Nicotinamide

metabolite

Nicotinamide reflects altered NAD+ metabolism and energetic stress during myocardial ischemia.

Pathway placement

Cascade stepOff-pathway / systemic markers

Confidencemedium

RationaleNAD+ precursor; systemic metabolic marker reflecting ischemic energetic stress but not atherothrombotic mechanism.

Druggability

Not assessed (no mapped human gene target).

Type I vs Type II discrimination

ScoresIndeterminate

R — rupture / Type-I

—

C — confounder / Type-II

A — assay feasibility

E — evidence strength

T1DI (composite)

Specificity differential (R−C)-26.7

Confounder panel (Type-II drivers)

1sepsis / systemic inflammationmag 2

2anemia / acute blood lossn/a

3hypovolemia / dehydrationn/a

4tachyarrhythmiamag 1

5hypoxemia / respiratory failuren/a

6hypertensive emergencymag 0

7high-demand / peri-operative stressmag 2

Coverage: 4/7 confounders with evidence

Tier: deep-scored (abstract-extracted) · 6 supporting references. See the discrimination table for all markers.

Class-level default (no specific cleared assay)— generic method inferred from analyte class; confirm against a specific product insert before use.

Specimen

Serum, plasma or urine

Collection tube

Serum separator (gold/red-top, SST) · Lithium heparin (green-top) · Sterile urine container

Method / principle

LC-MS/MS (targeted metabolomics) or enzymatic colorimetric where available

Reagent / substrate

Stable-isotope-labeled internal standard (MS); or enzyme-coupled Trinder reagent

Platform

LC-MS/MS; some automated chemistry

Turnaround · availability

Send-out / research · Specialized / research