Effectiveness by gender and age of renin‐angiotensin system blockade in heart failure—A national register‐based cohort study

PURPOSE: Investigate effectiveness by gender and age and equity implications of treatment with renin‐angiotensin system blockade (RASb) in heart failure (HF) patients. METHODS: In this population‐based register study, we used inpatient data from 2006 to 2010 for patients age 20 years or older with no HF hospitalisation for minimum of 1 year before an index hospitalisation. A wash‐out period for RASb of 6 months preceding admission was used. Hospital data were linked with drug dispensation data and cause of death data. The associations between time‐dependent RASb exposure and all‐cause death and HF death, respectively, were examined by Cox regression models. Interactions by gender and age were also investigated on the multiplicative and additive scales. RESULTS: Thirty thousand seven hundred twenty‐one patients were analysed. Fifty‐one percent were women. Median age was 83. Fifty‐three percent of women and 64% of men received RASb after the index hospitalisation. Younger patients were more likely to receive RASb than older ones. One‐year mortality was 28%. RASb was associated with an overall hazard ratio (HR) for all‐cause death of 0.72 (95% confidence interval 0.69‐0.75), and an HR of 0.85 (0.77‐0.93) for HF death. Interaction analyses showed HRs for all‐cause death associated with RASb between 0.12 (0.10‐0.13) in the youngest, and 0.80 (0.76‐0.84) in the oldest patients. CONCLUSIONS: RASb appeared effective for women and men and for patients of all ages in this hospitalised HF cohort. No gender difference in effectiveness was found. RASb exposure was low overall, indicating a need for improved adherence to treatment guidelines. Treatment with RASb may be inequitable for women and older patients.