Reports on the burden of heart failure (HF) have largely omitted HF diagnosed in outpatient settings. We quantified annual incidence rates ([IR] per 1,000 person years) of HF identified in ambulatory clinics, emergency departments (EDs), and during hospital stays in a national probability sample of Medicare beneficiaries from 2008 to 2014, by age and race/ethnicity. A 20% random sample of Medicare beneficiaries ages ≥65 years with continuous Medicare Parts A, B, and D coverage was used to estimate annual IRs of HF identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Of the 681,487 beneficiaries with incident HF from 2008 to 2014, 283,451 (41%) presented in ambulatory clinics, 76,919 (11%) in EDs, and 321,117 (47%) in hospitals. Overall, incidence of HF in ambulatory clinics decreased from 2008 (IR 22.2, 95% confidence interval [CI] 22.0, 22.4) to 2014 (IR 15.0, 95% CI 14.8, 15.1). Similarly, incidence of HF-related ED visits without an admission to the hospital decreased somewhat from 2008 (IR 5.5, 95% CI 5.4, 5.6) to 2012 (IR 4.2, 95% CI 4.1, 4.3) and stabilized from 2013 to 2014. Similar to previous reports, HF hospitalizations, both International Classification of Diseases, Ninth Revision, Clinical Modification code 428.x in the primary and any position, decreased over the study period. More than half of all new cases of HF in Medicare beneficiaries presented in an ambulatory clinic or ED. The overall incidence of HF decreased from 2008 to 2014, regardless of health-care setting. In conclusion, consideration of outpatient HF is warranted to better understand the burden of HF and its temporal trends.
