Characteristics and outcomes in acute myocardial infarction hospitalizations among the older population (age ≥80 years) in the United States, 2004-2018

Importance: Acute myocardial infarction (AMI) is a major health concern among older adults (≥80 years). We analyzed a US national database to evaluate the clinical outcomes, resource utilization, and economic burden of AMI hospitalizations in older patients.

Methods and results: We analyzed the National Inpatient Sample data between January 2004 and December 2018. We examined the trends of clinical characteristics, inpatient mortality, and healthcare cost utilization in older US adults for AMI hospitalizations. We identified 2,174,587 weighted AMI hospitalizations. There was a decrease in AMI hospitalizations per 100,000 older US adults from 1,679 in 2004 to 1036 in 2018, with a more profound decrease in ST-elevation myocardial infarction (STEMI). We noted an overall increase in comorbidities (hypertension, heart failure, dyslipidemia, atrial fibrillation, diabetes, peripheral vascular disease). Overall, inpatient mortality was 10.6%; adjusted inpatient mortality decreased from 14% in 2004 to 8% in 2018 (p trend <0.001)- consistent across sexes and races. There was increased percutaneous intervention (PCI) utilization [19.3% (2004-2008) to 24.0% (2014-2018)] with a concomitant increase in bleeding and acute kidney injury (AKI). Black adults and women underwent revascularization less frequently than White adults and men. White patients had higher inpatient mortality compared to black patients. There was a decrease in adjusted mean length of stay (LOS) from 6.2 days in 2004 to 3.9 days in 2018 (p trend <0.001). There was an increase in discharge disposition to home with a concomitant decrease in utilization of rehabilitation facilities at discharge.

Conclusion: Our study showed that the inpatient mortality and LOS has decreased for AMI hospitalizations in the older patient population in the US. While utilization of revascularization strategies has increased, sex and racial disparities exist in the utilization of PCI.