What criteria are used to choose a specific dose of aspirin in ischemic stroke?

In my training and current practice, most stroke specialists have adjusted from the standard 81 mg aspirin dose (one-size-fits-all) to weight-based dosing. A meta-analysis of RCTs (Rothwell et al., PMID 30017552) suggests that low-dose aspirin may not suffice for stroke prophylaxis for patients who ...

For most patients, I use 81 mg of aspirin for secondary stroke prevention. If the patient had a TIA or stroke on that dose of aspirin, I sometimes increase the dose to 162 mg or 325 mg (if the patient might have aspirin resistance).

I worry about the aspirin dose as splitting hairs. The difference in absolute risk reduction between 81 mg, 162 g, and 325 mg is minimal. It's much more important for secondary preventive measures to focus on diet and smoking. However, my practice for aspirin is to load 325 mg so it becomes therapeu...