Abstract Body (Do not enter title and authors here): Background: Non-ST elevation acute coronary syndrome (NSTE-ACS) is a leading cause of cardiovascular morbidity, with variable mortality across age groups. Older patients exhibit higher in-hospital mortality and often experience delayed percutaneous coronary intervention (PCI) owing to comorbidities. Large-scale data on PCI and inpatient mortality trends are limited.
Aim: To evaluate inpatient mortality rates of NSTE-ACS treated with PCI over a 15-year period, comparing trends based on age groups.
Methods: We used the National Inpatient Sample from 2005 to 2019 to identify the study population using the International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification. The primary outcome was the PCI trend of NSTE-ACS among age groups. The secondary outcome was in-hospital mortality. Multivariate logistic regression and adjustment for sex, race, and Charlson comorbidity index score were used.
Results: We evaluated 6,645,610 patients hospitalized in the United States for NSTE-ACS. Of these, 2,291,282 (34.4%) underwent PCI; mean age was 64.8 years, and 34.3% were female. PCI rates increased in all age groups during the study period; however, they remained significantly lower in patients above 80 years of age. The rate of PCI increased from 38% to 44.7% in the 18-64 years age group, from 29.1% to 43.1% in the 65-79 years age group, and from 15.6% to 31.7% in those 80 years and older during the study period (P<.001) (Figure 1). Furthermore, inpatient mortality rates decreased significantly across all age groups. From 2005-2007 to 2017-2019, mortality rates declined from 1.1% to 0.8% in the 18-64 years age group (P<.001), from 2.5% to 1.6% in the 65-79 years age group (P<.001), and from 4.8% to 2.9% in those aged 80 years and older (P<.001).
Conclusion: From 2005 to 2019 (15 years), an increasing number of patients with NSTE-ACS underwent invasive treatment with PCI each year, most notably in those aged 80 years and older. This was associated with a decline in inpatient mortality across all age groups, greatest in those 80 years of age and older. These results are reassuring as people are living longer and NSTE-ACS is increasingly identified in an older population group.