Occlusion-Focused Triage vs Very-High-Risk NSTEMI Criteria: A DIFOCCULT-3 Substudy

The current ST-segment elevation myocardial infarction (STEMI)/NSTEMI framework may not fully identify patients with ACO who present without diagnostic STE. Although immediate invasive management is recommended for patients with very-high-risk NSTEMI features, these criteria are inconsistently applied in clinical practice. The OMI/NOMI framework has been proposed as an alternative strategy.

This study sought to compare the occlusive and nonocclusive myocardial infarction (OMI/NOMI) classification with guideline-defined very-high-risk non-ST-segment elevation myocardial infarction (NSTEMI) criteria for the identification of acute coronary occlusion (ACO) in patients without diagnostic STE.

This was a substudy of the multicenter, cluster-randomized DIFOCCULT-3 (Time for a Diagnostic Paradigm Shift From ST-Elevation/Non-ST-Elevation to Occlusion/Non-Occlusion Myocardial Infarction-3) trial. Consecutive adult patients without diagnostic STE on the admission electrocardiogram were included and managed according to either the conventional STEMI/NSTEMI or the OMI/NOMI approach. Very-high-risk NSTEMI was defined according to current guidelines. Outcomes included immediate invasive management (within 2 hours) and adjudicated ACO.

Among 4,398 patients, very-high-risk NSTEMI criteria identified a small proportion of patients and were inconsistently translated into early intervention. The OMI/NOMI approach selected more patients for early invasive management compared with the STEMI/NSTEMI framework (45.4% vs 13.6%; P < 0.001). Adjudicated ACO was identified within 2 hours more frequently under the OMI/NOMI approach (35.1% vs 16.7%; P < 0.001), without reduction in angiographic yield.

An occlusion-focused diagnostic approach was associated with substantially higher rates of immediate invasive management and earlier identification of patients with adjudicated ACO.