:::1. Why Stroke Prevention is Important in AF
- AF increases stroke risk about 5-fold compared to the general population.
- Most strokes in AF are cardioembolic (due to clot formation in the left atrial appendage).
- Strokes related to AF are often more severe and disabling than other ischemic strokes.
2. Risk Stratification: CHA₂DS₂-VASc Score
This score helps decide whether anticoagulation is needed.
- C: Congestive heart failure – 1 point
- H: Hypertension – 1 point
- A₂: Age ≥ 75 – 2 points
- D: Diabetes – 1 point
- S₂: Prior stroke / TIA / thromboembolism – 2 points
- V: Vascular disease (MI, PAD, aortic plaque) – 1 point
- A: Age 65–74 – 1 point
- Sc: Sex category (female) – 1 point
👉 Anticoagulation generally indicated in:
- Men with score ≥ 2
- Women with score ≥ 3
3. Anticoagulation Options
Direct Oral Anticoagulants (DOACs, first-line in most cases)
- Apixaban, Rivaroxaban, Edoxaban, Dabigatran
- Advantages: predictable effect, no routine INR monitoring, lower intracranial hemorrhage risk than warfarin.
Vitamin K Antagonist (Warfarin)
- Indicated if DOACs contraindicated (e.g., mechanical heart valves, severe mitral stenosis).
- Requires INR monitoring (target 2.0–3.0).
Special Cases
- Mechanical heart valves or severe mitral stenosis → Warfarin is mandatory.
- Renal impairment → Dose adjust or consider warfarin.
4. Non-Pharmacologic Stroke Prevention
- Left atrial appendage closure (e.g., WATCHMAN device):
- For patients at high thromboembolic risk but who cannot tolerate anticoagulation.
- Surgical ligation/excision of LAA: sometimes performed during cardiac surgery.
5. Antiplatelet Therapy
- Aspirin alone is not recommended for stroke prevention in AF (much less effective than anticoagulation).
- Dual antiplatelet therapy (aspirin + clopidogrel) may be considered only if anticoagulants are contraindicated.
6. Bleeding Risk Assessment: HAS-BLED Score
- H = Hypertension
- A = Abnormal renal/liver function
- S = Stroke history
- B = Bleeding history
- L = Labile INR
- E = Elderly (>65)
- D = Drugs/alcohol
👉 High score doesn’t mean “no anticoagulation” but requires closer monitoring and risk modification.
✅ Summary:
Stroke prevention in AF relies mainly on oral anticoagulation, guided by CHA₂DS₂-VASc score. DOACs are preferred unless contraindicated. Warfarin is used in special cases. Non-drug options (e.g., LAA closure) are reserved for those who cannot take anticoagulants. Antiplatelets alone are not sufficient.
1. 为什么需要卒中预防
- 心房颤动会使卒中风险增加 约 5 倍。
- 大多数与 AF 有关的卒中是 心源性栓塞（血栓形成于左心耳）。
- AF 相关卒中通常更严重，致残率和死亡率更高。
2. 卒中风险评估：CHA₂DS₂-VASc 评分
该评分用于决定是否需要抗凝：
- C：充血性心力衰竭 – 1 分
- H：高血压 – 1 分
- A₂：年龄 ≥ 75 岁 – 2 分
- D：糖尿病 – 1 分
- S₂：既往卒中 / TIA / 栓塞 – 2 分
- V：血管疾病（心肌梗死、外周动脉病变、主动脉粥样硬化） – 1 分
- A：年龄 65–74 岁 – 1 分
- Sc：女性 – 1 分
👉 建议抗凝：
- 男性：分数 ≥ 2
- 女性：分数 ≥ 3
3. 抗凝治疗选择
直接口服抗凝药（DOACs，一线用药）
- 阿哌沙班、利伐沙班、依度沙班、达比加群
- 优点：药效可预测，无需常规 INR 监测，颅内出血风险低于华法林。
维生素 K 拮抗剂（华法林）
- 适用于 DOACs 禁忌时（如机械瓣膜、重度二尖瓣狭窄）。
- 需要 INR 监测（目标 2.0–3.0）。
特殊情况
- 机械心脏瓣膜 / 重度二尖瓣狭窄 → 必须使用华法林。
- 肾功能不全 → 需要调整 DOAC 剂量或使用华法林。
4. 非药物性卒中预防
- 左心耳封堵（如 WATCHMAN 装置）：适合高血栓风险但无法耐受抗凝药的患者。
- 左心耳外科结扎/切除：有时在心脏手术时进行。
5. 抗血小板治疗
- 单用阿司匹林 不推荐 作为 AF 卒中预防。
- 双联抗血小板（阿司匹林 + 氯吡格雷）仅在抗凝绝对禁忌时可考虑。
6. 出血风险评估：HAS-BLED 评分
- H = 高血压
- A = 异常肾/肝功能
- S = 既往卒中
- B = 出血史
- L = INR 控制不稳定
- E = 老年（>65 岁）
- D = 药物/酒精
👉 高分并非“不抗凝”，而是提示需要 更严格监测并纠正可控危险因素。
✅ 总结：
AF 的卒中预防主要依靠 口服抗凝治疗，根据 CHA₂DS₂-VASc 评分决定是否用药。DOACs 为首选，华法林用于特定患者。非药物方案（如左心耳封堵）适用于无法使用抗凝药的人群。单独抗血小板不足以有效预防卒中。