Clopidogrel

Using triple antiplatelet therapy in patients with non-ST elevation acute coronary syndrome managed invasively: a cost-effectiveness analysis

OBJECTIVES

To assess the incremental cost-effectiveness ratio (ICER) of glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) pretreated with aspirin and clopidogrel undergoing an early invasive treatment strategy.

METHODS

Cost-effectiveness analysis and cost-utility analysis were performed from a health-care system perspective, based on a Markov model with a time horizon of the patient life span. The risk of death and ischemic events was assessed using the Thrombolysis in Myocardial Infarction (TIMI) risk score. We compared three strategies: 1) routine upstream use of a GPIIb/IIIa inhibitor to all patients before angiography, 2) deferred selective use of abciximab in the catheterization laboratory just before angioplasty, and 3) double antiplatelet therapy without GPIIb/IIIa inhibitors. Both univariate sensitivity analysis and second-order probabilistic microsimulation were performed.

RESULTS

In the base case (65 years old, TIMI score 3), strategy A was the most effective, with an ICER of 15,150 euros per quality-adjusted life-year gained. Strategy B was dominated by a combination of strategies A and C. The ICER was very sensitive to the age and baseline risk of the patient. According to the widely accepted cost-effectiveness thresholds, strategy A would be cost-effective only in patients with an intermediate to high TIMI score, especially within the younger age groups. The probability that strategy A was cost-effective under the base case was 91.2%.

CONCLUSIONS

The use of GPIIb/IIIa inhibitors upstream in high-risk NSTE-ACS patients (TIMI score > or = 3) pretreated with aspirin and clopidogrel is cost-effective, particularly in the younger age groups.

P2Y1 receptor antagonists as novel antithrombotic agents

The P2Y(1) and P2Y(12) purinergic receptors are responsible for mediating adenosine diphosphate (ADP) dependent platelet aggregation. Evidence from P2Y(1) knockout studies as well as from nucleotide-based small molecule P2Y(1) antagonists has suggested that the antagonism of this receptor may offer a novel and effective method for the treatment of thrombotic disorders. Herein, we report the identification and optimization of a series of non-nucleotide P2Y(1) antagonists that are potent and orally bioavailable.

Effects of a waiting period after clopidogrel treatment before performing coronary artery bypass grafting

STUDY OBJECTIVE

To assess the effects of a waiting period after clopidogrel treatment before coronary artery bypass grafting (CABG). Design. Single-center, prospective, observational study.

SETTING

Cardiothoracic surgery intensive care unit at a university-affiliated medical center.

PATIENTS

One hundred consecutive patients who received clopidogrel and were scheduled to undergo primary CABG. In 64 of these patients, CABG was delayed at least 5 days after clopidogrel treatment (group A). The other 36 patients received clopidogrel treatment within 5 days of undergoing CABG (group B).

MEASUREMENTS AND MAIN RESULTS

Data were collected on patient demographics, time of last clopidogrel dose, preoperative anticoagulant and/or antiplatelet agents administered, surgical characteristics, intraoperative transfusions, blood products transfused, and chest tube output for 24 hours after surgery. No significant differences in baseline characteristics or intraoperative variables (number of bypasses, aortic cross-clamp time, and cardiopulmonary bypass time) were noted between the two groups. Mean +/- SD number of packed red blood cell units/patient was 1.1 +/- 1.4 in group A versus 2.1 +/- 2.5 in group B (p=0.009). Mean +/- SD number of platelet units/patient transfused was 0.5 +/- 0.9 in group A versus 1.9 +/- 1.6 in group B (p<0.001). When comparing a subset of 21 patients who received clopidogrel within 72 hours of surgery with the 64 whose CABG was delayed at least 5 days after clopidogrel treatment, the transfusion rates were significantly higher (95% vs 52%, p<0.05). Specifically, the mean +/- SD number of transfused units/patient of red blood cells (3.1 +/- 2.8 vs 1.1 +/- 1.4, p<0.005) and platelets (2.6 +/- 1.5 vs 0.5 +/- 0.9, p<0.007) was greater in patients who received clopidogrel within 72 hours of surgery.

CONCLUSION

A strategy to delay CABG after clopidogrel treatment led to reduced blood product administration. The optimal waiting period after clopidogrel treatment is not known but appears to be at least 5 days before CABG.