Long-term Outcomes
A Kaplan-Meier analysis showed there was no significance difference in the composite outcome of hospitalizations from worsening heart failure and cardiovascular death among the three groups after the upgrade to CRT (p = 0.19). There were also no significant differences in cardiovascular death (p = 0.36) (Figure 4) . In group 1, however, the incidence of those adverse events tended to be lower than that in the other groups. No cardiovascular death occurred during the follow-up period in group 1. The mean recurrence-free period for the composite endpoint was longer in group 1 (2311 days, [95% CI; 1980–2642 days]) than group 2 (1989 days, [95% CI; 1494–2483 days]) and group 3 (1615 days, [95% CI; 1241 –1988 days]).