Makindo Medical Notes

Related Subjects: | Atrial Flutter | Atrial Fibrillation | AF and Anticoagulation | AF and Rate Control | AF and Rhythm Control and Cardioversion | AF ECG | DC Cardioversion

🧠 About Stroke Risk Assessment in Atrial Fibrillation

• 📊 CHADS₂ and CHA₂DS₂-VASc scores are used to estimate stroke risk in AF.
• 💊 Warfarin reduces stroke risk by ~66% in AF patients.
• 🩸 For bleeding risk assessment, use the HAS-BLED score.

🧮 CHADS₂ Score

• 💔 Congestive heart failure: +1
• 🩺 Hypertension: +1
• 🎂 Age ≥ 75: +1
• 🍬 Diabetes: +1
• 🧠 Previous TIA/Stroke: +2

📈 CHADS₂ Event Rates

• Score 0–1: ⚖️ 1.9–2.8% per 100 pt-years
• Score 2–4: 📉 4.0–5.9% per 100 pt-years
• Score 5–6: 🚨 12.5–18.2% per 100 pt-years

🧮 CHA₂DS₂-VASc Score

• 💔 CHF: +1
• 🩺 Hypertension: +1
• 🎂 Age ≥ 75: +2
• 🎂 Age 65–74: +1
• 🍬 Diabetes: +1
• 🫀 Vascular disease (MI, PAD, aortic plaque): +1
• 🧠 Stroke/TIA/Thromboembolism: +2
• 👩 Female sex: +1

📊 CHA₂DS₂-VASc Event Rates

• Score 0–2: ⚖️ 0–1.6% per 100 pt-years
• Score 5: 📉 3.2% per 100 pt-years
• Score 7: ⚠️ 8.0% per 100 pt-years
• Score ≥8: 🚨 15.2% per 100 pt-years

💊 Anticoagulation Recommendations

• Score 0: 🚫 No anticoagulation.
• Score 1 (Males): 🤔 Consider anticoagulation.
• Score 1 (Females): ❌ No anticoagulation if due solely to sex.
• Score ≥ 2: ✅ Anticoagulation recommended.

📚 References

• CHA₂DS₂-VASc Score Research

🩺 Case 1 — Young Patient, Low Stroke Risk

A 58-year-old man with newly diagnosed paroxysmal atrial fibrillation. He has no hypertension, diabetes, vascular disease, or heart failure. CHA₂DS₂-VASc score = 0. Management: 📝 No anticoagulation needed (low risk). Discuss lifestyle and risk factor modification (BP, weight, alcohol, sleep apnoea). Benefits of anticoagulation: 🚫 Minimal in this case (stroke risk <1% per year). Risks: ❌ Unnecessary bleeding risk would outweigh benefit.

🩺 Case 2 — Typical Older Patient with Risk Factors

A 74-year-old woman with persistent AF, hypertension, and type 2 diabetes. CHA₂DS₂-VASc = 4. Management: 💊 Anticoagulation strongly indicated. A DOAC (e.g., apixaban, rivaroxaban, dabigatran, edoxaban) is usually first-line. Warfarin considered if contraindication or poor renal function. Benefits: ✅ Major reduction in embolic stroke risk (relative risk reduction ~65%). Risks: ⚠️ Bleeding (especially GI or intracranial), but DOACs generally safer than warfarin for ICH. Careful with renal function.

🩺 Case 3 — Frail Patient with Falls

An 82-year-old man with permanent AF, previous TIA, hypertension, and moderate frailty. He has a history of falls and bruising. CHA₂DS₂-VASc = 5; HAS-BLED = 3. Management: ⚖️ Anticoagulation still usually offered — stroke risk is very high. DOAC at adjusted dose is preferred. Falls risk is < stroke risk in most cases. Regular medication review essential. Benefits: ✅ Substantial stroke prevention (risk reduction outweighs bleed risk). Risks: ❌ Increased risk of major bleed, especially if polypharmacy or renal impairment. Falls alone are rarely a contraindication — discuss with patient/family.