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DURHAM, N.C. -- The compelling urgency of coronary-bypass surgery before anticoagulant medication washes out must be weighed against increased bleeding risks and the potential benefits and economic impact of delaying surgery, said researchers here.
DURHAM, N.C., July 14 -- The compelling urgency of coronary-bypass surgery before anticoagulant medication washes out must be weighed against increased bleeding risks and the potential benefits and economic impact of delaying surgery, said researchers here.
The guidelines from the American College of Cardiology and the American Heart Association that recommend withholding anticoagulant therapy for at least five days before coronary artery bypass surgery (CABG) are often ignored, according to an observational study in the July 18 issue of the Journal of the American College of Cardiology, which was reported online.
When CABG was performed within that five-day window of halting Plavix (clopidogrel), bleeding risks among patients were 8% higher compared with those who delayed surgery for the recommended time, said Rajendra Mehta, M.D., of the Duke Clinical Research Institute, and colleagues.
In a study analyzing the patterns of Plavix use before CABG and the time-dependent risks of post-op transfusion, the researchers evaluated 2,858 patients with non-ST-segment elevation acute coronary syndromes having surgery at 264 hospitals participating in the CRUSADE National Quality Improvement Initiative.
CRUSADE stands for Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines.
In an analysis of outcomes for 852 patients (30%) who received Plavix within 24 hours of admission, nearly nine out of 10 (87%) of the Plavix patients had surgery within five days of the last drug treatment, the researchers reported.
These patients had an 8.1% increase in blood transfusions (65.0 % versus 56.9 %, adjusted odds ratio 1.36, 95% confidence interval 1.10 to 1.68), as well as the need for transfusion with at least four units of blood (27.7% vs. 18.4%, OR 1.70, CI 1.32 to 2.19).
In contrast, acute Plavix therapy was not associated with higher bleeding risks if surgery was delayed more than five days (adjusted OR 1.18, 95% CI 0.54 to 2.58).
Because patients receiving Plavix and early CABG were also more likely to be treated with a glycoprotein IIb/IIIa inhibitor, which can increase the risk for perioperative bleeding after early surgery, the researchers undertook several sensitivity analyses and found that the early-CABG patients continued to have a greater need for transfusions compared with an early-CABG-no Plavix group.
In analyzing the reasons for the early move to surgery, the researchers wrote:
"I think we are trying to show that common sense practice of medicine is more prudent and does not lead to increased risk in patients, despite what guidelines suggest," Dr. Mehta said. "So all decisions? need to be made based on each patient's clinical characteristics, the expertise and ease of the operating surgeon in managing such patients, when they give informed consent."
In summing up the pros and cons of the study's findings, Dr. Mehta said that although the early-surgery patients were exposed to increased bleeding risks, this finding must be weighed against the clinical benefits of Plavix use as demonstrated in randomized clinical trials and the potential economic consequences of an extended hospital stay.
The authors pointed out several limitations of the study. The time between cardiac catheterization and CABG surgery was considered as a proxy for the time between the discontinuation of Plavix and CABG because the exact time of discontinuation of Plavix before CABG was not available. Actual hemoglobin values that led to transfusions were not collected.
Dr. Mehta reported receiving speaker fees from Bristol-Myers Squibb. CRUSADE is funded by Millennium Pharmaceuticals and Schering. Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership (the makers of Plavix) provided additional funding.