OBJECTIVES: There is limited information on care for the oldest of our elderly despite the availability of efficacious cardiovascular treatments and population-level outcome improvements. We examined age-related treatment use and survival among persons aged 65+ who were hospitalized with a new acute myocardial infarction (AMI).

METHODS: Using within-country comparisons and US Medicare and Norwegian national data (2009-2015), we examined treatments and survival among those aged 66+ years (allowing for a one-year look-back period). We examined use of evidence-based treatments (e.g., statins, beta-blockers, and bypass surgery) and all-cause mortality at 30-days, and at 365-days. The regression models allowed for age splines and adjusted for comorbidities (Charlson score). In sensitivity analyses, we examined models altering the functional form.

RESULTS: There were 128,393 US subjects (20% random sample) and 39,566 Norwegian subjects who had a new AMI. Mortality at 30-days was 4.9% in the US and 2.6% in Norway among those aged 66 years. Evidence-based treatment use and survival after an initial AMI was lower among older versus younger US subjects. There were additional age-related reductions in medication use and survival at 80 years, compared with younger subjects (e.g., 1.2 percentage point [pp] change in 365-day mortality; 95%CI:1.1-1.3). There were similar patterns in Norway, but larger changes after age 80 years (e.g., 2.0; 95%CI:1.8-2.2 v. 1.2pp mortality change). Adjustment for evidence-based treatments mitigated the increased mortality in the 80+ group within each country (e.g., 0.50pp; 95%CI:0.33-0.67 in Norway and 0.47pp; 95%CI:0.37-0.57 in the US).

CONCLUSIONS: The older elderly are less likely receive evidence-based care after a new AMI and more likely to die within 30- or 365-days compared with the younger elderly in both the US and Norway. The reductions were consistent across all evidence-based treatments and coincided with increases in mortality, suggesting potential undertreatment of the elderly.