Primary endpoint
After a median duration of 49.0
(30.33-75.1) and 48.2(23.9-78.5) months’ follow-up in the CLBBB group
and in the Non-CLBBB group, the incidence of the composite primary
endpoint in the CLBBB group was significantly higher than the Non-CLBBB
group (21.4% vs. 6.5%, HR 3.98,
95%CI 1.64-9.64, P = 0.002) (Figure 1). As a component of the composite
primary endpoint, cardiovascular hospitalization was significantly
higher in the CLBBB group (14.3% vs.3.6%, HR 4.83, 95%CI 1.55-15.07,
P = 0.007). There were no significant differences in stroke and
all-cause mortality between the two groups (Table 2). All the death
cases in the two groups were due to cardiovascular causes.
In univariate regression analysis, QRS duration, heart failure, previous
stroke, COPD, and CLBBB were significantly associated with the
occurrence of the primary endpoint. After adjusting for these
variations, CLBBB (HR 2.92,
95%CI 1.17-1.34 P = 0.022) was the only independent risk factor for the
primary endpoint (Table 3).