UA/NSTEMI Risk Stratification • Antman et al.
Risk Triage Ready
Complete clinical profile to estimate adverse event probability.
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
Clinical Utility
Prognostication of patients with Unstable Angina (UA) or Non-ST Elevation Myocardial Infarction (NSTEMI).
Risk stratification for all-cause mortality, MI, or severe ischemia requiring urgent revascularization within 14 days.
Decision support for determining the necessity of an early invasive strategy.
Required for Calculation
The score is designed for patients presenting with symptoms suggestive of Acute Coronary Syndrome (ACS). Use in other populations is not validated.
How it Works
Point Distribution (1 pt each)
Age ≥ 65 years
≥ 3 Traditional Risk Factors (HTN, DM, Smoking, Family History, Hyperlipidemia)
Known CAD (Prior coronary stenosis ≥ 50%)
ASA use in the last 7 days
Severe Angina (≥ 2 episodes in last 24 hours)
ST Deviation ≥ 0.5 mm
Positive Cardiac Biomarkers (Troponin or CK-MB)
Risk Table (14-Day Endpoint)
| 0–1 Points | 4.7% (Low) |
| 2 Points | 8.3% (Low) |
| 3 Points | 13.2% (Intermediate) |
| 4 Points | 19.9% (Intermediate) |
| 5 Points | 26.2% (High) |
| 6–7 Points | 40.9% (High) |
Clinical Pearls
The Aspirin Paradox
ASA use is a risk factor because developing ACS while already on aspirin indicates "prevention failure." This suggests more aggressive thrombus formation or more extensive atherosclerotic burden.
Bedside Utility
While the GRACE score is more accurate for long-term survival, the TIMI score remains the gold standard for immediate, bedside triage because it does not require complex software or renal function data.
Next Steps
Management Pathways
01
Score 0–2: Consider ischemia-guided (conservative) strategy with predischarge stress testing.
02
Score ≥ 3: High-benefit group for early invasive strategy (Angiography within 24–48 hours).
03
Score ≥ 5: High-risk cohort; consider urgent angiography and optimized antiplatelet therapy.
The Evidence
Primary Derivation
The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making.
Antman EM et al. • JAMA.. 2000;Validated across the TIMI 11B and ESSENCE trials involving over 7,000 patients.
Origins & History
The TIMI Study Group
Established at Brigham and Women's Hospital, the Thrombolysis in Myocardial Infarction (TIMI) group has led cardiac trials for decades under the leadership of pioneers like Dr. Eugene Braunwald.
Legacy
The UA/NSTEMI score was created to provide a simple, additive tool that shifted clinical focus from guessing risk to objective statistical probability.
Last Comprehensive Review: 2026-07-17