Baldinger, Samuel HannesSamuel HannesBaldinger0000-0002-2296-4631Burren, DésiréeDésiréeBurrenNoti, FabianFabianNotiServatius, Helge SimonHelge SimonServatiusSeiler, JensJensSeilerMadaffari, AntonioAntonioMadaffariAsatryan, BabkenBabkenAsatryan0000-0002-0050-5717Tanner, HildegardHildegardTannerReichlin, Tobias RomanTobias RomanReichlin0000-0002-7197-8415Häberlin, Andreas David HeinrichAndreas David HeinrichHäberlin0000-0002-9283-0110Roten, LaurentLaurentRoten0000-0002-0827-13292025-01-082025-01-082024-06https://boris-portal.unibe.ch/handle/20.500.12422/202569AIMS Pacemaker (PM) patients may require a subsequent upgrade to an implantable cardioverter defibrillator (ICD). Limited data exists on this patient population. We sought to characterize this population, to assess predictors for ICD upgrade, and to report the outcome. METHODS From our prospective PM and ICD implantation registry, all patients who underwent PM and/or ICD implantations at our center were analyzed. Patient characteristics and outcomes of PM patients with subsequent ICD upgrade were compared to age- and sex-matched patients with de novo ICD implantation, and to PM patients without subsequent upgrade. RESULTS Of 1'301 ICD implantations, 60 (5%) were upgraded from PMs. Median time from PM implantation to ICD upgrade was 2.6 years (IQR 1.3-5.4). Of 2'195 PM patients, 28 patients underwent subsequent ICD upgrades, corresponding to an estimated annual incidence of an ICD upgrade of at least 0.33%. Lower LVEF (p = .05) and male sex (p = .038) were independent predictors for ICD upgrade. Survival without death, transplant and LVAD implantation were worse both for upgraded ICD patients compared to matched patients with de novo ICD implantation (p = .05), as well as for PM patients with subsequent upgrade compared to matched PM patients not requiring an upgrade (p = .036). CONCLUSIONS One of 20 ICD implantations are upgrade of patients with a PM. At least one of 30 PM patients will require an ICD upgrade in the following 10 years. Predictors for ICD upgrade are male sex and lower LVEF at PM implantation. Upgraded patients have worse outcomes.enimplantable cardioverter defibrillator mortality pacemaker risk factors upgrade600 - Technology::610 - Medicine & healtharticle10.48350/1962113865561010.1111/pace.14988