TIMI Score Calculator for UA/NSTEMI – Cardiac Risk Assessment
The TIMI Score Calculator for UA/NSTEMI calculates the TIMI risk score for patients presenting with unstable angina or non-ST-elevation myocardial infarction. Enter age, number of CAD risk factors, prior coronary stenosis, ST deviation on ECG, number of anginal events in the past 24 hours, prior aspirin use, and elevated cardiac markers. Get the TIMI score, risk category, estimated 14-day event rate, and management recommendation. For use by qualified healthcare professionals only. Always interpret in full clinical context. Consult a cardiologist for patient management decisions.
Formula
This calculator transforms the provided inputs into the requested outputs using standard domain equations.
Quick Tip
Use this output as guidance and confirm clinical decisions with a qualified professional.
Assessing a UA/NSTEMI patient and need a quick TIMI risk stratification? Enter the seven components. Get the score, risk category, and estimated event rate — instantly at the bedside.
Featured Answer
Q: How do I calculate the TIMI score for UA/NSTEMI?
A: The TIMI score for UA/NSTEMI adds one point for each of seven criteria: age ≥ 65, three or more CAD risk factors, prior coronary stenosis ≥ 50%, ST deviation on admission ECG, two or more anginal events in 24 hours, prior aspirin use in the past 7 days, and elevated serum cardiac markers. Scores range 0–7. Score 0–2 is low risk (5% event rate), 3–4 intermediate (13%), 5–7 high risk (26–41%). Use this calculator for instant bedside stratification.
How to Use TIMI Score Calculator for UA/NSTEMI
- Enter age — score 1 point if age is 65 or older.
- Enter CAD risk factors — score 1 point for three or more risk factors (hypertension, hyperlipidaemia, diabetes, family history, smoking).
- Enter prior stenosis — score 1 point if known prior coronary stenosis of 50% or more.
- Enter ST deviation — score 1 point for ST segment deviation on the admission ECG.
- Enter anginal events — score 1 point for two or more anginal events in the past 24 hours.
- Enter aspirin use — score 1 point for aspirin use within the prior 7 days.
- Enter cardiac markers — score 1 point for elevated serum cardiac markers (troponin or CK-MB).
What is the TIMI Risk Score for UA/NSTEMI?
The TIMI risk score for Unstable Angina and Non-ST-Elevation MI (UA/NSTEMI) is a validated clinical tool for stratifying short-term ischaemic risk.
It was developed from the TIMI 11B and ESSENCE trials. It assigns one point for each of seven readily available clinical and ECG features.
Scores range from 0 to 7. Higher scores indicate higher risk of death, MI, or need for urgent revascularisation within 14 days.
The score guides both urgency of intervention and treatment intensity. High-risk patients typically benefit from early invasive strategy. Low-risk patients may be managed conservatively.
Example: Age 72, 3 CAD risk factors, prior 60% stenosis known, ST depression on ECG, 3 anginal events in 24 hours, aspirin taken yesterday, troponin elevated.
| TIMI Component | Points |
|---|---|
| Age ≥ 65 | 1 |
| ≥ 3 CAD risk factors | 1 |
| Prior stenosis ≥ 50% | 1 |
| ST deviation | 1 |
| ≥ 2 anginal events | 1 |
| Aspirin use in 7 days | 1 |
| Elevated markers | 1 |
| TIMI Score | 7 — High Risk |
TIMI Score for UA/NSTEMI: Risk Stratification at the Bedside
Why TIMI Score Calculator Matters
Not all chest pain presentations carry the same risk. A 68-year-old with three CAD risk factors, ST depression, and elevated troponin is very different from a 40-year-old with atypical chest pain and no risk factors.
The TIMI score gives a structured, validated framework for that stratification. It takes seven clinical data points and converts them into an actionable risk category. The score is calculated in under two minutes at the bedside.
High-risk patients are directed toward early angiography. Low-risk patients can be managed conservatively without unnecessary cath lab activation.
How the TIMI Score Is Calculated — Step by Step
- Age ≥ 65 years: +1
- Three or more CAD risk factors: +1 (hypertension, hyperlipidaemia, diabetes, family history, current smoking)
- Known coronary artery stenosis ≥ 50%: +1
- ST-segment deviation on admission ECG: +1
- Two or more anginal events in the prior 24 hours: +1
- Use of aspirin in the prior 7 days: +1
- Elevated serum cardiac markers (troponin or CK-MB): +1
- Sum all points: minimum 0, maximum 7.
TIMI Score Risk Categories and Event Rates
| TIMI Score | Risk Category | 14-Day Event Rate |
|---|---|---|
| 0–1 | Low | ~5% |
| 2 | Low-Intermediate | ~8% |
| 3–4 | Intermediate | ~13–20% |
| 5–7 | High | ~26–41% |
Event rate = composite of death, new or recurrent MI, or need for urgent revascularisation at 14 days.
