hs-cTnI ACS Calculator

CSR-ED Decision Thresholds — Abbott Alinity hs-cTnI (ng/L)

Decision Point	Male	Female	Action
99th Percentile URL	> 35 ng/L	> 14 ng/L	Above = detectable elevation
Immediate Rule-In	> 64 ng/L	> 64 ng/L	RULE IN — no serial troponin needed
Rapid Rule-Out (0h)	< 3 ng/L	< 3 ng/L	If HEART 0–3 AND symptoms > 3h

1-Hour Delta (Δ)	Interpretation	Pathway
Δ ≥ 5	+ any hs-cTnI > 99th% → Acute MI	RULE IN: High Risk
Δ ≥ 5	No value > 99th%	Intermediate Risk (Observe)
Δ 3–4	Indeterminate	Intermediate Risk (Observe)
Δ ≤ 2	+ HEART 0–3 AND symptoms > 3h	RULE OUT ACS
Δ ≤ 2	Does NOT meet rule-out criteria	Intermediate Risk (Observe)

**Definition of Acute MI: At least one hs-cTnI > 99th percentile AND delta > 5 ng/L

HEART Score — Troponin (T) Component by Sex

Points	Male	Female
0 points	< 35 ng/L	< 14 ng/L
1 point	36–104 ng/L	15–41 ng/L
2 points	≥ 105 ng/L	≥ 42 ng/L

T component auto-calculated from sex and 0-hour hs-cTnI value below.

Patient Input

Sex

Male Female

Time from symptom onset

< 3 hours ≥ 3 hours

*If time of onset is unclear, time of presentation = time of onset

Step 1: Draw 0-hour troponin

0-hour hs-cTnI (ng/L) required

Step 2: Repeat at 1 hour (if indicated)

1-hour hs-cTnI (ng/L) optional — enter when drawn

Step 3: Repeat at 3 hours (intermediate pathway only)

3-hour hs-cTnI (ng/L) optional — for intermediate pathway

HEART Score

H — History

E — ECG

A — Age

R — Risk Factors

T — Initial Troponin (auto-calculated from sex + 0h hs-cTnI)

Enter 0-hour hs-cTnI above to auto-calculate

CSR-ED ACS Pathway Result

Reference

CSR-ED ACS Flowchart — High Sensitivity Troponin with Abbott Alinity 0/1/3-hour. CHRISTUS Spohn Health System, August 2025.
Acute MI Definition: At least one hs-cTnI > 99th percentile AND delta > 5 ng/L. 99th% URL: Male > 35 ng/L; Female > 14 ng/L.
HEART Score: Backus BE, et al. A prospective validation of the HEART score. Neth Heart J 2010. PMID 20386704.
HEART Score T component uses sex-specific thresholds per CSR-ED protocol (Women: ≥42=2, 15-41=1, <14=0; Men: ≥105=2, 36-104=1, <35=0).

YBEMUS · Guy Youngblood, MD, FACEP, FAAEM
CCEMRP · BCM/CHRISTUS Children's PEM Fellowship
For educational use. Always apply clinical judgment. This tool does not replace physician assessment.

🫀 Abbott Alinity hs-cTnI ACS Calculator