Secondary stroke prevention

Etiology - Clot Cause Crossroads

• 📌 The 5 P's of Stroke Etiology:
  • Pump (Heart): Cardioembolic (e.g., AFib, valve dz).
  • Pipes (Arteries): Large artery atherosclerosis (e.g., carotid stenosis).
  • Pellets (Small Vessels): Lacunar infarcts from lipohyalinosis.
  • Patent Foramen Ovale (PFO) & other causes.
  • Puzzling: Cryptogenic / ESUS (Embolic Stroke of Undetermined Source).

⭐ ESUS is a key concept; these cryptogenic strokes are suspected to be embolic. Prolonged cardiac monitoring (e.g., Holter) is often required to unmask occult paroxysmal atrial fibrillation.

Antithrombotics - Plaque & Clot Patrol

• Goal: Prevent platelet aggregation (plaque rupture) or thrombus formation (stasis).
• Choice depends on stroke etiology.

• Antiplatelet Options:

  • Aspirin (81-325 mg/day)
  • Clopidogrel (75 mg/day)
  • Aspirin/Dipyridamole ER
  • 💡 Dual antiplatelet therapy (Aspirin + Clopidogrel) for minor strokes/TIAs, short-term (21-90 days).

• Anticoagulation Options:

  • Warfarin (Target INR 2.0-3.0)
  • Direct Oral Anticoagulants (DOACs) preferred: Apixaban, Rivaroxaban.

⭐ For atrial fibrillation, the decision to anticoagulate is guided by the CHA₂DS₂-VASc score, balancing stroke risk against bleeding risk.

Risk Factor Rx - Pressure & Plaque Purge

• Hypertension (Pressure Purge):

  • Goal BP < 130/80 mmHg.
  • First-line agents: ACE inhibitors/ARBs, Thiazide diuretics, or Calcium Channel Blockers.

• Hyperlipidemia (Plaque Purge):

  • High-intensity statin for ALL ischemic stroke patients, regardless of baseline LDL.
  • Atorvastatin 80 mg or Rosuvastatin 20-40 mg.
  • Goal: LDL-C < 70 mg/dL or a ≥50% reduction from baseline.

• Diabetes Mellitus:

  • Target HbA1c < 7.0%.

⭐ For patients with stroke from 70-99% intracranial large artery stenosis, aggressive medical management (dual antiplatelet therapy for 90 days, statins, BP control) is superior to percutaneous stenting (SAMMPRIS trial).

Lifestyle & Glycemia - The Daily Grind

• Diet: Emphasize DASH-style (↓Na, ↑K, ↑fruits/veg) or Mediterranean diet.
• Exercise: Aim for ≥150 min/week of moderate-intensity aerobic activity.
• Weight Management: Target BMI <25 kg/m² to reduce metabolic risk factors.
• Alcohol: Strictly limit to ≤2 drinks/day for men, ≤1 drink/day for women.
• Glycemic Control: Maintain HbA1c <7.0% for most patients with Type 2 Diabetes.

⭐ For T2DM patients, intensive glucose lowering (e.g., HbA1c <6.0%) has not been shown to reduce stroke risk and may increase all-cause mortality.

Interventions - Pipes & Passages

• Carotid Endarterectomy (CEA): For symptomatic stenosis >70%. Consider in asymptomatic patients with stenosis >80%.
  • Carotid Artery Stenting (CAS): An alternative to CEA, especially in patients with high surgical risk.
• Patent Foramen Ovale (PFO) Closure: For cryptogenic stroke in patients age <60 with a significant right-to-left shunt.
• Left Atrial Appendage (LAA) Occlusion: (e.g., Watchman device) as an alternative to long-term anticoagulation in non-valvular AFib.

⭐ In symptomatic patients, CEA provides the greatest mortality benefit for carotid stenosis of 70-99%.

High-Yield Points - ⚡ Biggest Takeaways

• For non-cardioembolic stroke, aspirin is first-line; clopidogrel is an alternative.
• DAPT (aspirin + clopidogrel) is for minor strokes or high-risk TIAs for a limited duration (21-90 days).
• Anticoagulation is indicated for cardioembolic strokes, most commonly from atrial fibrillation.
• All ischemic stroke patients require high-intensity statin therapy (e.g., atorvastatin 80 mg).
• Aggressive blood pressure control (target <130/80 mmHg) is critical.
• Consider carotid endarterectomy for severe ipsilateral stenosis (>70%).