Abstract 14849: Impact of Intravenous Heparin Bolus on Outcomes of Leadless Pacemaker Implantation

Abstract

Background: During Micra leadless pacemaker (LP) implantation, continuous heparin is infused to prevent thrombus within the sheath and on the device. Early guidance from the manufacturer (Medtronic) recommended an initial systemic heparin bolus to further prevent thrombus formation. However, systemic heparin may increase the risk of implant complications. Thus, many operators have moved away from routine boluses. However, there is a paucity of data on the impact of heparin bolus on outcomes. Methods: We reviewed all Medtronic Micra LP implants at our institution from 9/2014 to 9/2022. The decision to bolus with heparin was at the operator discretion. Results: Among 621 LP implants, 326 received a heparin bolus, 243 did not, and 52 patients had unknown bolus status. In the cohort, 50.4% were men. Mean age at implant was 76.8 ± 14.9 years. Mean follow up was 1.7 ± 1.4 years. There were no significant differences in device electrical parameters (R wave sensing, impedance, and capture thresholds), right ventricular pacing burden (RVP), or left ventricular ejection fraction (LVEF) comparing heparin bolus vs. no bolus at both initial interrogation and long-term follow up (Figure). There was no difference between groups in the number of attempted device deployments per implant procedure (1.42 ± 0.81 vs 1.31 ± 0.66, p=0.15). Implant-related adverse events were also similar between bolus and no-bolus groups: access-site hematoma (5 vs 7, p=0.99), pseudoaneurysm (1 vs 1, p=0.99), cardiac perforation (1 vs 1, p=0.99), 30-day re-hospitalization (15 vs 21, p=0.98) and 30-day all-cause mortality (14 vs 16, p=0.57). There was 1 additional non-fatal cardiac perforation in a patient with unknown bolus status. Conclusion: Routine systemic bolus of heparin can be safely omitted in appropriately selected patients undergoing LP implant. Heparin bolus may still be considered in long cases requiring multiple device deployments or in patients with high risk for thrombotic complications.