Abstract Background Pocket hematoma (PH) is one of the most common complications after cardiovascular implantable electronic device (CIED) implantation resulting in an up to 9 times higher risk for CIED infections.(1) Different preventive strategies have been proposed with mixed results. Current standard of care consists of preventive elastic adhesive tape leaving 2 major disadvantages: unpredictable pressure on the pocket and inability to visually assess the pocket with the bandage applied. Aim To evaluate the safety and effectiveness of a novel pocket compression device in patients undergoing CIED implantation in a high bleeding population. Material and methods This randomized controlled trial included 32 patients in the study group (pocket compression device) and 33 in the control group (elastic adhesive tape). The studied pocket compression device contains an inflatable compartment to modify the degree of pocket compression which is transparent facilitating pocket evaluation. The primary outcome was the incidence of various grades of PH. The secondary outcomes comprised the incidence of pressure lesion, pain score (0-10) and endocarditis during follow-up. Results There were no clinical or procedural differences between groups (age 78.01±9.71, heart failure 53.8%, kidney failure 20.0% and on antithrombotic drugs 49.2%). There were significantly less pocket hematomas in the study group (1/32 (3.1%) vs 20/33 (60.6%), P<0.001). Most pocket hematomas were grade I for which watchful waiting was applied (1/32 (3.1%) vs 17/33 (51.6%), P<0.001). Grade II and grade III PH only occurred in the control group (respectively 1/33 and 2/33) resulting in hospitalization prolongation and longer interruption of antithrombotic drugs >24hours. Two control patients eventually received the study device to control PH. None underwent reoperation. Pressure lesions did not occur. Patients in the study group had lower pain scores at application (0.75±1.12 vs 1.80±1.38, P=0.009), after 2 hours (0.81±1.36 vs 1.94±1.50, P=0.002) and the next day (0.38±0.91 vs 1.06±1.634, P=0.042). None of the patients experienced endocarditis during mean follow-up of 1 year. Conclusion The use of a pocket compression device in patients undergoing CIED implantation in a high bleeding population leads to less PH and postoperative pain in comparison to conventional elastic adhesive tape.bandage study