TIMI Score Calculator for UA/NSTEMI
Calculate 14-day risk of death, MI, or urgent revascularization in unstable angina and non-ST elevation myocardial infarction patients.
Select Yes or No for each of the seven TIMI risk factors, then click Calculate to see the score, estimated event rate, and risk category.
TIMI Score Calculator for UA/NSTEMI
Calculate 14-day risk of death, MI, or urgent revascularization in unstable angina and non-ST elevation myocardial infarction patients.
About the TIMI Score for UA/NSTEMI
The TIMI (Thrombolysis in Myocardial Infarction) Risk Score for Unstable Angina and Non-ST Elevation Myocardial Infarction is a validated clinical decision tool that predicts the 14-day risk of three major adverse cardiac outcomes: death, new or recurrent myocardial infarction, or urgent coronary revascularization. Developed by Antman and colleagues from the TIMI 11B and ESSENCE trial data, the score was published in 2000 and has since become one of the most widely used risk stratification instruments in the emergency department and coronary care unit.
The score consists of seven binary (yes or no) risk factors, each contributing one point. The factors capture patient demographics, clinical history, and acute presentation features: age 65 or older; the presence of three or more traditional cardiovascular risk factors (diabetes, hypertension, hypercholesterolemia, active smoking, or family history of coronary artery disease); known coronary artery disease with prior stenosis of 50% or greater; ST-segment deviation of at least 0.5 millimeters on the presenting electrocardiogram; two or more anginal events within the preceding 24 hours; aspirin use within the prior seven days; and elevated serum cardiac markers such as troponin or CK-MB. The total score therefore ranges from 0 to 7.
Risk stratification based on the TIMI score correlates closely with 14-day event rates observed in the original trials. A score of 0–1 carries a low event rate of approximately 4.7%. A score of 2 corresponds to roughly 8.3%; score 3, about 13.2%; score 4, about 19.9%; score 5, about 26.2%; and scores of 6 or 7, roughly 40.9%. These gradients help clinicians match treatment intensity to individual patient risk, informing decisions about early invasive strategy, antiplatelet therapy, anticoagulation, and disposition.
The aspirin factor deserves special explanation. Aspirin use in the 7 days preceding the event is a surrogate marker for pre-existing, symptomatic coronary artery disease rather than a protective factor. Patients already on aspirin for cardiovascular indications have a higher baseline risk because they have known or suspected CAD requiring antiplatelet therapy. This counter-intuitive element is one of the most commonly misunderstood aspects of the TIMI scoring system.
The TIMI score has been externally validated in numerous prospective studies across diverse patient populations and healthcare settings. Its simplicity makes it practical at the bedside with no laboratory waiting time beyond standard ACS workup. However, it was designed to complement, not replace, clinical judgment. Other validated tools such as the GRACE and HEART scores may provide additional prognostic granularity in specific settings. The TIMI score should always be interpreted in the context of the full clinical picture, including comorbidities, contraindications to therapy, and patient preferences. This calculator is for educational and decision-support purposes only and is not a substitute for professional medical evaluation.
TIMI UA/NSTEMI score examples
These examples illustrate how different combinations of risk factors translate into TIMI scores and estimated event rates.
| Risk Factors Present | TIMI Score | 14-Day Event Rate |
|---|---|---|
| No risk factors — young patient, no significant cardiac history, normal ECG and biomarkers | Score 0–1 | ~4.7% — Low risk; conservative management with medical therapy often appropriate. |
| Age ≥65, known CAD stenosis ≥50%, ST changes on ECG (3 factors) | Score 3 | ~13.2% — Moderate risk; early cardiology consultation and consideration of invasive evaluation. |
| Age ≥65, known CAD, aspirin use, severe angina, elevated troponin, ST depression (6 factors) | Score 6 | ~40.9% — Very high risk; immediate invasive evaluation and intensive medical therapy warranted. |
| All seven TIMI risk factors present | Score 7 | ~40.9% — Maximum risk; urgent catheterization and aggressive antiplatelet/anticoagulation therapy. |
How to use the TIMI UA/NSTEMI calculator
- Review the patient's age, medical history, current medications (especially aspirin), and the presenting ECG and cardiac biomarker results.
- Select Yes or No for each of the seven TIMI risk factors. All seven must be answered; unknown or borderline findings should default to No.
- Click Calculate TIMI Score to compute the total score (0–7) and the corresponding 14-day adverse event rate.
- Review the risk category (Low through Very High) and use it to guide decisions about treatment intensity, invasive evaluation, and disposition.
- Click Reset to clear all entries for a new patient, or click one of the Load Example buttons to explore common clinical scenarios.
TIMI UA/NSTEMI calculator FAQ
What does the TIMI score for UA/NSTEMI predict?
The TIMI score predicts the 14-day probability of three major adverse cardiac events: death, new or recurrent myocardial infarction, or urgent coronary revascularization. It was derived from patients enrolled in the TIMI 11B and ESSENCE trials and has been validated across multiple ACS populations.
Why does aspirin use count as a positive (risk-increasing) factor?
Aspirin use in the prior 7 days is included as a surrogate marker for pre-existing symptomatic coronary artery disease. Patients already taking aspirin for cardiovascular indications have a higher baseline risk. It is counter-intuitive but reflects a higher-risk population rather than treatment failure per se.
What cardiac markers qualify as 'elevated'?
Any troponin I, troponin T, or CK-MB value above the laboratory's upper reference limit (URL) qualifies. With high-sensitivity troponin assays now in widespread use, even minor elevations above the 99th percentile URL should be counted. The original TIMI studies predated high-sensitivity assays, so apply clinical judgment for borderline values.
How should the TIMI score guide clinical management?
Scores of 0–2 generally support conservative management with medical therapy. Scores of 3–4 often warrant early cardiology consultation and consideration of coronary angiography. Scores of 5–7 typically favor an early invasive strategy within 24–48 hours or more urgently. Always integrate the score with other clinical factors and institutional protocols.
How does the TIMI score compare to the GRACE and HEART scores?
All three are validated ACS risk tools but differ in design. The GRACE score includes more continuous variables and better predicts in-hospital and 6-month mortality. The HEART score was designed for undifferentiated chest pain in the ED. The TIMI score is the simplest and was validated specifically in ACS trial populations, making it quick to apply at the bedside.
Can this calculator be used for STEMI patients?
No. This score applies only to unstable angina and NSTEMI. There is a separate TIMI Risk Score for STEMI that uses entirely different variables (age, blood pressure, heart rate, Killip class, and others) and predicts 30-day mortality rather than 14-day event rates. Use the appropriate score for each diagnosis.