Online medical calculator calculates the TIMI risk index by entering the heart rate, age and Systolic Bp values.
A simple calculator to predict 30-day mortality, which has been well validated against a registry of 150,000 STEMI patients, and shown to have a very good discriminatory capacity. It was also validated against a registry of over 300,000 NSTEMI patients. It has been shown to both predict in-hospital and long-term mortality.
Formula
This formula leads to an index that is useful in determining the risk of death and ischemic events. Targeted patients are those who suffer from unstable angina and/or ST elevation MI or non-ST elevation MI. The TIMI score calculator (Thrombolysis In Myocardial Infarction score calculator) serves as a simple tool to determine the 14 day risk of death or major health complications in patients with UA (Unstable Angina) or NSTEMI (Non-ST-segment Elevation Myocardial Infarct). The TIMI score is intended for use only on those who have three or more manifestations of acute coronary syndrome). For patients with STEMI (ST-segment Elevation Myocardial Infarct), there is another scale designed - TIMI score for STEMI calculator. It contains different TIMI score risk factors.
What is the TIMI score?
In an emergency, it's all about evaluating the risk of severe outcomes. Acute coronary syndrome (or ACS for short) is a common disease, contributing massively to hospital admission in the USA and all over the world. Cases of ACS are not equally severe, so, although every patient needs close monitoring, the outcomes vary.
To help doctors spot the patients who are at the highest risk of severe health complications, the TIMI score (Thrombolysis In Myocardial Infarction) was made. The TIMI score is a result of two international, randomized, double-blind trials and was launched in 2000. Since then, it has been validated on thousands of patients in papers (e.g., in this American article) led by the TIMI Study Group. The research has proven that the TIMI score correlates with the risk of the adverse outcome, and is a valuable prognostic tool, and, in addition - a very simple one.
Assessing the TIMI score helps you to find those patients who may benefit from more a aggressive treatment, which implies, e.g., a need for transport to a more specialized hospital or ward.
Using the TIMI risk score calculator
Using the calculator is extremely simple - just select "Yes" next to those conditions that your current patient has. If you need help, hover the mouse cursor over the criteria or check the section below for more complex explanations.
Below the TIMI score calculator, you'll find your result - the likelihood (as a percentage) of major health complications after an episode of unstable angina pectoris or NSTE myocardial infarct. The percent value refers to all of the conditions at once - death, myocardial infarct, and an urgent need for revascularization.
TIMI score - risk factors
There are seven risk factors in the TIMI score calculator.
Age ≥ 65 years;
≥ 3 risk factors for coronary artery disease - these factors include:
- Diabetes;
- Hypercholesterolemia and distorted cholesterol ratios;
- family history of CAD (Coronary Artery Disease);
- Hypertension; or
- Being a current smoker (quitting one minute ago doesn't count - smoking recovery takes time).
- Check this criterion positive if at least three of them are present.
Known CAD with stenosis ≥ 50% - this refers to patients with a history of coronarography. Remember to ask the patient about incidents like myocardial infarction, stent or CABG placement, or prior angina pectoris.
Acetylsalicylic acid use in the past seven days - get a recent medical history with a list of all the drugs the patient is currently taking. Some acetylsalicylic acid medicines are OTCs (Over-The-Counter drugs), don't forget to ask about that.
Severe angina - defined here as at least two episodes in the past 24 hours.
EKG deviations - in this case, we're looking for ST-segment depression (as in ST elevation we would be using another TIMI risk score). Look for changes of at least 0.5 mm (0.5 mV).
Positive cardiac marker - abnormally high levels of cardiac troponin I or T (cTnI or cTnT) or cardiac kinase - myocardial bands (CK-MB) are a bad sign, as they are a sign of heart damage. This parameter is considered the most prognostic of the TIMI score risk factors, and is associated with adverse outcomes.
Acute coronary syndrome is, in most cases, a result of long-lasting and neglected cardiovascular diseases (CVD), like obesity and hypertension. Find out more about CVD risk factors in our CVD 10-year risk calculator, which is based on the long-lasting - and still ongoing - Framingham Heart Study.
© Aleksandra Zając, MD
Example:
A 65 year old lady wants to find her TIMI risk index. Her heart beat is 72 beats per minute and her systolic blood pressure is 160 mm Hg. Calculate TIMI risk index for her.
Given,
Age = 65
Heart beat = 72
Systolic BP = 160 mm Hg
To Find,
TIMI risk index (Thrombolysis in Myocardial Infarction)
Solution
Substitute the given values in the formula,
TIMI Risk Index = heart beat x (age / 10)2 / systolic BP
= 72 x (65 / 10)2 / 160
= 72 x 6.52 / 160
= 72 x 42.25 / 160
= 3042 / 160
= 19.0125
= 19
If TRI < 30, then Low TRI i.e, In-hospital mortality ~ 10% or less
If TRI > 30, then Intermediate / High TRI i.e, In-hospital mortality > 10%
The risk index value is 19 i.e. < 30. Therefore, the patient is in In-hospital mortality ~ 10% or less.
The three variables that are taken into account in the calculation are:
- Patient age in years;
- Heart rate in beats per minute;
- Systolic blood pressure in mmHg.
Interpretation
The result from the above formula is classified in a risk group and awarded the corresponding 24hr, in-hospital and 30-days mortality risk percentages.
| Risk index | Risk group | Mortality risk (24 hr) | Mortality risk (in-hospital) | Mortality risk (30 days) |
|---|---|---|---|---|
| <12.5 | I | 0.2 | 0.6 | 0.8 |
| <12.5 - 17.5 | II | 0.4 | 1.5 | 1.9 |
| <17.5 - 22.5 | III | 1 | 3.1 | 3.3 |
| <22.5 - 30 | IV | 2.4 | 6.5 | 7.3 |
| <>30 | V | 6.9 | 15.8 | 17.4 |
ACS and myocardial infarction
Acute coronary syndrome is a term that characterizes all conditions in which a reduction of blood flow takes place in the coronary arteries. This can be caused by plaque build-up in the arteries (coronary atherosclerosis) which narrows the arteries and prevents blood flow.
These conditions impair heart function and may lead to a sudden stop of the heart, myocardial infarction.
Some of the cardiac risk factors include:
- Age higher than 45 for men and 55 for women;
- High cholesterol;
- Hypertension;
- Diabetes mellitus;
- Sedentarism;
- Family history of cardiac disease.
Most common ACS symptoms include chest pressure (unstable angina) or radiating pain.
Other accompanying symptoms are shortness of breath, dizziness, heartburn, nausea, vomiting or feeling restless.
Left untreated, these symptoms are precursors of a heart attack that is life threatening.
References
- Morrow DA, Antman EM, Charlesworth A, Cairns R, Murphy SA, de Lemos JA, Giugliano RP, McCabe CH, Braunwald E. 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):2031-7.
- Wiviott SD, Morrow DA, Frederick PD, Antman EM, Braunwald E, National Registry of Myocardial Infarction. Application of the Thrombolysis in Myocardial Infarction risk index in non-ST-segment elevation myocardial infarction: evaluation of patients in the National Registry of Myocardial Infarction. J Am Coll Cardiol. 2006; 47(8):1553-8.