OBJECTIVES: Sacubitril/valsartan, an angiotensin receptor/neprilysin inhibitor (ARNi), is one of the newest drug classes with efficacy in improving heart failure (HF) outcomes. We aimed to determine the longitudinal adherence patterns of ARNi among Medicare beneficiaries with HF and to identify factors associated with ARNi adherence.

METHODS: In a 15% sample of 2015-2018 Medicare beneficiaries, we identified HF patients who initiated ARNi and were followed up for 1 year. We calculated the proportion of days covered (PDC) of ARNi for each patient every 30 days over the first year following ANRi initiation. A group-based trajectory model (GBTM) was applied to identify patient groups with similar adherence patterns during the follow-up year. We constructed to identify factors associated with the adherence trajectories membership.

RESULTS: Among 9475 eligible beneficiaries (mean ± sd age 77±7 years, 34% female), we identified 5 distinct ARNi adherence trajectories: 1) immediate discontinuers, who discontinued treatment within the first 3 months (12%), 2) early discontinuers, who discontinued treatment in months 4 to 7 (10%), 3) late discontinuers, who discontinued treatment in months 7 to 10 (12%), 4) intermittent adherents, whose adherence fallen early and then showed an increasing trend (12%), and 5) consistently adherents, who continued treatment throughout the 12 months (54%). Living in a socioeconomically disadvantaged area, i.e., county with a top 20% area deprivation index, (adjusted odds ratio [aOR], 1.12 [95% CI, 1.00-1.25]) and Black race (1.43, [95% CI, 1.24-1.64]) were associated with a higher likelihood of being an ARNi non-consistently adherent. Receiving prescriptions from a cardiologist (0.65, [95% CI, 0.58-0.78]) was associated with a lower likelihood of not consistently adherent to ARNi.

CONCLUSIONS: Only half of ARNi users were consistently adherent to the drug in the first year of their initiation. Significant racial and socioeconomic disparities in ARNi adherence were identified.