Background: Although guidelines recommend invasive management for non-ST-segment-elevation myocardial infarction (NSTEMI), there is considerable variability in the application of these recommendations across different hospitals, reflecting a lack of standardized clinical pathways and highlighting ongoing uncertainty in real-world practice. We sought to describe site-level variability in the use and timing of invasive angiography for NSTEMI and its association with in-hospital outcomes.
Methods: Using National Cardiovascular Data Registry Chest Pain-MI registry data (2019-2024), the rates and timing of invasive coronary angiography, if any, were characterized among patients with NSTEMI. Hierarchical logistic regression models were created to describe hospital-level variability in management using median odds ratios, adjusted for patient and site characteristics. Inverse probability weighting was used to estimate the association between treatment strategy and in-hospital outcomes.
Results: We included 287 275 patients with type-1 NSTEMI from 541 hospitals (age, 67.6±13.3 years; 36.4% women). Invasive coronary angiography was performed in 87.1%, of whom 56.9% within 24 hours. Among those treated invasively, 66.1% received percutaneous coronary intervention. Older patients with more comorbidities were paradoxically more likely to receive conservative management or delayed intervention (>24 hours). Site-level variability for invasive strategy (versus conservative) was large (median odds ratio, 2.85 (95% CI, 2.64-3.10]), as was early invasive treatment (median odds ratio, 1.67 [95% CI, 1.62-1.74]), particularly on weekends/holidays (median odds ratio, 1.89 [95% CI, 1.81-1.98]). The use of any invasive strategy was associated with lower in-hospital mortality versus conservative management (weighted odds ratio, 0.36 [95% CI, 0.31-0.42]). This finding was consistent across all baseline risk categories (Pinteraction<0.001).
Conclusions: Patients with type-1 NSTEMI and higher-risk clinical profiles were not consistently prioritized to undergo early invasive management with substantial variability across hospitals. Invasive management was associated with lower in-hospital mortality compared with conservative treatment. Future randomized studies in the modern percutaneous coronary intervention era are needed to confirm our findings and identify which patients benefit most and when intervention should occur.
Keywords: acute coronary syndrome; coronary angiography; non-ST elevated myocardial infarction; risk assessment; standard of care.