Secondary outcome: all-cause mortality in specific population
In patients with ICM, CRT-D was associated with a lower all-cause mortality risk compared with CRT-P (HR: 0.74, 95%CI: 0.64-0.86, I2=0%, P<0.0001) (Figure 4A). However, this benefit of CRT-D was not confirmed in patients with non-ischemic cardiomyopathy (HR: 0.91, 95%CI: 0.82-1.01, I2=0%, P=0.087) (Figure 4B). In the elderly (age≥75 years), CRT-D recipients had similar all-cause mortality compared to CRT-P recipients (HR: 0.96, 95%CI: 0.83-1.12, I2=0%, P=0.61) (Figure 4C).Moreover, for patients receiving CRT-D, there was no significant benefits in all-cause mortality compared to CRT-P group regardless of male (HR: 0.83, 95%CI: 0.65-1.07, I2=77.8%, P=0.151) (Supplementary Figure 1) and female (HR: 0.87, 95%CI: 0.54-1.39, I2=76.5%, P=0.560) (Supplementary Figure 2). Due to high heterogeneity and unstable of results by sensitivity analysis, we cannot draw a conclusion easily in association of gender and device type.