**3. Bleeding risk evaluation**

In choosing the antithrombotic therapy regime, both the risk of bleeding and the evaluation of thromboembolic risk are important. The use of VKA causes a more meaningful decrease in embolic risk compared to aspirin alone or DAPT (dual antiplatelet therapy) in patients with a medium and high risk. However the use of VKA increases the risk of major bleeding especially when used with DAPT. Therefore, determining the risk of bleeding is important before starting the therapy. Although various risk scores evaluating the risk of bleeding have been obtained, they were all developed to estimate the risk of major bleeding and they can be classified into three groups as low, medium and advanced. ESC guidelines recom‐ mend using HAS-BLED scoring [Table 2] (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly (>65), drugs/alcohol concomi‐ tantly) in the estimation of bleeding risk [9]. HAS-BLED≥3 was found to be related to high risk of bleeding. However, parameters such as a history of stroke, old age, and hypertension also affect the risk of emboli estimated by using the CHA₂DS₂-Vasc-Score,. Thus, patients with a high bleeding risk must be carefully managed.


\*Hypertension' is defined as systolic blood pressure >160 mmHg. 'Abnormal kidney function' is defined as the pres‐ ence of chronic dialysis or renal transplantation or serum creatinine ≥200 mmol/L. 'Abnormal liver function' is defined as chronic hepatic disease (e.g. cirrhosis) or biochemical evidence of significant hepatic derangement (e.g. bilirubin >2 x upper limit of normal, in association with aspartate aminotransferase/alanine aminotransferase/alkaline phospha‐ tase >3 x upper limit normal, etc.). 'Bleeding' refers to previous bleeding history and/or predisposition to bleeding, e.g. bleeding diathesis, anaemia, etc. 'Labile INRs' refers to unstable/high INRs or poor time in therapeutic range (e.g., 60%). Drugs/alcohol use refers to concomitant use of drugs, such as antiplatelet agents, non-steroidal anti-inflamma‐ tory drugs, or alcohol abuse, etc. INR = international normalized ratio. Adapted from Pisters et al (9).

**Table 2.** HAS-BLED bleeding score

Vasc-Score [6] derived from a European Heart Survey were found to be beneficial for esti‐ mation of the risk of stroke. This scoring system is suggested for risk stratification in both the European Society of Cardiology (ESC) [7] and the American College of Cardiology/ American Heart Association (ACC/AHA) [8] guidelines. (Table1). According to this scoring system, the patients are stratified into three risk groups as low (0), medium (1 – 2) and high (>2). While the risk of emboli is 1.3 % at score 1, the risk increases to 15.2 % at score 9. While previous embolism/TIA/stroke and age ≥75 are the major risk factors, the other clinical situa‐ tions are classified as the non-major risk factors. Not only previous myocardial infarction but also complex atheroma plaques and peripheral vascular disease have also been included

> **Letter Clinical Condition and age Points** C Congestive heart failure† 1 H Hypertension 1 A Age≥75 years 2 D Diabetes mellitus 1 S Stroke/TIA/Thromboembolism 2 V Vascular disease\* 1 A Age 65 – 74 1 S Female sex 1

†Heart failure or moderate to severe left ventricular systolic dysfunction (e.g. LV EF < 40%)

**Table 1.** CHA₂DS₂-Vasc-Score for determining embolic risk

**3. Bleeding risk evaluation**

\*Prior myocardial infarction, peripheral artery disease, aortic plaque. TIA =transient ischaemic attack.

In choosing the antithrombotic therapy regime, both the risk of bleeding and the evaluation of thromboembolic risk are important. The use of VKA causes a more meaningful decrease in embolic risk compared to aspirin alone or DAPT (dual antiplatelet therapy) in patients with a medium and high risk. However the use of VKA increases the risk of major bleeding especially when used with DAPT. Therefore, determining the risk of bleeding is important before starting the therapy. Although various risk scores evaluating the risk of bleeding have been obtained, they were all developed to estimate the risk of major bleeding and they can be classified into three groups as low, medium and advanced. ESC guidelines recom‐ mend using HAS-BLED scoring [Table 2] (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR, elderly (>65), drugs/alcohol concomi‐

max. 9 points

in the definition of vascular disease.

230 Atrial Fibrillation - Mechanisms and Treatment
