Macroscopic thrombus formation on angioplasty equipment following antithrombin therapy with enoxaparin

Abstract

Increasing evidence suggests that treatment with the low molecular weight heparin enoxaparin during percutaneous coronary intervention (PCI) is safe and effective. We evaluated the incidence and consequences of periprocedural macroscopic thrombus formation on PCI equipment following antithrombin therapy with enoxaparin. Between April 2003 and December 2004, all patients undergoing cardiac catheterization following antithrombin therapy with enoxaparin were evaluated. All patients had blood sampled at the onset of procedure for subsequent measurement of anti-factor-Xa levels. Of the 4,504 patients who underwent PCI during this period, in 122 (3%) the procedure was performed within 8 hr of treatment with subcutaneous enoxaparin and no additional unfractionated heparin (UFH) was used periprocedurally. Of these, macroscopic thrombus was observed on PCI equipment in 6 patients (5%) necessitating withdrawal of all catheters and wires. All patients had therapeutic anti-factor-Xa levels at the time of PCI, and had been treated with double antiplatelet therapy with aspirin and clopidogrel. No periprocedural thrombus was observed in 356 patients who were >12 hr of the last dose of enoxaparin and received UFH at the time of PCI. Following observation of thrombus, additional anticoagulation with UFH resulted in significant epistaxis in one patient. In another patient, the procedure was complicated by distal coronary embolization. Percutaneous coronary intervention following antithrombin therapy with enoxaparin is associated with a 5% incidence of macroscopic thrombus formation on PCI equipment. The necessity for subsequent exchange of all equipment and/or the need for additional anticoagulation may have disastrous consequences for the patient. Our findings suggest that the safety of antithrombin therapy with low molecular weight heparin during PCI requires further evaluation.

Efficacy of enoxaparin, certoparin and dalteparin in preventing cardiac catheter thrombosis: an in vitro approach

“…As this aspect of anticoagulation during PCI is controversial-reports from recent clinical studies range from sufficient antiplatelet-only regimen without systemic anticoagulation for simple elective PCI [15] to a superiority of UFH over enoxaparin [16]-we sought to specifically focus on catheter thrombosis using an in vitro approach.…”

The direct thrombin inhibitor argatroban effectively prevents cardiac catheter thrombosis in vitro

“…Cardiac catheter thrombosis is a rare but potentially disastrous complication in the context of PCI (27). As this aspect of anticoagulation is highly controversial -reports from recent clinical studies range from sufficient antiplatelet-only regimen without systemic anticoagulation for simple elective PCI to a superiority of UFH over enoxaparin (28,29) -our group sought to focus in particular on catheter thrombosis using an in vitro approach. Having developed a sensitive model of cardiac catheter thrombosis we were able to reproduce, at the in vitro level, the higher incidence of catheter thrombosis following anticoagulation with fondaparinux initially reported from clinical trials (18).…”

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

“…Aún hoy, el fár-maco anticoagulante más eficaz en el laboratorio de hemodinámica es objeto de controversia, sobre todo en un escenario tan desfavorable por su ambiente trombótico, como la AP 10 . Dana et al 11 han informado recientemente del hallazgo de trombos macroscópi-cos en el material de angioplastia (catéteres y guías) en hasta un 5% de los pacientes a los que se realizó el procedimiento dentro de las 8 h de la última inyección subcutánea de ENX. Incluso encontraron trombo dentro del catéter guía en un paciente que sufrió una ICP de rescate por trombólisis fallida y que había sido tratado 2 h antes con bolo intravenoso y subcutáneo de ENX.…”