Guides ACS management pathways with TIMI/GRACE scoring and intervention timing. Use when managing STEMI/NSTEMI, risk-stratifying ACS, or coordinating cath lab activation.
Guides ACS management pathways with TIMI/GRACE scoring and intervention timing.
Acute coronary syndromes (ACS) encompass STEMI, NSTEMI, and unstable angina — together representing the most time-critical diagnoses in cardiology. Door-to-balloon time of ≤ 90 minutes for STEMI remains a national quality benchmark. For NSTEMI, the GRACE score drives timing of invasive strategy (immediate, early, or delayed), and misclassification directly impacts mortality. The 2021 ACC/AHA Guideline for Coronary Artery Revascularization and 2014 AHA/ACC NSTE-ACS guideline define evidence-based treatment algorithms that must be followed precisely.
Errors in ACS management — delayed cath lab activation, failure to administer antiplatelet loading, or inappropriate discharge of an unstable patient — carry among the highest malpractice liability in emergency cardiology.
ACS Diagnostic Criteria:
| Type | ECG | Troponin | Clinical |
|---|---|---|---|
| STEMI | ST elevation meeting criteria or new LBBB | Elevated (confirms but do not wait for results) | Chest pain/anginal equivalent |
| NSTEMI | ST depression, T-wave inversion, or non-diagnostic | Elevated above 99th percentile URL with rise/fall pattern | Ischemic symptoms |
| Unstable angina | May be normal or show ischemic changes | Normal (serial) | New-onset, crescendo, or rest angina |
TIMI Risk Score for NSTE-ACS (0–7 points):
| Factor | Points |
|---|---|
| Age ≥ 65 | 1 |
| ≥ 3 CAD risk factors (family Hx, HTN, DM, hyperlipidemia, smoking) | 1 |
| Known CAD (≥ 50% stenosis) | 1 |
| ASA use in prior 7 days | 1 |
| ≥ 2 anginal episodes in prior 24 hours | 1 |
| ST deviation ≥ 0.5 mm | 1 |
| Elevated cardiac biomarker | 1 |
| Score | 14-day Death/MI/Urgent Revasc Risk |
|---|---|
| 0–2 | Low (< 8.3%) |
| 3–4 | Intermediate (13–20%) |
| 5–7 | High (26–41%) |
GRACE Score (6-month mortality post-ACS): Variables: age, HR, SBP, creatinine, Killip class, cardiac arrest at admission, ST deviation, elevated cardiac enzymes.
Time-Critical Benchmarks:
Initial STEMI Medications (Concurrent with Cath Lab Activation):
Killip Classification (Acute HF Severity in MI):
| Class | Findings | In-Hospital Mortality |
|---|---|---|
| I | No HF signs | 6% |
| II | Rales, S3, JVD | 17% |
| III | Pulmonary edema | 38% |
| IV | Cardiogenic shock | 81% |
Invasive Strategy Timing Based on Risk:
| Timing | Criteria |
|---|---|
| Immediate (< 2 hours) | Hemodynamic instability, refractory angina, sustained VT/VF, acute HF |
| Early (< 24 hours) | GRACE > 140, troponin rise/fall, new ST changes |
| Delayed (25–72 hours) | GRACE 109–140, diabetes, eGFR < 60, LVEF < 40%, prior PCI/CABG |
| Ischemia-guided (selective) | Low risk: TIMI 0–2, GRACE < 109, troponin negative, no recurrent symptoms |
Medical Therapy for NSTE-ACS:
Discharge Medication Checklist (ABCDE):
Risk Factor Targets Post-ACS:
Mechanical Complications of MI (typically days 3–7):
Arrhythmic Complications: