Anticoagulation with the low-molecular-weight heparin dalteparin (Fragmin®) in atrial fibrillation and TEE-guided cardioversion

Background Cardioversion (CV) in atrial fibrillation can cause arterial embolism. Effective anticoagulation clearly reduces the risk. In practice, in every third case anticoagulation is not in line with the recommendations. Simplification can be achieved, and time gained, by transesophageal echocardiography (TEE) due to the shorter anticoagulation period prior to CV, and by use of low-molecular-weight heparin (LMWH) for anticoagulation. As yet little data is available on LMWH in cardioversion. The aim of this cohort study was to investigate the administration of a LMWH in this indication under everyday clinical conditions. Methods 125 patients treated as inpatients for atrial fibrillation or -flutter received the LMWH Fragmin(R) (dalteparin 2 x 100 anti-Xa units/kg, maximum doasage 2 x 10 000 anti-Xa units subcutaneously). In the presence of a relevant indication, TEE-guided CV was performed. The application of dalteparin was terminated as soon as effective anticoagulation had been achieved from phenprocoumon or once anticoagulation was no longer indicated. Results 125 patients with atrial fibrillation or -flutter received dalteparin for a median of 11 days (range of 3-41 days). TEE was performed in 39 patients. Five patients revealed a thrombus in the left atrial appendage in the TEE, and one patient died from suspected cerebral embolism over the further course. In the remaining 124 patients, no thromboembolic event was established. Successfully cardioverted were 26 of 34 patients (76%) who had no thrombus in the TEE. Serious adverse effects did not ensue. Conclusion Simple, well-tolerated and effective anticoagulation is possible with dalteparin in TEE-guided CV. Due to the methodic limitations of a cohort study and the low incidence of emboli, the efficacy of dalteparin in this indication needs to be further confirmed by prospective and randomized studies.