Incidence of RR-NSVT
During the median follow up of 4.5 years (3.8-5.3 years), 68 (50.0%) out of 136 patients experienced at least 1 episode of RR-NSVT, and 34 patients (25.0%) experienced more than 3 episodes (Figure 1A). Of importance, whereas the accumulative incidence of ≥1 episode of RR-NSVT increased in a time-dependent manner, ≥2, ≥3 and ≥4 episodes of RR-NSVT showed a gradual increase before reaching a plateau. A similar tendency was observed in patients with primary (Figure 1B) and secondary prevention (Figure 1C).
In the RR-NSVT (+) group, cluster (≥ 3 times/6 months) and frequent (≥3 runs/day) RR-NSVT were noted in 42.6% (29/68) and 30.9% (21/68) of patients, respectively.