TY - DATA T1 - Clinical manifestations and outcomes of severe warfarin overanticoagulation: from the EWA study PY - 2017/11/23 AU - Samuli Jaakkola AU - Ilpo Nuotio AU - Tuomas O. Kiviniemi AU - Raine Virtanen AU - Aku Virta AU - K. E. Juhani Airaksinen UR - https://tandf.figshare.com/articles/journal_contribution/Clinical_manifestations_and_outcomes_of_severe_warfarin_overanticoagulation_from_the_EWA_study/5629780 DO - 10.6084/m9.figshare.5629780.v1 L4 - https://ndownloader.figshare.com/files/9802894 KW - Atrial fibrillation KW - anticoagulation KW - bleed KW - complication KW - warfarin N2 - Introduction: Severe warfarin overanticoagulation is a risk factor for bleeding, but there is little information on its manifestations, prognosis and factors affecting the outcome. We describe the manifestations and clinical outcomes of severe warfarin overanticoagulation in a large group of patients with atrial fibrillation (AF). Material and methods: All international normalized ratio (INR) samples (n = 961,431) in the Turku University Hospital region between 2003 and 2015 were screened. A total of 412 AF patients with INR ≥9 were compared to 405 patients with stable warfarin anticoagulation for AF. Electronic patient records were manually reviewed to collect comprehensive data. Results: Of the 412 patients with INR ≥9, bleeding was the primary manifestation in 105 (25.5%). Non-bleeding symptoms were recorded in 165 (40.0%) patients and 142 (34.5%) had no symptoms. A total of 17 (16.2%) patients with a bleed and 67 (21.8%) without bleeding died within 30 days after the event. Intracranial haemorrhage strongly predicted death within 30 days. Other significant predictors were non-bleeding symptoms, active malignancies, recent bleed, history of myocardial infarction, older age, renal dysfunction and a recent treatment episode. Conclusions: Bleeds are not the major determinant of the poor prognosis in severe overanticoagulation, as coincidental INR ≥9 findings also associate with high mortality.KEY MESSAGESOnly a quarter of AF patients with INR ≥9 suffered a bleeding event and the clinical manifestation of INR ≥9 had a significant impact on patient outcome.The 30-day mortality rate in patients with INR ≥9 was high ranging from 9.2 to 32.7%.Several significant predictors of 30-day mortality after INR ≥9 were identified. Only a quarter of AF patients with INR ≥9 suffered a bleeding event and the clinical manifestation of INR ≥9 had a significant impact on patient outcome. The 30-day mortality rate in patients with INR ≥9 was high ranging from 9.2 to 32.7%. Several significant predictors of 30-day mortality after INR ≥9 were identified. ER -