timi_risk_index: TIMI Risk Index (TRI) for STEMI

Description

Calculates the TIMI Risk Index for patients with ST-Elevation Myocardial Infarction (STEMI). The index is a continuous variable derived from heart rate, systolic blood pressure, and age, which predicts 30-day mortality. It stratifies patients into five risk groups based on data from the InTIME II trial.

Usage

timi_risk_index(heart_rate, systolic_bp, age)

Value

A list containing:

TIMI_Risk_Index: The calculated index score.
Risk_Group: The risk quintile (Group I-V).
Est_30_Day_Mortality: Estimated 30-day mortality percentage.

Arguments

heart_rate: Numeric. Heart rate in beats per minute (bpm).
systolic_bp: Numeric. Systolic blood pressure in mmHg.
age: Numeric. Patient age in years.

Details

The formula used is: $$TRI = \frac{Heart Rate \times (Age/10)^2}{Systolic BP}$$ Risk Groups (30-day mortality):

Group I (< 12.5): 0.8%
Group II (12.5 - <17.5): 1.9%
Group III (17.5 - <22.5): 3.3%
Group IV (22.5 - 30): 7.3%
Group V (> 30): 17.4%

References

Morrow DA, Antman Giugliano RP, et al. A simple bedside risk score for early risk stratification in patients with acute coronary syndromes. Circulation. 2000;102(suppl II):II-203. Morrow DA, Antman EM, Charlesworth A, et al. TIMI risk score for ST-elevation myocardial infarction: A convenient, bedside, clinical score for risk assessment at presentation: An intravenous nPA for treatment of infarcting myocardium early II trial substudy. Circulation. 2000;102(17):2031-2037. doi:10.1161/01.cir.102.17.2031

Examples

Run this code


# Example 1: High Risk
# HR 100, SBP 100, Age 75
# TRI = (100 * (7.5^2)) / 100 = 56.25
timi_risk_index(100, 100, 75)

# Example 2: Low Risk
# HR 60, SBP 140, Age 50
# TRI = (60 * (5.0^2)) / 140 = (60 * 25) / 140 = 10.7
timi_risk_index(60, 140, 50)

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