Prehospital administration of enoxaparin before primary angioplasty for ST‐elevation acute myocardial infarction

Abstract

We hypothesized that primary percutaneous coronary intervention (PCI) could be performed with prehospital injections of enoxaparin for ST segment elevation myocardial infarction (STEMI). Enoxaparin has been studied in combination with fibrinolysis in STEMI, but has not been evaluated as anticoagulant regimen for primary PCI. In a prospective registry, 143 consecutive patients with STEMI received prehospital 0.5 mg/kg intravenous (i.v.) bolus followed by 1 mg/kg subcutaneous enoxaparin before immediate transport for PCI. We focused on anti-Xa activities before and after PCI, bleedings, infarct-related artery patency, and major adverse cardiac events at day 30. Anti-Xa activity was at the target level (>0.5 IU/ml) in 99% of patients during PCI, and in 100% 4 hr after injections; over-anticoagulation (>1.5 IU/ml) was noted in 9 and 2%, respectively at start and 4 hr after injections. Bleeding complications with enoxaparin were rare: major in 1.4% (no intracranial hemorrhages), minor in 2.1%. A patent infarct-related artery (TIMI 2 + 3) was observed in 40.6% of the patients before PCI. TIMI 3 flow was obtained in 88.1% of the cases after PCI. Major adverse cardiac events at 30 days occurred in 5.6% of cases: death 2.8%, reinfarction 3.5%, and target lesion revascularisation 3.5%. Prehospital i.v. and subcutaneous enoxaparin provides simple and rapid anticoagulation for PCI in STEMI patients. Enoxaparin dose needs to be reduced regarding the 9% of over-anticoagulation. This study suggests the potential of enoxaparin as an alternative anticoagulant regimen for primary PCI.

Effects of the Early Administration of Heparin in Patients With ST-Elevation Myocardial Infarction Treated by Primary Angioplasty

“…10 In the present study, sufficient time (144 min) was allowed for heparin to affect IRA patency. Moreover, the proportion of patients transferred from other hospitals was relatively small (29%), and thus avoids selection bias from the route of admission, as was supported by our subgroup analysis of non-referred patients.…”

“…[7][8][9][10] Of these 3 patients, 2 who had been treated with abciximab experienced profuse bleeding in the oral cavity or at a tracheostomy site, and both required a massive blood transfusion after PCI, but finally succumbed to hypovolemic shock. The other patient, who had not been treated with abciximab, developed retroperitoneal hematoma and recovered from transient hypovolemic shock after a blood transfusion.…”

“…5,6 However, the role of adjunctive heparin in patients treated with primary PCI is not well established, with the few previous studies showing variable results. [7][8][9][10] Therefore, we investigated the effect of the early administration of heparin in the emergency room (ER) on both initial infarct-related artery (IRA) patency and clinical outcome in patients with STEMI treated by primary PCI.…”

Part 9: Acute Coronary Syndromes

“…Three studies of PCI after fibrinolysis resulted in favorable outcome when enoxaparin was compared with UFH (LOE 4 397,432 ; LOE 5 394 ). Eight other studies showed no benefit using enoxaparin compared with UFH (LOE 2 342,433,434 ; LOE 4 405,409,435,436 ; LOE 5 345 ).…”

Eficacia y seguridad de la enoxaparina en la angioplastia primaria. Análisis comparativo con la heparina no fraccionada

“…De hecho, el estudio fue diseñado sin suplementos intravenosos de enoxaparina, pero se produjeron tres trombosis de catéter en el grupo inicial, y se cambió la pauta de tratamiento a suplementos intravenosos. Labèque et al 13 también han estudiado la administración prehospitalaria de ENX antes de la AP en el IAMCEST. Ese grupo administró un bolo intravenoso de 0,5 mg/kg, seguido de 1 mg/kg subcutáneo, a nivel prehospitalario antes de la AP.…”