Thromb Haemost 2017; 117(10): 1930-1936
DOI: 10.1160/TH17-03-0162
Stroke, Systemic or Venous Thromboembolism
Schattauer GmbH

Derivation and validation of a novel bleeding risk score for elderly patients with venous thromboembolism on extended anticoagulation

Eva Seiler
1  Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland
,
Andreas Limacher
2  CTU Bern and Institute of Social and Preventive Medicine, University of Bern, Switzerland
,
Marie Méan
1  Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland
3  Department of General Internal Medicine, Lausanne University Hospital, Switzerland
,
Hans-Jürg Beer
4  Department of Internal Medicine, Cantonal Hospital of Baden, Switzerland
,
Joseph Osterwalder
5  Emergency Department, Cantonal Hospital of St. Gallen, Switzerland
,
Beat Frauchiger
6  Department of Internal Medicine, Cantonal Hospital of Frauenfeld, Switzerland
,
Marc Righini
7  Division of Angiology and Hemostasis, Geneva University Hospital, Switzerland
,
Markus Aschwanden
8  Department of Angiology, Basel University Hospital, Switzerland
,
Christian M. Matter
9  Cardiovascular Research, Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland
10  Department of Cardiology, University Heart Center, University Hospital Zurich, Switzerland
,
Martin Banyai
11  Division of Angiology, Cantonal Hospital of Lucerne, Switzerland
,
Nils Kucher
12  Division of Angiology, Inselspital, Bern University Hospital, University of Bern, Switzerland
,
Daniel Staub
8  Department of Angiology, Basel University Hospital, Switzerland
,
Bernhard Lämmle
13  University Clinic of Hematology and Central Hematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Switzerland
14  Center for Thrombosis and Hemostasis, University Medical Center, Mainz, Germany
,
Nicolas Rodondi
1  Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland
15  Institute of Primary Health Care (BIHAM), University of Bern, Switzerland; and
,
Alessandro Squizzato
16  Research Centre on Thromboembolic Disorders and Antithrombotic Therapies, Department of Clinical and Experimental Medicine, University of Insubria, Varese, Italy
,
Drahomir Aujesky
1  Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland
› Author Affiliations
Financial support: This study was supported by the Swiss Society of General Internal Medicine and the Swiss National Science Foundation (grant 33CSCO-122659/139470).
Further Information

Publication History

Received: 08 March 2017

Accepted after major revision: 16 June 2017

Publication Date:
09 November 2017 (online)

Summary

Existing clinical scores do not perform well in predicting bleeding in elderly patients with acute venous thromboembolism (VTE). We sought to derive an easy-to-use clinical score to help physicians identify elderly patients with VTE who are at high-risk of bleeding during extended anticoagulation (>3 months). Our derivation sample included 743 patients aged ≥65 years with VTE who were enrolled in a prospective multicenter cohort study. All patients received extended anticoagulation with vitamin K antagonists. We derived our score using competing risk regression, with the time to a first major bleeding up to 36 months of extended anticoagulation as the outcome, and 17 candidate variables as predictors. We used bootstrapping methods for internal validation. Sixty-six (9%) patients suffered major bleeding. The clinical score is based on seven clinical factors (previous bleeding, active cancer, low physical activity, anemia, thrombocytopenia, antiplatelet drugs/NSAIDs, and poor INR control). Overall, 48% of patients were classified as low-risk, 37% as moderate-risk, and 15% as high-risk of bleeding. The rate of major bleeding was 1.4 events in low-risk, 5.0 events in moderate-risk, and 12.2 events per 100 patientyears in high-risk patients. The c-statistic was 0.78 at 3 months and 0.71 at 36 months of extended anticoagulation. Model calibration was excellent (p=0.93). Internal validation showed similar results. This simple clinical score accurately identified elderly patients with VTE who are at high risk of major bleeding and who may not benefit from extended anticoagulation. Further validation of the score is important before its implementation into practice. The study is registered to https://clinicaltrials.gov as NCT00973596.

This work was carried out at the Department of General Internal Medicine in the Bern University Hospital, Switzerland.