TIMI Risk Score Calculator (UA/NSTEMI)

How to Use This Calculator

1. Answer each of the 7 yes/no TIMI variables.
2. Your TIMI score (0-7), 14-day MACE risk, and management strategy update instantly.
3. Use the Risk Stratification tab for clinical strategy and antiplatelet guidance.
4. Professional tier includes high-sensitivity troponin integration and HEART score comparison.

Formula

Example

Frequently Asked Questions

• What is the TIMI score and how does it differ from GRACE? ▼
  The TIMI (Thrombolysis in Myocardial Infarction) risk score for UA/NSTEMI is a seven-variable binary scoring tool developed by Antman et al. and published in JAMA in 2000. Each variable is scored 0 or 1, giving a total from 0 to 7. The seven factors are: age ≥65, presence of ≥3 traditional CAD risk factors (family history, hypertension, hyperlipidemia, diabetes, current smoking), known coronary artery disease with ≥50% stenosis on prior angiography, aspirin use within the preceding 7 days (a surrogate for aspirin-refractory ischemia), ≥2 anginal episodes within the prior 24 hours, ST deviation ≥0.5 mm on the presenting ECG, and positive cardiac biomarkers. The score was validated in the TIMI IIIB trial and subsequently in multiple external cohorts. GRACE, by contrast, uses continuous physiological variables (actual heart rate, blood pressure, creatinine) producing a continuously varying score, and has demonstrated superior discrimination for mortality prediction (c-statistic ~0.72-0.82 for GRACE vs ~0.62-0.68 for TIMI). Despite GRACE's superiority in head-to-head studies, TIMI remains widely used clinically because of its simplicity and because it requires no vital sign measurements or lab values.
• What constitutes a high TIMI score and what should be done? ▼
  A TIMI score of 5-7 is classified as high risk and is associated with a 14-day rate of major adverse cardiac events (MACE — defined as all-cause death, new or recurrent MI, or need for urgent revascularization) of approximately 26-41%. Patients in this range have the greatest absolute benefit from an early invasive strategy, meaning coronary angiography within 24-48 hours followed by revascularization if appropriate anatomy is found. For high TIMI patients (5-7), current AHA/ACC NSTEMI guidelines recommend: dual antiplatelet therapy with aspirin plus ticagrelor (preferred over clopidogrel based on PLATO trial data showing superior outcomes with ticagrelor in NSTEMI), parenteral anticoagulation (unfractionated heparin or fondaparinux as first-line), consideration of GP IIb/IIIa inhibitor in select cases with high thrombus burden or delayed angiography, and early invasive strategy over conservative management. A TIMI score of 3-4 is intermediate risk (~13-20% MACE), and while an early invasive strategy is generally favored, ischemia-guided management may be considered in select patients. TIMI 0-2 is low risk (~5-8% MACE), where conservative management with provocative ischemia testing is acceptable.
• How is TIMI used alongside high-sensitivity troponin? ▼
  High-sensitivity troponin (hsTroponin) has transformed the biomarker landscape in ACS since its introduction in ESC guidelines, and its integration with TIMI reflects this evolution. In the original TIMI derivation, positive "cardiac markers" referred to conventional troponin or CK-MB, which required 6-12 hour serial testing. High-sensitivity troponin assays detect myocardial injury at concentrations 10-100 times lower than conventional assays, enabling 0/1-hour and 0/2-hour rapid rule-out protocols. When hsTroponin is the biomarker used, the TIMI "positive markers" variable is answered based on hsTroponin results. Importantly, even a "rule-out" on the rapid hsTn protocol does not mean zero risk — TIMI and clinical context remain essential for the rule-out group. Studies evaluating hsTroponin in conjunction with TIMI show that a TIMI score of 0 or 1 plus negative hsTn at 0 and 1 hour effectively identifies a large group of patients (30-40% of ED chest pain presentations) who can be safely discharged without further testing, reducing unnecessary admissions and costs.
• Can TIMI predict long-term outcomes beyond 14 days? ▼
  The TIMI score was specifically derived and validated to predict 14-day major adverse cardiac events (MACE) in UA/NSTEMI, and this remains its primary and best-validated use case. Its predictive ability at 30 days is also reasonable, as confirmed by secondary analyses of the TIMI IIIB and ESSENCE trials, but the score was not designed for long-term prediction. Multiple studies have evaluated TIMI at 30 days, 6 months, and 1 year; predictive ability generally diminishes over longer time horizons because acute risk factors (cardiac enzyme elevation, acute ST changes) contribute less to chronic risk, while traditional cardiovascular risk factors (age, diabetes, hypertension) become more dominant. For longer-term secondary prevention risk, tools like the ASCVD Pooled Cohort Equations or SMART score are more appropriate. Clinically, TIMI is best thought of as an acute triage tool answering the question "how urgently should this patient be evaluated and treated right now?" rather than a chronic risk predictor. For ongoing risk stratification post-ACS, the combination of LV function assessment, ischemia testing, and risk factor optimization is more relevant than the original TIMI score.
• Why does TIMI not include vital signs like GRACE? ▼
  The TIMI UA/NSTEMI score was intentionally designed using only binary yes/no variables to maximize simplicity and bedside applicability, a deliberate design choice by the TIMI Study Group. At the time of derivation (late 1990s), the goal was a score clinicians could calculate mentally in the emergency department without calculators or nomograms. By using only binary variables, TIMI avoids the need to measure and record precise vital signs and laboratory values at the moment of scoring — a significant practical advantage in emergency triage settings. The tradeoff is reduced discriminative ability: vital signs and laboratory values contain substantial prognostic information in continuous form. A patient with a systolic BP of 85 mmHg carries much greater risk than one with SBP 140 mmHg, but TIMI does not distinguish between them. GRACE captures this gradient by incorporating actual measured values with weighted point assignments. This design philosophy explains why GRACE outperforms TIMI in c-statistic comparisons: the information value lost through dichotomization in TIMI is substantial. Modern risk scores like the HEART score (used in ED chest pain evaluation) and the ESC 0/1h rapid rule-out protocol have moved toward incorporating continuous values, reflecting the clinical community's acceptance of slightly more complex but more accurate tools.

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