The influence of heart failure on clinical and economic outcomes among older adults ≥75 years of age with acute myocardial infarction

Background: We aimed to evaluate the influence of heart failure (HF) on clinical and economic outcomes among older adults ≥75 years of age during their acute myocardial infarction (AMI) admission in large population-based study from the United States. We also evaluated the clinical characteristics associated with the presence of HF and the predictors of mortality, healthcare utilization, and cost among older adults with AMI.

Methods: From January 1, 2000, to December 31, 2016, AMI admission was identified using the primary diagnosis and concomitant HF was identified using any non-primary diagnoses in the Premier Healthcare Database.

Results: Of the 468,654 patients examined, 42,946 (9%) had concomitant HF during their AMI admission. These patients were older, more often female, and were more likely to be White. Patients with concomitant HF were more likely to be frail than non-HF patients (59% vs 15%, P < .001). The mean (SD) Elixhauser comorbidity index was 2.6 (2.5) vs 0.4 (1.1), P < .001 in the AMI with HF vs AMI only group. The use of percutaneous coronary intervention in those with AMI and HF was lower than those with AMI only (15% vs 31%, P < .001). The overall mortality rate for those with HF was 12%, the median [IQR] hospital length of stay was 5 [3,9] days, and only 25% of patients were discharged home. A higher proportion of patients were discharged to rehabilitation or hospice if they had AMI and HF (Rehabilitation: 33% vs 20%, P < .001; Hospice: 5% vs 3%, P < .001). The mean unadjusted cost of an AMI hospitalization in patients with concomitant HF was lower ($12,411 ± $14,860) than in those without HF ($15,828 ± $19,330). After adjusting for age, gender, race, hypertension, frailty, revascularization strategy, and death, the average cost of hospitalization attributed to concomitant HF was +$1,075 (95% CI +876 to $1,274) when compared to AMI patients without HF.

Conclusion: In patients ≥75 years of age, AMI with concomitant HF carries higher risk of death, but at ages ≥85 years, the risk difference diminishes due to other competing risks. HF was also associated with longer hospital length of stay and higher likelihood of referral to hospice and rehabilitation facilities when compared to older patients without HF. Care for these older adults is associated with increased hospitalization costs. Measures to identify HF in older adults during their AMI admission are necessary to optimize health outcomes, care delivery, and costs.