What does omi refer to in medical terms?

What is OMI in Medical Terms?

OMI has two distinct meanings in medicine: (1) Occlusion Myocardial Infarction in cardiology, and (2) Optical Metabolic Imaging in cancer research.

OMI as Occlusion Myocardial Infarction (Cardiology)

OMI refers to acute myocardial infarction caused by complete coronary artery occlusion, representing a paradigm shift from the traditional STEMI/NSTEMI classification. 1

Definition and Diagnostic Criteria

• OMI is defined as an acute culprit lesion with TIMI 0-2 flow (no flow to partial flow), OR an acute culprit lesion with TIMI 3 flow (normal flow) that was intervened upon with highly elevated troponin (cTnI > 10.0 ng/mL or hs-cTnI > 5000 ng/L) 1
• Alternative definition includes TIMI 0-2 flow or TIMI 3 flow with peak troponin T ≥ 1.0 ng/mL or troponin I ≥ 10.0 ng/mL 2, 3

Critical Clinical Problem

• 40% of patients with acute coronary occlusion (OMI) do not meet STEMI criteria on ECG, leading to dangerous delays in treatment and increased mortality 1, 2
• STEMI criteria have only 41% sensitivity for detecting OMI, while trained interpreters using OMI-specific ECG findings achieve 86% sensitivity 2
• STEMI(-) OMI patients experience median time to catheterization of 437 minutes compared to 41 minutes for STEMI(+) OMI patients (p < 0.001) 3

Clinical Outcomes

• STEMI(-) OMI patients have similar infarct size, mortality, and complication rates as STEMI(+) OMI patients, but suffer from significantly delayed revascularization 1, 2, 3
• Only 11% of STEMI(-) OMI patients received PCI within 12 hours versus 77% of STEMI(+) OMI patients (p < 0.001) 1
• In-hospital mortality for OMI patients was 5.7%, with mechanical complications occurring in approximately 46% of both STEMI(+) and STEMI(-) OMI groups 1

Proposed Paradigm Shift

• The OMI vs. NOMI (Non-Occlusion MI) paradigm focuses on identifying coronary occlusion rather than relying solely on STEMI criteria 2, 3
• This approach aims to ensure all patients with acute coronary occlusion receive emergent reperfusion regardless of whether they meet traditional STEMI criteria 1, 2

OMI as Optical Metabolic Imaging (Cancer Research)

OMI is a label-free imaging technique using multiphoton microscopy to measure cellular metabolism in patient-derived cancer organoids (PDCOs) for drug response assessment. 4

Technical Mechanism

• OMI measures autofluorescence from metabolic coenzymes NAD(P)H (reduced nicotinamide adenine dinucleotide phosphate) and FAD (flavin adenine dinucleotide) 4
• The optical redox ratio (NAD(P)H to FAD fluorescence intensity ratio) provides a label-free measurement of cellular oxidation-reduction state sensitive to malignancy and drug response 4
• The OMI index combines optical redox ratio, mean NAD(P)H lifetime, and mean FAD lifetime, providing superior sensitivity to drug response compared to any single variable 4

Clinical Applications

• OMI enables noninvasive single-cell imaging of functional changes within PDCOs over time, tracking drug resistance evolution and metabolic heterogeneity 4
• The technique has successfully predicted pancreatic cancer patient response to therapy in prospective clinical studies 4
• Wide-field OMI adaptations allow implementation on standard fluorescence microscopes already present in research and clinical labs, improving accessibility 4

Advantages Over Traditional Methods

• OMI fills a critical niche by providing single-cell assessment without sample destruction (unlike genetic sequencing, flow cytometry, or immunohistochemistry) 4
• Single-organoid tracking with OMI provides improved sensitivity compared to pooled well-level assessments 4
• The sensing depth of multiphoton microscopy is sufficient to image through the entire thickness of organoids 4

Context-Specific Usage

In clinical cardiology contexts, OMI refers to occlusion myocardial infarction requiring emergent intervention. 1, 2, 3 In oncology research settings, OMI refers to optical metabolic imaging for drug response testing. 4

Important Caveat

The term "OMI" in outcome measure research stands for "Outcome Measure Instrument," referring to tools used to assess clinical endpoints in trials, which is unrelated to either cardiology or cancer imaging applications 4