CHA₂DS₂-VASc and HASBLED scores: Implications for thromboembolic prophylaxis in the elderly with atrial fibrillation

Background: The prevalence of atrial fibrillation increases substantially with age. As atrial fibrillation carries a higher risk of thromboembolic events, several scores have been developed to estimate thromboembolic and bleeding risk in order to help with the prophylactic decision. Objective: To determine thromboembolic and bleeding risk of elderly with atrial fibrillation according to CHADS₂, CHA₂DS₂-VASc and HASBLED and its repercussions on thromboembolic prophylaxis. Methods: Retrospective, observational study including 142 consecutively hospitalized patients over 65 years old, with non-valvular atrial fibrillation/flutter. CHADS₂ and CHA₂DS₂-VASc were applied and compared and HASBLED score was used to estimate haemorrhagic risk. The adequacy of prescribed antithrombotic therapy was evaluated. Long-term follow-up of thromboembolic and haemorrhagic events was carried out. Results: None of the elderly patients were allocated to the low-risk category according to CHADS₂ and CHA ₂DS₂-VASc risk stratification. CHADS₂ classified 32 (22.5%) patients at moderate risk, while CHA₂DS ₂-VASc score classified all patients at high risk. Applying the HASBLED score, 57 (40.1%) had high haemorrhagic risk. Although by CHA ₂DS₂-VASc all patients had a formal indication for anticoagulation, only 77 (54.2%) were anticoagulated. Age was found to be a common criteria for withholding oral anticoagulation. The thromboembolic event rate was 2.6% for anticoagulated patients and 11.5% for not anticoagulated ones, while major haemorrhages occurred in 6.5% anticoagulated and 1.5% not anticoagulated patients. Conclusions: All elderly with atrial fibrillation had high thromboembolic risk, better predicted by CHA₂DS ₂-VASc. Anticoagulation, the only factor that can alter prognosis, was underused despite the evidence of the scores. Paradoxically, age alone was frequently considered a contra-indication for anticoagulation.