HFSA ePoster Library

Introduction: Supersaturated oxygen (SSO2) is an FDA approved adjunctive therapy for delivery to the left anterior descending coronary artery immediately following percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). In prior studies SSO2 was associated with reduction in infarct size, which is a key determinant of heart failure (HF) and mortality. Hypothesis: The burden of re-hospitalization (REHOSP) for HF and mortality remains high following anterior STEMI treated with primary PCI and SSO2 can improve these outcomes.
Methods: The 2005-2008 and 2016-2018 Medicare Data rates of mortality and REHOSP for HF were compared using descriptive and regression analysis to control for differences in clinical characteristics over time. From the 2016-2017 Medicare population a group was identified fulfilling the entrance criteria for the IC-HOT single arm study of SSO2 therapy for anterior STEMI conducted during this same time frame. Each of the 100 IC-HOT participants was matched to a Medicare beneficiary based on propensity score to construct a comparison group with similar characteristics also treated with primary PCI.
Results: The eligible Medicare group for comparison with IC-HOT included 10,634 cases and after matching standardized differences were <20, indicating balance in covariates. The IC-HOT treatment group had reduced mortality compared with the matched Medicare group at 1 year (0 vs 4.6%, p <0.02). REHOSP for HF in IC-HOT was also lower than in the Medicare group at 1 year (1.1 vs 9.2%, p <0.05) despite a significant decrease in the 1-year REHOSP for HF from the early to later Medicare cohort. This occurred with no difference in REHOSP for HF at 2 years between the early and later Medicare cohorts suggesting potential discrepancies impacted by changes in payment policy. The risk-adjusted 1-year and 2-year mortality rates increased from the early to later Medicare cohort with anterior STEMI treated with PCI alone.

Risk-Adjusted Outcomes Between Earlier and Later Medicare Cohorts

Outcome	N	Difference	p-value
1-year mortality	23,911	4.1%	<0.01
1-year HF re-hospitalization	23,911	-4.9%	<0.01
2-year mortality	13,584	6.5%	<0.01
2-year HF re-hospitalization	13,584	0.8%	0.74

Conclusion: Mortality and REHOSP for HF has not improved over the last decade for Medicare patients with anterior STEMI treated with PCI alone. The reduction in infarct size with SSO2 therapy is associated with a decrease in these events and thus has the potential to favorably impact this growing clinical burden in an aging population.