Heart Failure Hospitalizations and All-Cause Mortality
Heart failure hospitalization rates were slightly lower among patients
implanted with a leadless VVI pacemaker compared to transvenous in the
overall patient cohort (adjusted, 19.9% vs. 22.0%, P=0.005) as well as
among patients without prior history of heart failure (adjusted, 11.2%
vs. 13.6%), P=0.003) (Appendix Table 4 ). In the time-to-event
models, patients with a leadless pacemaker had a slightly, but
significantly lower, rate of heart failure hospitalization compared with
patients implanted with a transvenous pacemaker through 3 years
(Figure 1C ; unadjusted HR 0.90; 95% CI 0.84–0.97, P=0.006;
adjusted HR 0.90; 95% CI 0.83–0.97, P=0.005). Among patients without
history of heart failure, the lower rates among patients implanted with
a leadless VVI pacemaker were more pronounced (unadjusted HR 0.83; 95%
CI 0.72–0.94, P=0.005; adjusted HR 0.81; 95% CI 0.71–0.93, P=0.003)
(Appendix Figure 2 ).
The unadjusted 3-year all-cause mortality rate was significantly greater
in the patients implanted with a leadless VVI pacemaker compared with
the transvenous (HR, 1.09; 95% CI, 1.03-1.15, P=0.003); however, there
was no difference in the adjusted 3-year all-cause mortality rate
between leadless and transvenous (Figure 1D ; HR, 0.97; 95% CI,
0.92-1.03, P=0.32) after accounting for differences in baseline
characteristics.
For the composite endpoint of time to heart failure hospitalization or
death, there was no difference in the unadjusted rates for either the
full cohort or those patients without history of heart failure (full
cohort: unadjusted HR 1.03; 95% CI 0.98-0.1.08, P=0.28; sub-cohort:
unadjusted HR 1.00, 95% CI 0.93-1.08, P=0.98). After statistical
adjustment, there were small differences, with patients implanted with a
leadless VVI pacemaker having slightly lower rates than transvenous
(full cohort: adjusted HR 0.94; 95% CI 0.89-0.99, P=0.01; sub-cohort:
adjusted HR 0.92, 95% CI 0.85-0.99, P=0.03) (Appendix Figures
3A and 3B ).