Outcomes in non-ST-segment elevation myocardial infarction complicated by in-hospital cardiac arrest based on management strategy.

Background: There are limited data on in-hospital cardiac arrest (IHCA) complicating non-ST-segment-elevation myocardial infarction (NSTEMI) based on management strategy.

Methods: We used National Inpatient Sample (2000-2017) to identify adults with NSTEMI (not undergoing coronary artery bypass grafting) and concomitant IHCA. The cohort was stratified based on use of early (hospital day 0) or delayed (≥hospital day 1) coronary angiography (CAG), percutaneous coronary intervention (PCI), and medical management. Outcomes included incidence of IHCA, in-hospital mortality, adverse events, length of stay, and hospitalization costs.

Results: Of 6,583,662 NSTEMI admissions, 375,873 (5.7 %) underwent early CAG, 1,133,143 (17.2 %) received delayed CAG, 2,326,391 (35.3 %) underwent PCI, and 2,748,255 (41.7 %) admissions were managed medically. The medical management cohort was older, predominantly female, and with higher comorbidities. Overall, 63,085 (1.0 %) admissions had IHCA, and incidence of IHCA was highest in the medical management group (1.4 % vs 1.1 % vs 0.7 % vs 0.6 %, p < 0.001) compared to early CAG, delayed CAG and PCI groups, respectively. In adjusted analysis, early CAG (adjusted OR [aOR] 0.67 [95 % confidence interval {CI} 0.65-0.69]; p < 0.001), delayed CAG (aOR 0.49 [95 % CI 0.48-0.50]; p < 0.001), and PCI (aOR 0.42 [95 % CI 0.41-0.43]; p < 0.001) were associated with lower incidence of IHCA compared to medical management. Compared to medical management, early CAG (adjusted OR 0.53, CI: 0.49-0.58), delayed CAG (adjusted OR 0.34, CI: 0.32-0.36) and PCI (adjusted OR 0.19, CI: 0.18-0.20) were associated with lower in-hospital mortality (all p < 0.001).

Conclusion: Early CAG and PCI in NSTEMI was associated with lower incidence of IHCA and lower mortality among NSTEMI-IHCA admissions.