Antiplatelet Therapy After Coiling for Aneurysmal SAH
Routine antiplatelet therapy with ticagrelor or aspirin is NOT recommended after standard coiling of ruptured aneurysms in aneurysmal SAH, as current evidence shows no benefit and potential harm. 1
Primary Guideline Recommendations
The 2023 AHA/ASA guidelines explicitly state that for patients with aSAH from ruptured saccular aneurysms amenable to primary coiling, stents or flow diverters should not be used to avoid higher risk of complications (Class 3: Harm recommendation). 1 This recommendation implicitly addresses antiplatelet use, as these agents are primarily indicated when endovascular devices requiring antiplatelet therapy are deployed.
When Antiplatelet Therapy IS Indicated
Antiplatelet therapy becomes reasonable only in specific scenarios:
- Stent-assisted coiling or flow diverters for wide-neck aneurysms not amenable to clipping or primary coiling (Class 2a recommendation) 1
- Flow diverters for ruptured fusiform/blister aneurysms (Class 2a recommendation) 1
In these situations where device-assisted coiling is necessary, dual antiplatelet therapy (aspirin + clopidogrel or ticagrelor) is typically required, though specific protocols are not detailed in the guidelines. 1
Evidence Against Routine Antiplatelet Use
Post-Coiling Antiplatelet Therapy
The evidence base does not support routine antiplatelet administration after standard coiling:
The ISAT analysis found no benefit from routine antiplatelet use during or after coiling, with a ratio of relative risks of 1.00 (P=0.77) for 1-year outcomes. 2 This large trial analysis representing 1,422 patients showed that centers prescribing antiplatelets routinely had no improved outcomes compared to those that did not.
The MASH trial specifically tested aspirin 100mg daily started within 12 hours after aneurysm treatment and found it did not reduce delayed ischemic neurological deficit (hazard ratio 1.83,95% CI 0.85-3.9). 3 This randomized controlled trial was stopped early after 161 patients because chances of benefit were negligible.
Conflicting Observational Data
Some retrospective studies suggest potential benefits, but these are lower quality evidence:
One 2019 observational study of 580 patients found aspirin independently associated with reduced delayed cerebral ischemia (adjusted OR 0.41, P<0.001), though it increased minor bleeding events. 4 However, this contradicts the higher-quality randomized trial data.
A 2017 nationwide analysis found aspirin users had shorter hospital stays and lower rates of nonroutine discharge, primarily in endovascularly treated patients, but no mortality difference. 5
These observational studies are subject to selection bias and confounding, and should not override the negative randomized trial evidence. 2, 3
Critical Pitfalls to Avoid
Do not routinely prescribe aspirin or ticagrelor after standard coiling without device deployment requiring antiplatelet therapy 1, 2, 3
If antiplatelet therapy is absolutely necessary due to device use (stent-assisted coiling or flow diversion), consultation with both neurosurgery and interventional neuroradiology is essential for risk assessment 6
Monitor for bleeding complications if antiplatelets are used, as even aspirin monotherapy increases minor bleeding events 4
Avoid dual antiplatelet therapy unless specifically indicated by device requirements, as it increases major bleeding risk without additional DCI benefit 4
Blood Pressure Management Takes Priority
Rather than antiplatelet therapy, focus on evidence-based blood pressure management:
- Maintain systolic BP <160 mmHg before aneurysm treatment using short-acting titratable agents 7
- Maintain mean arterial pressure >90 mmHg after securing the aneurysm to prevent delayed cerebral ischemia 7
- Nimodipine 60mg every 4 hours for 21 days is the proven pharmacological intervention (Class 1 recommendation) 8
Ticagrelor-Specific Considerations
No specific evidence exists for ticagrelor use in aSAH after coiling. Given that aspirin (the most studied antiplatelet agent) shows no benefit in randomized trials, and ticagrelor has more potent antiplatelet effects with potentially greater bleeding risk, ticagrelor should not be used routinely after coiling for aSAH. 2, 3