Background: Major bleeding requiring transfusion after percutaneous coronary intervention (PCI) for myocardial infarction (MI) is associated with high mortality and morbidity. Limited data is available about the differences in the incidence of major bleeding between ST-segment-elevation myocardial infarction (STEMI) and non-ST-segment-elevation myocardial infarction (NSTEMI).
Methods: This is a retrospective cohort study using the 2014 Nationwide Inpatient Sample (NIS) of adult patients hospitalized with STEMI and NSTEMI as the admitting diagnosis who underwent PCI. We aim to determine if the type of MI affects the risk of major bleeding and in-hospital mortality. We adjusted our results for potential confounders including age, gender, race, elective admission, hospital location, hospital teaching status and the Charlson Comorbidity Index.
Results: We identified 53,894 patients (weighted n=269470) admitted for MI who underwent PCI during 2014. We divided them into two groups (STEMI and NSTEMI). The STEMI patients were younger, had higher household incomes, and were more likely to be uninsured. In the STEMI group, 27.9% were female and in the NSTEMI group 33.9% were female (Table 1). More bare metal stents were used in the STEMI group (21.9% vs 15.3%; p<0.01). The overall incidence of major bleeding was 2.16% (95% confidence interval (CI), 2.02-2.30%). There was a 46% greater chance of major bleeding after PCI in the STEMI group (Adjusted OR 1.46, p<0.01). The overall in-hospital mortality was 2.66% (95% CI, 2.52%-2.80%). Our analysis showed the chance of in-hospital mortality in the STEMI group was almost 5 times higher than the NSTEMI group (adjusted odds ratio (OR) 4.94, p<0.01).
Conclusion: PCI in the STEMI patients is associated with a higher risk of major bleeding and a higher probability of in-hospital deaths compared to the NSTEMI group.