Abstract
AIMS: We aim to evaluate change in the use of prognostic guideline-directed medical therapies (GDMTs) for heart failure (HF) before and after a cancer diagnosis as well as the matched non-cancer controls, including renin-angiotensin-system inhibitors (RASIs), beta-blockers, and mineralocorticoid receptor antagonists (MRAs). METHODS AND RESULTS: We conducted a longitudinal study in patients with HF in the UK Clinical Practice Research Datalink between 2005 and 2021. We selected patients with probable HF with reduced ejection fraction (HFrEF) based on diagnostic and prescription records. We described the longitudinal trends in the use and dosing of GDMTs before and after receiving an incident cancer diagnosis. HF patients with cancer were matched with a 1:1 ratio to HF patients without cancer to investigate the association between cancer diagnosis and treatment adherence, persistence, initiation, and dose titration as odds ratios (ORs) with 95% confidence intervals (CIs) using multivariable logistic regression models. Of 8504 eligible HFrEF patients with incident cancer, 4890 were matched to controls without cancer. The mean age was 75.7 (±8.4) years and 73.9% were male. In the 12 months following a cancer diagnosis, patients experienced reductions in the use and dosing of GDMT. Compared with the non-cancer controls, patients with cancer had higher risks for poor adherence for all three medication classes (RASIs: OR = 1.51, 95% CI = 1.35-1.68; beta-blockers: OR = 1.22, 95% CI = 1.08-1.37; MRAs: OR = 1.31, 95% CI = 1.08-1.59) and poor persistence (RASIs: OR = 2.04, 95% CI = 1.75-2.37; beta-blockers: OR = 1.35, 95% CI = 1.12-1.63; MRAs: OR = 1.49, 95% CI = 1.16-1.93), and higher risks for dose down-titration for RASIs (OR = 1.69, 95% CI = 1.40-2.04) and beta-blockers (OR = 1.31, 95% CI = 1.05-1.62). Cancer diagnosis was not associated with treatment initiation or dose up-titration. Event rates for HF hospitalization and mortality were higher in patients with poor adherence or persistence to GDMTs. CONCLUSIONS: Following a cancer diagnosis, patients with HFrEF were more likely to have reduced use of GDMTs for HF.