577 PACING LEADS THROMBOSIS IN CHILDREN AND YOUNG ADULTS WITH IMPLANTABLE ELECTRONIC DEVICES: OCCURRENCE OF A RARE COMPLICATION.


 
 
 Pacemakers (PMKs) and implantable cardioverter-defibrillators (ICDs) are frequently utilized in patients with specific cardiac rhythm disorders. The downfalls of these devices are several but no data exist regarding leads thrombosis.
 
 
 
 the analysis of pacing lead thrombosis occurrence in paediatric PMK-ICD patients.
 
 
 
 single Centre retrospective study of a series of paediatric/young adult patients showing pacing lead thrombosis. Data are reported as median (interquartile range).
 
 
 
 from 2015 to 2021 five patients (2 males), aged 16 (12-22) years, showed transthoracic echocardiographic evidence of lead vegetations during routine follow-up after 5 (1-16) years from lead's initial implantation. Age at device implantation was 9 (5-12) years. Two patients had dual-chamber ICD, 3 had PMKs (2 DDD, 1 VVI). No patient had any early wound complications after implantation. At the time of thrombosis detection, no patient reported any recent fever or symptoms of clinical illness. Devices and leads were normally functioning in all patients. Blood examination revealed absence of infectious or inflammatory signs, and all patients had negative hemocultures for aerobic, anaerobic bacteria and fungi. Therefore, lead thrombosis was diagnosed. Transesophageal echocardiogram (TEE) confirmed the echo finding. Thrombophilia testing revealed that 4 out of 5 patients had methylenetetrahydrofolate reductase (MTHFR) mutation, homozygous and heterozygous (2 each). Patients received oral anticoagulation therapy (OAT) and TEE showed complete recovery in 4 patients after 6-12 months; one adult patient is followed-up elsewhere.
 
 
 
 pacing lead thrombosis is a rare complication in paediatric/young adult patients with PMK/ICD, well treated with OAT. MTHFR mutation is a risk factor for this complication.
