Trends in incidence and clinical outcome of non-ST elevation myocardial infarction in patients with amyloidosis in the United States, 2010-2020

Study objective: To assess temporal changes in clinical profile and in-hospital outcome of patients with amyloidosis presenting with non-ST elevation myocardial infarction, NSTEMI.Design/setting: We conducted a retrospective observational study using the National Inpatient Sample (NIS) database from January 1, 2010, to December 31, 2020.Main outcomes: Primary outcome of interest was trend in adjusted in-hospital mortality in patients with amyloidosis presenting with NSTEMI from 2010 to 2020. Our secondary outcomes were trend in rate of coronary revascularization, and trend in duration of hospitalization.Results: We identified 272,896 hospitalizations for amyloidosis. There was a temporal increase in incidence of NSTEMI among patients aged 18-44 years from 15.5 % to 28.0 %, a reverse trend was observed in 45-64 years: 22.1 % to 17.7 %, p = 0.043. There was no statistically significant difference in rate of coronary revascularization from 2010 to 2020; 16.3 % to 14.2 %, p = 0.86. We observed an increased odds of all-cause in-hospital mortality in patients with NSTEMI compared to those without NSTEMI (aOR = 2.2, 95 % CI: 1.9-2.6, p < 0.001) but there was a decrease trend in mortality from 21.5 % to 11.3 %, p = 0.013 for trend. Hospitalization duration was also observed to decreased from 14.1 days to 10.9 days during the study period (p = 0.055 for trend).Conclusion: In patients with amyloidosis presenting with NSTEMI, there was increased incidence of NSTEMI among young adults, a steady trend in coronary revascularization, and a decreasing trend of adjusted all-cause in-hospital mortality and length of hospitalization from 2010 to 2020 in the United States.