Coronary Artery Disease Scores

ADAPT 2-Hour Accelerated Diagnostic Protocol Calculator – Emergency Chest Pain

Clinical calculation support · Verify results before clinical use

ADAPT clinical assessment

Complete the TIMI variables, ECG assessment, and paired 0- and 2-hour troponin I results.

—TIMI score

1. Immediate safety screen

Do not use an accelerated rule-out pathway when an emergency diagnosis or immediate intervention is suspected.

STEMI / STEMI-equivalent or indication for immediate reperfusion?

Hemodynamic instability, significant heart failure, or ongoing/refractory ischemia?

Another life-threatening diagnosis suspected (e.g., aortic dissection or pulmonary embolism)?

2. TIMI risk score for UA/NSTEMI

One point for each variable present. The original ADAPT low-risk definition requires a TIMI score of exactly 0.

Age ≥65 years

At least 3 CAD risk factors*

Known coronary artery disease (stenosis ≥50%)

≥2 anginal episodes in the preceding 24 hours

Aspirin use in the preceding 7 days

ST-segment deviation ≥0.5 mm on presenting ECG

*CAD risk factors in the original TIMI definition: family history of CAD, hypertension, hypercholesterolemia, diabetes mellitus, or current smoking. The seventh TIMI variable (elevated cardiac biomarkers) is derived below from the initial troponin I result and the entered assay upper reference limit.

3. ECG assessment

The ADAPT protocol requires no new ischemic changes on the initial ECG (changes known to be pre-existing are not considered new).

No new ischemic changesProtocol criterion met

New ischemic changes presentCriterion not met

4. Serial troponin I

Enter values from the same contemporary (non-high-sensitivity) laboratory cTnI assay. Use the assay-specific institutional cutoff used to define an elevated cTnI result (typically aligned with the assay URL under local laboratory policy) and the same units for all values.

Institutional cTnI elevation cutoff / assay URL

Reported unit

Troponin I at 0 hours

Troponin I at 2 hours

Was the second sample collected at the 2-hour protocol time point?

Assay type

The original ADAPT study used contemporary laboratory troponin I and the local institutional elevation cutoff. Enter the cutoff specified by your laboratory; this calculator does not convert or infer assay-specific cutoffs. Do not apply the original ADAPT thresholds to hs-cTnI or cTnT as though they were validated for those assays; use a locally validated, assay-specific hs-cTn pathway instead.

—TIMI score

ADAPT pathway assessment

Complete all required fields

The protocol result will appear when the required clinical and laboratory inputs are entered.

Criteria summaryNo assessment performed.

About the ADAPT protocol

The ADAPT (2-hour accelerated diagnostic protocol) was evaluated in emergency-department patients presenting with chest pain suggestive of acute coronary syndrome. Its original low-risk classification requires all of the following: TIMI risk score of 0, no new ischemic changes on the initial ECG, and cardiac troponin I below the institutional cutoff at both 0 and 2 hours.

TIMI score variables

Variable	Definition	Points
Age	≥65 years	1
CAD risk factors	≥3 risk factors (family history, hypertension, hypercholesterolemia, diabetes, current smoking)	1
Known CAD	Prior coronary stenosis ≥50%	1
Angina	≥2 episodes in preceding 24 hours	1
Aspirin	Use in preceding 7 days	1
ECG	ST-segment deviation ≥0.5 mm	1
Biomarker	Elevated cardiac marker (here: cTnI at 0 h ≥ entered institutional cutoff)	1

Original ADAPT performance

In the prospective ADAPT cohort (n=1,975), 392 patients (20%) were classified as low risk. One of those patients had a 30-day MACE: sensitivity 99.7% (95% CI 98.1–99.9) and negative predictive value 99.7% (95% CI 98.6–100.0). These are study-cohort estimates, not a guarantee of safety or an individualized probability.

Clinical use and limitations

Designed as an adjunct for ED assessment of suspected ACS after immediate emergencies have been addressed.
A TIMI score of 0 alone does not rule out ACS; all ADAPT components must be satisfied.
Use the assay-specific institutional elevation cutoff and correct sampling interval. This tool is intentionally restricted to the original contemporary cTnI approach.
Persistent/recurrent symptoms, dynamic ECG changes, clinical concern, or discordant results require further evaluation regardless of the calculator output.
Low-risk classification is not an automatic discharge order. Disposition requires clinician assessment, follow-up arrangements, and local protocol.

Current guideline context

Contemporary guidance prefers high-sensitivity cardiac troponin and assay-specific accelerated pathways (e.g., validated 0/1-hour or 0/2-hour algorithms). The 2021 AHA/ACC chest pain guideline generally recommends repeat sampling at 1–3 hours for hs-cTn and 3–6 hours for conventional assays. The 2023 ESC ACS guideline recommends validated hs-cTn 0/1-hour or 0/2-hour algorithms. These are not interchangeable with the original ADAPT protocol.

Clinical disclaimer: This calculator supports structured assessment and does not establish or exclude a diagnosis of acute coronary syndrome or myocardial infarction. It must not delay emergency treatment, serial ECGs, additional troponin testing, imaging, or invasive evaluation when clinically indicated. Use local laboratory assay guidance and institutional chest-pain pathways. The original ADAPT evidence should not be extrapolated to different troponin assays, populations, or clinical settings without validation.

References

Than M, Cullen L, Aldous S, et al.2-Hour accelerated diagnostic protocol to assess patients with chest pain symptoms using contemporary troponins as the only biomarker: the ADAPT trial. J Am Coll Cardiol. 2012;59(23):2091–2098. DOI: 10.1016/j.jacc.2012.02.035. PMID: 22578923.

Antman EM, Cohen M, Bernink PJLM, et al.The TIMI risk score for unstable angina/non–ST elevation MI: a method for prognostication and therapeutic decision making. JAMA. 2000;284(7):835–842. DOI: 10.1001/jama.284.7.835. PMID: 10938172.

Than M, Aldous S, Lord SJ, et al.A 2-Hour Diagnostic Protocol for Possible Cardiac Chest Pain in the Emergency Department: A Randomized Clinical Trial. JAMA Intern Med. 2014;174(1):51–58. DOI: 10.1001/jamainternmed.2013.11362. PMID: 24100783.

Gulati M, Levy PD, Mukherjee D, et al.2021 AHA/ACC Guideline for the Evaluation and Diagnosis of Chest Pain. J Am Coll Cardiol. 2021;78(22):e187–e285. DOI: 10.1016/j.jacc.2021.07.053.

Byrne RA, Rossello X, Coughlan JJ, et al.2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J. 2023;44(38):3720–3826. DOI: 10.1093/eurheartj/ehad191.