Difficulty removing a leadless pacemaker in a post-transfusion patient

A 99-year-old woman with atrial fibrillation bradycardia and symptomatic long pauses underwent a leadless pacemaker implantation after red blood cell transfusion due to anaemia. The patient's blood tests after transfusion showed hypercoagulability; haematocrit, haemoglobin and fibrinogen levels were increased from 24.5% to 33.2%, 76 g/L to 111g/L, and 346 mg/dL to 646 mg/dL, respectively. Blood tests showed no hereditary hypercoagulability disorder and she had no history of thrombophilia. A leadless pacemaker was implanted in the correct position in the right ventricle. Heparin was administered after sheath insertion and the leadless pacemaker system was thoroughly flushed with heparinised saline before the tether was cut; however, removing the tether after leadless pacemaker implantation was difficult because clots had formed on the tether.