TIMI UA/NSTEMI
Calculate TIMI risk score for UA/NSTEMI: 7 criteria predict 14-day death, MI, or urgent revascularization risk. Free online clinical risk assessment tool for healthcare professionals.
About This Calculator
The TIMI (Thrombolysis In Myocardial Infarction) risk score for UA/NSTEMI is a clinically validated bedside scoring system that predicts the 14-day risk of adverse cardiac events — all-cause mortality, new or recurrent myocardial infarction, and severe recurrent ischemia requiring urgent revascularization — in patients presenting with unstable angina (UA) or non-ST-elevation myocardial infarction (NSTEMI). Developed by Antman et al. and published in JAMA in 2000, the score was derived from the TIMI 11B trial (n=1,959) and validated in the ESSENCE trial (n=3,171) and the TIMI III Registry (n=2,765), making it one of the most extensively validated risk stratification tools in cardiology.
The TIMI UA/NSTEMI score comprises 7 equally-weighted binary criteria, each contributing 1 point: age 65 years or older; three or more risk factors for coronary artery disease (diabetes, hypertension, hypercholesterolemia, family history of premature CAD, or current smoking); known coronary artery disease with angiographic stenosis of at least 50%; aspirin use within the past 7 days; severe angina defined as at least 2 anginal episodes in the preceding 24 hours; ST-segment deviation of 0.5 mm or more on the presenting electrocardiogram; and elevated serum cardiac biomarkers (troponin I or T, or CK-MB above the upper normal limit). The total score ranges from 0 to 7, and the corresponding 14-day event rate ranges from 4.7% (scores 0-1) to 40.9% (scores 6-7).
Regional Notes
US: The ACC/AHA guidelines for UA/NSTEMI recommend TIMI risk stratification to guide the timing of invasive management. Scores 0-2 suggest conservative management, while scores 3-7 suggest early invasive strategy with angiography within 24-48 hours. The use of GP IIb/IIIa inhibitors is recommended for high-risk patients undergoing early PCI.
UK: NICE guidelines (NG185) for acute coronary syndromes recommend the TIMI score as part of initial risk assessment in UA/NSTEMI. Patients with TIMI scores of 3 or higher are recommended for coronary angiography within 72 hours, with those at highest risk considered for immediate angiography. The NHS advocates systematic use of validated risk scores in all ACS admissions.
India: The TIMI UA/NSTEMI score is widely adopted across Indian cardiology centers and has been validated in the Indian ACS registry. Given the higher prevalence of premature CAD and diabetes in the Indian population, the score's inclusion of CAD risk factors is particularly relevant. Many Indian hospitals incorporate TIMI scoring into standard ACS protocols for triage and management decisions.
Frequently Asked Questions
What is the TIMI risk score for UA/NSTEMI?
The TIMI (Thrombolysis In Myocardial Infarction) risk score for UA/NSTEMI is a validated clinical scoring system that predicts the 14-day risk of all-cause mortality, new or recurrent myocardial infarction, and severe recurrent ischemia requiring urgent revascularization in patients with unstable angina or non-ST-elevation myocardial infarction. It uses 7 equally-weighted criteria — age over 65, three or more CAD risk factors, known coronary stenosis, aspirin use, severe angina, ST-segment deviation, and elevated cardiac biomarkers — to calculate a total score from 0 to 7.
How is the TIMI UA/NSTEMI score calculated?
The TIMI UA/NSTEMI score assigns 1 point for each of 7 criteria: age 65 years or older; three or more risk factors for coronary artery disease (diabetes, hypertension, hypercholesterolemia, family history, smoking); known CAD with stenosis at least 50%; aspirin use in the past 7 days; severe angina with at least 2 episodes within 24 hours; ST-segment deviation of at least 0.5 mm on ECG; and positive cardiac biomarkers (elevated troponin or CK-MB). The total score ranges from 0 to 7 points.
What do different TIMI UA/NSTEMI scores mean?
Score 0-1: 4.7% risk of adverse events within 14 days (low risk). Score 2: 8.3% risk (moderate risk). Score 3: 13.2% risk (moderate risk). Score 4: 19.9% risk (high risk). Score 5: 26.2% risk (high risk). Score 6-7: 40.9% risk (very high risk). Higher scores indicate progressively greater risk of death, myocardial infarction, or urgent revascularization, guiding the intensity of medical management and the timing of invasive coronary angiography.
Who developed the TIMI risk score for UA/NSTEMI?
The TIMI risk score for UA/NSTEMI was developed by Antman et al. and published in JAMA in August 2000. It was derived from the TIMI 11B trial and validated in the ESSENCE trial and the TIMI III Registry, with over 7,000 patients included across these studies. The score has been externally validated in diverse international populations and remains one of the most widely used risk stratification tools for acute coronary syndrome.
Can this calculator replace a doctor's assessment?
No. This calculator is for educational and reference purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. The TIMI score is an adjunctive risk stratification tool that should be used alongside comprehensive clinical assessment by a qualified healthcare provider, including physical examination, serial ECGs, and laboratory testing. Always consult a physician for any medical decisions.
What are the seven risk factors for the TIMI UA/NSTEMI score?
The seven TIMI UA/NSTEMI risk factors are: 1) age 65 years or older; 2) three or more risk factors for coronary artery disease (diabetes, hypertension, hypercholesterolemia, family history of CAD, or current smoking); 3) known coronary artery disease with stenosis of at least 50%; 4) acetylsalicylic acid (aspirin) use in the past 7 days; 5) severe angina with at least 2 episodes in the preceding 24 hours; 6) ST-segment deviation of at least 0.5 mm on the presenting electrocardiogram; and 7) elevated serum cardiac biomarkers (troponin I or T, or CK-MB).
How does TIMI UA/NSTEMI differ from the TIMI STEMI score?
The TIMI UA/NSTEMI score is designed for patients with unstable angina or non-ST-elevation MI, using 7 equally-weighted binary criteria for a 0-7 score predicting 14-day risk. The TIMI STEMI score is specifically for ST-elevation MI, uses 8 weighted criteria (Killip class, time to treatment, weight, etc.) for a 0-14 score predicting 30-day mortality. They serve different patient populations and should not be used interchangeably.
Is the TIMI UA/NSTEMI score used worldwide?
Yes, the TIMI UA/NSTEMI risk score is validated and used internationally in the US, UK, India, and across Europe and Asia. The ACC/AHA and ESC guidelines both recommend TIMI risk stratification for UA/NSTEMI patients to guide the decision between early invasive versus conservative management strategies. In India, it has been validated in the Indian ACS registry and is widely used in cardiology centers.