TIMI Risk Score for STEMI Calculator

How does this TIMI risk score for STEMI calculator work?

This is a cardiovascular heart tool that assesses the risk of ischemic events in patients withy symptoms consistent with ACS acute coronary syndrome, angina, ST elevation myocardial infarction.

It is known that patients undergoing a ST elevation myocardial infarction are at high risk of complications, therefore a tool like TIMI score, will allow the medical professional to determine the emergency procedure that is most beneficial, also because the score is based on thrombolytic outcomes, taking into account the high risk scenarios. The factors used in the model are described below:

■ Age category: < 65 years [0 points]; 65-74 [2 points]; ≥ 75 [3 points] – taking into consideration that a higher age is consistent with a higher risk for MI.

■ Systolic BP < 100 mmHg [3 points] – hypertension or high blood pressure accompanied by other conditions in one of the risk factors in ACS.

■ Heart Rate > 100 bpm [2 points] – increased heart rate can suggest a heart condition

■ DM or hypertension or angina [1 point] – symptoms of acute coronary syndrome

■ Anterior ST elevation or LBBB (Left Bundle Branch Block) [1 point] – ECG evidence of myocardial infarction

■ Killip class II-IV [2 points] – this is suggestive for individuals presenting either rales or crackles, elevated jugular venous pressure or even acute pulmonary edema

■ Weight < 147.7 lbs / 67 kg [1 point] – depending on patient, increased weight and no physical activity might become cardiovascular risk factors

■ Time to Treatment > 4 hours [1 point] – the duration of symptoms before the patient had access to medical treatment, relevant in determining outcome

Interpreting the risk score result

The result obtained in this TIMI risk score for STEMI calculator permits an informed medical decision in the following steps, usually thrombolysis or percutaneous coronary intervention, based on the level of mortality risk of each patient. Once the scores is summed in the previous step, the heart risk stratification tool will search and display the mortality risk in percentage, according to the following table:

STEMI medical implications

This is one of the types of myocardial infarction and it is characteristic by the ST elevation present in electrocardiogram ECG testing. It is also known as transmural or Q wave myocardial infarction and occurs when a coronary artery is suddenly blocked and blood flow is diminished. The area of the heart supplied by the artery becomes infracted, meaning it doesn’t receive blood to nourish it and dies.

The term ST elevation suggests that a relatively large amount of heart muscle has been damaged, due to the said blood flow blockage in which the coronary artery is occluded.

The other type non STEMI is less severe because usually arteries are only partially blocked, unlike STEMI in which the blockage is almost complete. The main differences between these two types of AMI can be observed through ECG, elevation vs. non elevation.

Reference

Morrow DA, Antman EM, Charlesworth A, Cairns R, Murphy SA, de Lemos JA, Giugliano RP, McCabe CH, Braunwald E. (2000) 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; 102(17):2031-7.