A novel enoxaparin regime for ST elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: A WEST sub-study
ABSTRACT To evaluate the anticoagulation effect of subcutaneous (SQ) and intravenous (IV) enoxaparin through systematic anti-Xa sampling during primary PCI for acute STEMI.
Although appropriate anticoagulation is essential to maximize the efficacy and safety of primary PCI, the optimal dosing of enoxaparin in this setting is unclear.
STEMI patients randomized to primary PCI received ASA, clopidogrel 300 mg and enoxaparin 1 mg/kg SQ at earliest point of care, including prehospital. Plasma anti-Xa determination occurred just prior to and after primary PCI. Supplemental IV enoxaparin (0.3-0.5 mg/kg) and abciximab was encouraged prior to PCI.
The 1st anti-Xa level 56 min (median, IQR 47-77) post SQ enoxaparin was 0.28 U/ml (0.23-0.41); 85% of patients (28/33) were <0.5 U/ml (the recommended therapeutic level). Following PCI, 126 min (118-185) after SQ enoxaparin in those without IV dosing (8/33) the 2nd anti-Xa level was 0.44 U/ml (0.29-0.53); 6 of 8 patients remained <0.5 U/ml. With IV enoxaparin (25/33) the 2nd anti-Xa was 0.96 U/ml (0.82-1.16) 97 min (82-109) after SQ enoxaparin: all were >or=0.5 U/ml and 2 had levels 1.5 U/ml.
A single SQ enoxaparin dose fails to achieve anti-Xa levels >or=0.5 U/ml in the majority of STEMI patients. When combined with a strategy of supplemental IV enoxaparin, adequate anti-Xa levels were achieved in all patients with few having levels >1.5 U/ml. This regime of SQ injection with additional IV enoxaparin provides an attractive strategy enhancing effective early anti-thrombotic therapy at first medical contact prior to primary PCI.
- SourceAvailable from: Kurt Huber
- [Show abstract] [Hide abstract]
ABSTRACT: Risk, the possibility of loss or injury, is indeed a fixture in all aspects of our lives, from investing in the stock market to crossing the street. This concept that we now take for granted is in fact relatively novel. Some have argued that the ability to describe, estimate and control risk is a key distinction between past and modern times.1 In early civilization, the future of human beings was largely thought to be at the whim of the gods. The turning point came during the Renaissance when Chevalier de Méré, a French nobleman with an affinity for gambling and mathematics, challenged the famed French mathematician Blaise Pascal to solve an infamous puzzle: How to divide the stakes of an unfinished game of chance between two players when one of them is ahead.1,2 Collaboration between Pascal and Pierre de Fermat, a lawyer and a talented mathematician, resulted in a solution and consequently, the theory of probability was born. And it is this concept that is at the heart of modern cardiovascular medicine and research.
- [Show abstract] [Hide abstract]
ABSTRACT: To investigate whether the beneficial and harmful effects of platelet glycoprotein IIb/IIIa receptor blockers in non-ST elevation acute coronary syndromes (NSTE-ACS) depend on age. A meta-analysis of six trials of platelet glycoprotein IIb/IIIa receptor blockers in patients with NSTE-ACS (PRISM, PRISM-PLUS, PARAGON-A, PURSUIT, PARAGON-B, GUSTO IV-ACS; n = 31 402) was performed. We applied multivariable logistic regression analyses to evaluate the drug effects on death or non-fatal myocardial infarction at 30 days, and on major bleeding, by age subgroups (<60, 60-69, 70-79, > or =80 years). We quantified the reduction of death or myocardial infarction as the number needed to treat (NNT), and the increase of major bleeding as the number needed to harm (NNH). Subgroups had 11 155 (35%), 9727 (31%), 8468 (27%) and 2049 (7%) patients, respectively. The relative benefit of platelet glycoprotein IIb/IIIa receptor blockers did not differ significantly (p = 0.5) between age subgroups (OR (95% CI) for death or myocardial infarction: 0.86 (0.74 to 0.99), 0.90 (0.80 to 1.02), 0.97 (0.86 to 1.10), 0.90 (0.73 to 1.16); overall 0.91 (0.86 to 0.99). ORs for major bleeding were 1.9 (1.3 to 2.8), 1.9 (1.4 to 2.7), 1.6 (1.2 to 2.1) and 2.5 (1.5-4.1). Overall NNT was 105, and overall NNH was 90. The oldest patients had larger absolute increases in major bleeding, but also had the largest absolute reductions of death or myocardial infarction. Patients > or =80 years had half of the NNT and a third of the NNH of patients <60 years. In patients with NSTE-ACS, the relative reduction of death or non-fatal myocardial infarction with platelet glycoprotein IIb/IIIa receptor blockers was independent of patient age. Larger absolute outcome reductions were seen in older patients, but with a higher risk of major bleeding. Close monitoring of these patients is warranted.Heart (British Cardiac Society) 04/2007; 93(4):450-5. DOI:10.1136/hrt.2006.098657 · 5.60 Impact Factor