Gastrointestinal haemorrhage in atrial fibrillation patients: impact of quality of anticoagulation control

Abstract

BACKGROUND: Gastrointestinal haemorrhage is a known complication of antiplatelet and anticoagulation therapy. Little is known about the impact of warfarin of different time in therapeutic range (TTR) on the risk of gastrointestinal haemorrhage in atrial fibrillation (AF) patients compared to aspirin. METHODS: This was an observational study. RESULTS: We studied 5426 Chinese AF patients (77.7 ± 10.7 years; female: 53.1%) with CHA2DS2-VASc score of ≥1—3832 (70.6%) patients were taking aspirin, 1594 (29.4%) patients were taking warfarin, while the remaining patients did not receive any anticoagulation. The mean baseline HAS-BLED score (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) was 2.22 ± 0.93. Among those on warfarin, the median TTR was 39.2%. After a mean follow-up of 3.6 years (19 777 patient-years), 262 (4.83%) patients developed gastrointestinal haemorrhage requiring transfusion with an annual incidence of 1.32%. Annual incidences of gastrointestinal haemorrhage requiring transfusion among patients on aspirin and warfarin were 1.53% and 1.00%, respectively. For patients on warfarin, the incidence of gastrointestinal haemorrhage increased progressively with higher HAS-BLED scores, from 0.93% per year for those with HAS-BLED score of ≤1 to 1.68% per year for those with HAS-BLED score of ≥3, and decreased progressively with increasing TTR from 1.69% per year for patients in the lowest quartile of TTR to only 0.51% per year for those in the top quartile. CONCLUSION: Overall, aspirin was associated with a higher risk of gastrointestinal bleeding compared with warfarin despite the suboptimal TTR in the study population. For patients on warfarin, HAS-BLED score at baseline prior to commencing anticoagulation positively correlated with gastrointestinal bleeding. Poor TTR was associated with a higher risk of gastrointestinal bleeding