Results
There were 6,219 leadless and 10,212 transvenous de novo implant procedures identified during the study period contributing to the analysis cohort (Table 1 ). Patient baseline characteristics of this cohort have been previously reported.3 Compared with transvenous, patients implanted with a leadless VVI pacemaker were more likely to have ESRD (12.0% vs. 2.3%, P<0.001), renal dysfunction (48.8% vs. 42.1%, P<0.001), and a higher mean Charlson Comorbidity Index score (5.1±3.4 vs. 4.6±3.0, P<0.001). Mean follow-up time for patients implanted with a leadless VVI pacemaker was 675 days, compared to 727 days for transvenous (P<0.001). After applying the propensity score overlap weights, all measured baseline and encounter characteristics were well balanced with all standardized mean differences near zero. There were 2,937 patients implanted with a leadless VVI pacemaker and 4,821 patients implanted with a transvenous VVI pacemaker in the sub-analysis of heart failure hospitalization endpoint analysis cohort without a prior history of heart failure.