Table 2 Subgroup analyses of all-cause mortality
SubgroupNumber of studiesPooled HR95% CIsHeterogeneity across studies
Sample sizes
  ≥40032.111.07–4.15P<0.001; I2 = 88.2%;
  <40062.491.64–3.79P=0.011; I2 = 66.2%
Follow-up duration
  >1.5 years31.441.04–1.99P=0.109; I2 = 54.8%
  <1.5 years62.972.33–3.78P=0.387; I2 = 4.6%
Region
  Europe62.461.49–4.05P<0.001; I2 = 82.3%
  Others32.391.80–3.17P=0.654; I2 = 0.0%
Cys-C cut-off value
  Single category62.111.39–3.21P<0.001; I2 = 77.9%
  ≥3 category32.821.76–4.53P=0.151; I2 = 47.1%
Types of HF
  Chronic HF12.151.30–3.55
  Acute HF72.391.63–3.50P<0.001; I2 = 78.0%