findings

• Primary outcome: The rate of ipsilateral stroke or death was very low in both groups:
  • Antiplatelet group: 3 events (2%)
  • Anticoagulant group: 1 event (1%)
  • Odds ratio 0.335 (95% CI 0.006-4.233; p=0.63) 1
• Long-term follow-up at 1 year showed similarly low recurrent stroke rates (2.4% overall) 2
• No deaths occurred, but one major bleeding event (subarachnoid hemorrhage) was reported in the anticoagulant group 1
• Central review of imaging failed to confirm dissection in 52 patients (21% of cases) 1

Clinical Implications

• The 2021 AHA/ASA guidelines incorporated CADISS findings, stating: "In patients with ischemic stroke or TIA who are <3 months after an extracranial carotid or vertebral arterial dissection, it is reasonable to use either aspirin or warfarin to prevent recurrent stroke or TIA" (Class 2a, Level B-R) 3
• The guidelines recommend antithrombotic therapy for at least 3 months after cervical artery dissection (Class 1, Level C-EO) 3

Treat-CAD Trial

There is no evidence of a "Treat-CAD" (Treatment of Carotid Artery Disease) trial in the provided literature. The literature focuses on:

1. Carotid endarterectomy (CEA) for carotid stenosis
2. Carotid artery stenting (CAS) for carotid stenosis
3. CADISS trial for cervical artery dissection

Important Distinctions in Carotid Pathologies

Carotid Dissection vs. Carotid Stenosis

• Carotid dissection is more common in younger individuals (mean age 40-49 years) 4, 5
• Carotid stenosis is typically an atherosclerotic condition more common in older adults
• Different treatment approaches are required for these distinct pathologies:
  • Dissection: Antithrombotic therapy (antiplatelet or anticoagulation) 3
  • Stenosis: Revascularization (CEA or CAS) for symptomatic stenosis ≥50% 3, 6

Clinical Pearls from CADISS

• The risk of recurrent stroke after cervical artery dissection is much lower than previously reported in observational studies 1
• Diagnostic accuracy is a challenge - 21% of patients initially diagnosed with dissection did not have confirmation on central imaging review 1
• There are distinct differences between carotid and vertebral dissections:
  • Carotid dissections are associated with higher mortality (aOR 1.30) and less routine discharges compared to vertebral dissections 5
  • Carotid dissections have higher NIHSS scores when associated with stroke 5

Treatment Recommendations for Cervical Artery Dissection

Based on the CADISS trial and current guidelines:

1. For acute cervical artery dissection (within 7 days of symptom onset):

   • Either antiplatelet therapy or anticoagulation therapy is reasonable 3, 1
   • Treatment should continue for at least 3 months 3

2. For recurrent events despite antithrombotic therapy:

   • Endovascular therapy may be considered (Class 2b, Level C-LD) 3

3. Monitoring and follow-up:

   • Imaging follow-up to assess vessel recanalization
   • CADISS showed no difference in recanalization rates between antiplatelet and anticoagulant groups 2

Conclusion

The CADISS trial provides important evidence that both antiplatelet and anticoagulant therapies are reasonable options for treating cervical artery dissection, with similarly low rates of recurrent stroke. There is no evidence of a Treat-CAD trial in the provided literature, and it appears this may be a confusion with trials on carotid stenosis treatment rather than dissection.