Persistent mortality and heart failure burden of anterior ST-segment elevation myocardial infarction following primary percutaneous coronary intervention: real-world evidence from the US Medicare Data Set

OBJECTIVES: We sought to compare the temporal trends in the incidence of death and rehospitalisation for congestive heart failure (CHF) following anterior ST-elevation myocardial infarction (STEMI) in a Medicare cohort of beneficiaries treated with primary percutaneous coronary intervention (PCI) in 2005 (n=1479) with those treated in 2016 through quarter (Q) 2 of 2017 (n=22 432). DESIGN: This retrospective analysis examined outcomes using both descriptive and regression analysis to control for differences in patient clinical characteristics over time. PRIMARY OUTCOME MEASURES: The primary outcomes are 1 year and 2 year rates of mortality and re-hospitalisation for CHF. RESULTS: The 1 year mortality rate was numerically higher in the 2016 cohort at 10.3% (95% CI 9.9 to 10.7) versus 8.9% (CI 7.4 to 10.3; p=0.068). The 2 year mortality rate was significantly higher in the 2016 cohort at 14.5% (CI 13.9 to 15.1) versus 11.4% (CI 9.2 to 13.6; p<0.01). The 1 year rehospitalisation for CHF was lower in the 2016 cohort at 10.6% (CI 10.0 to 11.2) versus 16.7% (CI 14.0 to 19.4; p<0.001), but the 2 year rate was not significantly different at 19.3% (CI 17.7 to 20.9) versus 20.7% (CI 16.4 to 24.9; p=0.55). After adjustment for covariates with two models, the 1 year mortality increased by 2.3% (CI 0.8 to 3.7; p<0.01) and 4.1% (CI 2.6 to 5.6; p<0.001) in the 2016 cohort. The 2 year adjusted mortality also increased by 4.2% (CI 2.0 to 6.4; p<0.001) and 6.5% (CI 4.2 to 8.7; p<0.001) in the 2016 cohort. The risk adjusted trends for rehospitalisation for CHF were similar to the unadjusted findings. CONCLUSIONS: Despite prior improvements in STEMI outcomes in the reperfusion era related to the broad adoption of timely PCI, there is a persistent high mortality and CHF burden in Medicare beneficiaries with anterior STEMI. New strategies that address reperfusion injury and enhance myocardial salvage are needed.