Common Mistakes to Avoid
- Confusing TIMI UA/NSTEMI with TIMI STEMI. These are different scores for different presentations. Never apply the STEMI score to a UA/NSTEMI patient.
- Scoring aspirin incorrectly. Prior aspirin use within 7 days scores positively — it suggests aspirin-refractory ischaemia, which increases risk.
- Missing the 24-hour anginal event window. The criterion is two or more events in the prior 24 hours specifically — not a lifetime history.
- Over-relying on score alone. Clinical gestalt, haemodynamic status, and comorbidities influence management equally. The score is an aid, not a replacement for clinical judgement.
- Not considering local guideline adaptation. Some centres use modified thresholds or combine TIMI with other scores like GRACE or HEART.
When to Use This Calculator
Use this tool in the emergency department or CCU when evaluating a patient presenting with chest pain consistent with UA/NSTEMI.
Apply after initial assessment, ECG review, and first troponin result is available. The score guides the urgency and intensity of further management.
For overall cardiac risk outside the acute setting, a general cardiovascular risk score calculator is more appropriate. For neonatal risk stratification, the Newborn Hyperbilirubinemia Calculator handles that clinical context.
Pro Tips
TIMI score — the raw number drives the clinical action. Score ≥ 5 typically warrants consideration of early invasive strategy within 24 hours.
Risk category — use the category label in documentation. Low, intermediate, and high risk are recognised across clinical teams and support standardised handover.
Event rate percent — share this figure with the patient and family when discussing urgency. Concrete numbers support informed decision-making.
Management recommendation — cross-reference with your local ACS protocol. The TIMI score aligns with ACC/AHA NSTEMI guidelines but local pathways may vary.
Important Assumptions and Limitations
The TIMI score was derived from the TIMI 11B and ESSENCE trial populations. It performs best in patients with a clear ACS presentation. It may underperform in certain subgroups such as elderly patients with atypical presentations or those with non-cardiac chest pain. This tool is for clinical reference only. All patient management decisions must be made by a qualified clinician. Calculation reviewed against original TIMI UA/NSTEMI score publication references.
For patient management decisions, consult a qualified cardiologist.
Frequently Asked Questions
Find answers to common questions about TIMI Score Calculator for UA/NSTEMI
The TIMI risk score for Unstable Angina and NSTEMI is a validated seven-point scoring system for short-term ischaemic risk stratification. It was derived from the TIMI 11B and ESSENCE trials. Scores range from 0 to 7. Higher scores indicate higher risk of death, myocardial infarction, or need for urgent revascularisation within 14 days of presentation.
Add one point for each positive criterion: age ≥ 65, three or more CAD risk factors, prior coronary stenosis ≥ 50%, ST deviation on ECG, two or more anginal events in 24 hours, aspirin use in the prior 7 days, and elevated cardiac markers. Sum the points. Score 0–2 is low risk, 3–4 intermediate, 5–7 high risk with event rates of 5–41%.
The TIMI score is a validated clinical tool with documented discriminatory ability in the original trial populations. Accuracy depends on correct input of all seven criteria. The score performs best in patients with clear ACS features. It may be less discriminating in atypical presentations, elderly patients, and those with non-cardiac diagnoses. Always apply in full clinical context.
Risk category classifies the TIMI score into low (0–2), intermediate (3–4), or high (5–7) risk groups. Each category corresponds to a published 14-day event rate. Low risk has approximately 5% event probability. High risk has 26–41% event probability. The category guides urgency of intervention — high-risk patients typically benefit from early invasive strategy within 24 hours.
Calculate the TIMI score after initial evaluation of a chest pain patient — once the ECG is reviewed and at least one troponin result is available. It should be applied to patients with suspected UA/NSTEMI, not STEMI presentations (which have their own separate TIMI score). The score is most useful as a bedside decision support tool during early triage and risk stratification.
A TIMI score of 5 is in the high-risk category. The corresponding 14-day event rate is approximately 26%. This means roughly 1 in 4 patients with a TIMI score of 5 will experience death, non-fatal MI, or require urgent revascularisation within 14 days. Scores of 6–7 carry even higher rates of 40–41%. These patients warrant prompt cardiological review.
Prior aspirin use within 7 days is a positive risk criterion because it suggests aspirin-refractory ischaemia. A patient who has been on aspirin and still develops an acute coronary syndrome may have more severe or widespread coronary disease. This is paradoxically a higher-risk feature. The criterion reflects clinical reality — not a suggestion that aspirin is harmful.
Both scores stratify ACS risk but use different variables. TIMI UA/NSTEMI uses seven binary criteria and is simpler to calculate at the bedside. GRACE uses continuous variables including heart rate, blood pressure, creatinine, and Killip class — it provides more granular risk discrimination. ACC/AHA guidelines favour GRACE for in-hospital mortality prediction and TIMI for early risk stratification guidance.