Page 84 - Biomarkers for risk stratification and guidance in heart failure

Which heart failure patients profit from natriuretic peptide-guided therapy?
We used the same cut-off to distinguish HFrEF from HFpEF (i.e. LVEF of 45%), as in the previous analysis, which was based on the cut-off used in the majority of the trials.1 Using cut-offs of 40% or 50% did not change results significantly and are therefore not presented.
Statistical analysis
Data are presented as frequencies, mean ± standard deviation (SD) or median
(interquartile range, IQR), as appropriate. Comparisons of baseline characteristics
using -test for categorical data and one-way ANOVA or Kruskal - Wallis H-test for continuous data, as appropriate.
The pre-specified primary endpoint was all-cause mortality. Secondary
endpoints encompassed time to first HF admission and the combined endpoint 4 of HF hospitalization or death. We analysed time-to-event for assessing outcome
by using unadjusted Cox proportional hazards regression models. Effect of
treatment strategy allocation on outcome in HFpEF and HFrEF patients was
visualized by Kaplan - Meier analysis. After analysis of potential differences in the
treatment effect between HFrEF and HFpEF in all patients, further analyses were
performed for HFpEF and HFrEF separately. Heterogeneity between studies was
tested by treatment × study interaction effect across studies. Cox proportional
hazard regression models were used to test the influence of comorbidities on
treatment response in both HFpEF and HFrEF. Furthermore, interaction between
treatment strategy allocation and comorbidities on outcome was assessed by incorporating comorbidities × treatment as terms in the Cox regression model.
All analyses were performed using IBM SPSS Statistics version 21.0 apart from
aggregated hazard ratios (HR), which were calculated using Review Manager 5.2
(Nordic Cochrane Centre, Copenhagen, Denmark).
RESULTS
The baseline characteristics of the patients participating in the eight trials included in this analysis are depicted in Table 1. The patients were on average elderly, one-third were female and comorbidities were frequent.
There were significant differences in patients’ characteristics between the studies (P < 0.05 for all), as shown in detail in Table 1. In addition, not all studies
between the different studies and between HFpEF and HFrEF were performed 2
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