TIMI Risk Score for NSTEMI

TIMI Risk Score

A Practical Guide for Clinical Use

What is TIMI Risk Score?

The TIMI (Thrombolysis in Myocardial Infarction) Risk Score is a bedside clinical scoring system developed to estimate the risk of death and ischemic events in patients with:

• Unstable Angina (UA) / NSTEMI

• STEMI

It helps in: • Early risk stratification

• Guiding invasive vs conservative strategy

• Predicting 14-day or 30-day outcomes

Developed from the TIMI Study Group trials.

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1️⃣ TIMI Risk Score for UA / NSTEMI

Developed from the TIMI 11B Trial.

Each variable = 1 point (Total = 0–7)

Variable Criteria

Age ≥ 65 years 1

≥3 CAD risk factors (HTN, DM, smoker, FHx, dyslipidemia)

Known CAD ≥50% stenosis

Aspirin use in past 7 days 1

≥2 angina episodes in 24 hrs 1

ST deviation ≥0.5 mm 1

Elevated cardiac biomarkers Troponin positive

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Risk Interpretation (14-day risk of death/MI/urgent revascularization)

Score Risk

0–1 ~5%

2 ~8%

3 ~13%

4 ~20%

5 ~26%

6–7 ~41%

Clinical Use

• Score ≥3 → Early invasive strategy preferred

• Score 0–2 → Conservative management may be considered

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2️⃣ TIMI Risk Score for STEMI

Developed from the InTIME II Trial.

Variables (Weighted Score System)

Variable Points

Age 65–74 2

Age ≥75 3

SBP <100 mmHg 3

HR >100 bpm 2

Killip class II–IV 2

Weight <67 kg 1

Anterior MI or LBBB 1

Time to treatment >4 hrs 1

DM/HTN/Angina history 1

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Risk Interpretation (30-day mortality)

Score Mortality

0 0.8%

1 1.6%

2 2.2%

3 4.4%

4 7.3%

5 12%

6 16%

7 23%

≥8 35%

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Why TIMI Score Still Matters

✔ Simple bedside calculation

✔ No calculator required

✔ Validated in multiple cohorts

✔ Useful in resource-limited settings

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TIMI vs GRACE Score

Feature TIMI GRACE

Complexity Simple Complex

Variables 7 (NSTEMI) 8

Accuracy Good Superior

Guideline preference Acceptable Preferred in ESC

GRACE score derived from the GRACE Registry.

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Exam Pearls (Cardiology / FCPS / MD)

• TIMI ≥3 (UA/NSTEMI) → Early invasive strategy

• STEMI TIMI >8 → Very high mortality

• TIMI does NOT replace clinical judgment

• GRACE preferred in current ESC guidelines

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Limitations

• Developed in fibrinolysis era

• Does not incorporate renal function

• Less accurate than GRACE

• Limited precision in contemporary PCI era

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Bottom Line

TIMI Risk Score is a simple, bedside, rapid stratification tool in ACS.

While GRACE is more accurate, TIMI remains practical and exam-relevant.