Occurrence of Bleeding and Thrombosis During Antiplatelet Therapy in Non-cardiac Surgery (OBTAIN)
- What is the absolute risk reduction for in-hospital major adverse cardiac events (MACE) associated with the use of dual anti-platelet therapy as compared with aspirin alone in this population?
- What is the absolute risk increase for clinically significant bleeding during the same period associated with the use of dual anti-platelet therapy as compared with aspirin alone in this population?
In brief the design of the study is as follows:
- We will study patients undergoing non-cardiac surgery within four years of coronary stenting.
- We will record the anti-platelet agents taken by patients before, during and after surgery.
- We will record cardiac and bleeding events that occur whilst the patient is in hospital.
- We will use the statistical technique of propensity scoring to match patients who have similar risk factors and who received different anti-platelet regimens.
- We will compare the incidence of cardiac events and bleeding in the matched groups.
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Occurrence of Bleeding and Thrombosis During Antiplatelet Therapy in Non-cardiac Surgery. A Prospective Observational Study (OBTAIN Study)|
- 1. MACE [ Time Frame: In-hospital stay up to 30 days ] [ Designated as safety issue: No ]
This study will record and analyse in-hospital adverse cardiac events. Major Adverse Cardiac Events (MACE) will be defined as a composite of:
- Myocardial infarction as defined by the Universal Definition of Myocardial Infarction(including cardiac arrest and cardiac death as described in this definition).
- PCI for a cardiac event occurring following surgery.
- 2. Clinically significant bleeding [ Time Frame: In-hospital stay up to 30 days ] [ Designated as safety issue: No ]
This study will record and analyse in-hospital clinically significant bleeding.
Clinically Significant Bleeding Events will be defined as:
- Reoperation for bleeding.
- Gastrointestinal haemorrhage
- Intracranial haemorrhage
- Spinal/epidural haematoma. The transfusion of blood and blood products will also be recorded and compared between patients on dual antiplatelet therapy and aspirin alone.
|Study Start Date:||October 2011|
|Study Completion Date:||January 2014|
|Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
This study will compare the use of aspirin alone with dual antiplatelet therapy (i.e. aspirin and clopidogrel) in patients presenting for elective non-cardiac surgery who have undergone PCI with either bare metal stent or drug eluting stent placement in the four years prior to surgery. The absolute risk reduction in major adverse cardiac events (MACE) with dual antiplatelet therapy and the absolute risk increase for clinically significant bleeding events with dual therapy will be determined. This will allow the number needed to treat (NNT) for the prevention of MACE and the number needed to harm (NNH) for bleeding to be determined and the optimal antiplatelet therapy in this setting to be identified.
|University Hospital Carl Gustav Carus|
|Dresden, Germany, 01307|
|University of Leeds, Sectional of Translational Anaesthetic and Surgical Sciences|
|Leeds, United Kingdom, LS9 7TF|
|Study Chair:||Simon Howell, MD||Sectional of Translational Anaesthetic and Surgical Sciences, University of Leeds, United Kingdom|