What does routinely-collected electronic health record data tell us about the use of heart failure medication among older people in Wales? Making progress but could do better

Abstract Background European Society of Cardiology 2021 guidelines recommend 4 pillars of treatment to reduce mortality for those with heart failure (HF) and reduced ejection fraction (HFrEF): pillar 1) angiotensin converting enzyme inhibitor (ACE-I)/angiotensin receptor blocker (ARB)/angiotensin receptor-neprilysin inhibitor (ARNI), pillar 2) beta-blocker (BB), pillar 3) mineralocorticoid receptor antagonist (MRA), pillar 4) sodium-glucose co-transporter 2 inhibitor (SGLT2i). When there is heart failure with preserved ejection fraction (HFpEF), guidelines recommend diuretics to alleviate congestion and treatment of risk factors such as hypertension and diabetes. Prior to 2021, United Kingdom guidelines did not include SGLT2i. Purpose To examine how HF treatment is recorded in routinely-collected electronic health record (EHR) data for older people in Wales, and to explore how that has changed since 2015. Methods We conducted a retrospective, population-level, observational study using linked anonymised EHR data in Wales (2015-22). 737,230 individuals were aged 65y+ in the study period (21.5% of population in 2022). Of these, 65,010 had a code for heart failure in their primary or secondary care records. We excluded 13,990 individuals with fewer than 12 months data pre- or post-diagnosis. We looked forward, from HF diagnosis, for codes associated with specific medications. Results The final cohort comprised 51,020 individuals aged 65y and over with a diagnosis of heart failure between 2015-2022. Incidence and prevalence of heart failure increased across the study period (1.4-1.5% and 8.5-9.1% respectively). Preceding cardiovascular diagnoses included hypertension (69.5%), atrial fibrillation (36.7%), myocardial infarction (30.5%), coronary artery disease (25.7%), and valve disease (17.7%). Diabetes (41.7%), chronic kidney disease (30.9%) and cancer (26.4%) were the most common comorbidities. The subtype of HF (HFrEF or HFpEF) was only evident in 5,850. Treatments recorded most often were loop diuretics, ACE-I, and BB (Table 1). SGLT2i codes increased in 2020/2021(Figure 1). At 10-12 months post diagnosis, the proportion with simultaneous pillar combinations was; 27.4% 1 + 2, 12.5% 1, 2 + 3, and only 2% 1, 2, 3 + 4. Conclusions In Wales, there is a need to improve the coding of HF subtype in primary care records. We suggest interpreting data with the assumption that approximately half of the cohort are likely to have HFrEF. While the cohort proportion on ACE-I or beta-blockers may be appropriate, the proportion with more than 1 simultaneous pillar of treatment recorded appears low. The use of SGLT2i in codes is increasing. These results are important in evaluating health service delivery and in establishing baseline data from which to monitor improvements.