Reasons for and consequences of vitamin K antagonist discontinuation in very elderly patients with non‐valvular atrial fibrillation

• Published in: Journal of thrombosis and haemostasis Vol. 14; no. 11; pp. 2124 - 2131
• Main Authors: Bertozzo, G., Zoppellaro, G., Granziera, S., Marigo, L., Rossi, K., Petruzzellis, F., Perissinotto, E., Manzato, E., Nante, G., Pengo, V.
• Format: Journal Article
• Language: English
• Published: England Elsevier Limited 01-11-2016
• Subjects: Aged, 80 and over; Anticoagulants - therapeutic use; atrial fibrillation; Atrial Fibrillation - drug therapy; Blood Coagulation; Cardiac arrhythmia; elderly; Female; Fibrinolytic Agents - therapeutic use; Follow-Up Studies; frail; Health risk assessment; Hemorrhage; Humans; Male; Multivariate Analysis; patient compliance; Proportional Hazards Models; Risk Factors; Stroke - etiology; Thromboembolism - mortality; Thromboembolism - therapy; Treatment Outcome; Vascular Diseases - blood; Vitamin K - antagonists & inhibitors; Warfarin - therapeutic use; warfarin suspension; patient compliance; warfarin suspension; atrial fibrillation; frail; elderly
• ISSN: 1538-7933; 1538-7836; 1538-7836
• DOI: 10.1111/jth.13427

Essentials
Anticoagulation in the elderly is still a challenge and suspension of warfarin is common.
This is an observational study reporting reasons and consequences of warfarin suspension.
Vascular disease, age, time in therapeutic range, and bleedings are associated with suspension.
After suspension for bleeding or frailty, patients remain at high‐risk of death or complications.
Summary
Background
Anticoagulation in elderly patients with non‐valvular atrial fibrillation (NVAF) is still a challenge, and discontinuation of warfarin is common. The aim of this study was to analyze the aspects related to warfarin discontinuation in a real‐world population.
Methods
This was an observational cohort study on very elderly NVAF patients naive to warfarin therapy (VENPAF). The included subjects were aged at least 80 years, and started using warfarin after a diagnosis of NVAF. Warfarin discontinuation was assessed, and the reason reported for discontinuation, the person who decided to stop treatment, subsequent antithrombotic therapy and mortality, ischemic and bleeding events were collected.
Results
Over a period of 5 years, warfarin was discontinued in 148 of 798 patients. Despite similar CHA2DS2‐VASc scores, the frequencies of thromboembolic and major bleeding events were significantly higher (P = 0.01 and P = 0.001, respectively) and the time in therapeutic range (TTR) was significantly lower (P < 0.001) in patients who discontinued warfarin. Independent risk factors for warfarin discontinuation were vascular disease (hazard ratio [HR] 2.5, P < 0.001), age ≥ 85 years (HR 1.4, P = 0.04), TTR < 60% (HR 1.8, P = 0.001), and bleeding events (HR 2.3, P < 0.001). The main reasons for warfarin discontinuation were physician‐perceived frailty or low life‐expectancy (45.9%), bleeding complications (19.6%), and sinus rhythm restoration (16.9%). Event and death rates were very high, especially in frail patients and in those with bleeding complications.
Conclusions
Warfarin discontinuation is frequent in very elderly patients, and is associated with increased risks of death and adverse events. Identification of elderly patients who are at high risk of bleeding and the poor quality of anticoagulation during warfarin are still unsolved clinical problems.