Impact of medication nonadherence on hospitalizations and mortality in heart failure.

BACKGROUND

Limited literature exists on the association between medication adherence and outcomes among patients with heart failure.

METHODS AND RESULTS

We conducted a retrospective longitudinal cohort study of 557 patients with heart failure with reduced ejection fraction (HFrEF) (defined by EF <50%) in a large health maintenance organization. We used multivariable Cox proportional hazards models to assess the relationship between adherence (with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, β-blockers, and aldosterone antagonists) and the primary outcome of all-cause mortality plus cardiovascular hospitalizations. Mean follow-up time was 1.1 years. Nonadherence (defined as <80% adherence) was associated with a statistically significant increase in the primary outcome in the cohort overall (hazard ratio 2.07, 95% confidence interval 1.62-2.64; P < .0001). This association remained significant when all 3 classes of heart failure medications and the components of the composite end point were considered separately and when the adherence threshold was varied to 70% or 90%.

CONCLUSIONS

Medication nonadherence was associated with an increased risk of all-cause mortality and cardiovascular hospitalizations in a community heart failure population. Further research is needed to define systems of care that optimize adherence among patients with heart failure.