Medical Book

LANGUAGE
English Español 中文 Українська
Search

Showing results for: Array

    Medical Book

    LANG
    English Español 中文 Українська
    TIMI
    Home > Parameters

    TIMI

    TIMI risk index for myocardial infarction: formula from heart rate, age and systolic pressure, and prediction of 30-day mortality.

    The TIMI risk index (TRI) is a simple score for the rapid initial assessment of patients with acute myocardial infarction. It combines three items available at first contact, before laboratory tests: heart rate, systolic blood pressure and age. It was developed in 2001 by the TIMI (Thrombolysis In Myocardial Infarction) study group in patients with ST-elevation myocardial infarction. Higher values mean a higher risk of death within 30 days.

    Acute coronary syndromeRisk stratificationTriage
    FormulaHR × (age / 10)² / SBP
    Predicts30-day mortality
    Discriminationc-statistic ≈ 0.78
    ExampleHR 90, age 70, SBP 120 → 36.8

    Calculation

    TRI = heart rate (beats/min) × [age (years) / 10]² / systolic blood pressure (mmHg)

    Example: a 60-year-old with heart rate 70 and systolic pressure 140: 70 × 36 / 140 = 18. A 70-year-old with heart rate 90 and pressure 120: 90 × 49 / 120 ≈ 36.8, a much higher risk.

    How the three components affect the TIMI risk index: older age raises it strongly because age is squared, faster heart rate raises it, and lower systolic pressure raises it What raises the TIMI risk index Age ↑ (squared) 60 → 70 years: index × 1.36 Heart rate ↑ 70 → 100 beats/min: index × 1.43 Systolic pressure ↓ 140 → 100 mmHg: index × 1.4 Fast heart rate with low pressure reflects poor pump function or shock; age is the strongest single factor.
    Figure 1. Effect of each component on the TIMI risk index.

    Clinical significance

    In the InTIME II trial population, 30-day mortality rose steadily with increasing TRI, and the index discriminated risk nearly as well as the more complex TIMI risk score for STEMI. Because it needs only vital signs and age, it can be calculated by ambulance staff or at triage to prioritise transfer to a centre capable of coronary intervention. It does not replace the ECG, troponin measurement or full clinical assessment, and it is not a diagnostic test for infarction.

    Seek emergency care

    Chest pain or pressure lasting more than a few minutes, especially with breathlessness, sweating, nausea or fainting, requires calling emergency services immediately, whatever the index value.

    References

    1. Morrow DA, Antman EM, Giugliano RP, et al. A simple risk index for rapid initial triage of patients with ST-elevation myocardial infarction: an InTIME II substudy. Lancet. 2001;358:1571–1575.

    This article is for general information and does not replace a consultation with a doctor. Measurements must be interpreted by a physician together with symptoms and other tests.

    Published on 23 April 2024