The HEART Score for Chest Pain Risk Stratification
The HEART score is a validated clinical decision tool that combines five components—History, ECG, Age, Risk factors, and Troponin—to stratify patients with chest pain into low (0-3 points), intermediate (4-6 points), and high-risk (≥7 points) categories for major adverse cardiac events (MACE), with low-risk patients having <1% risk of 30-day MACE and being eligible for early discharge. 1, 2
Components and Scoring System
The HEART score assigns 0-2 points for each of five elements, creating a total score ranging from 0-10 points 1, 3:
History Component (0-2 points)
- Highly suspicious features (2 points): Retrosternal chest discomfort building gradually over minutes, with radiation to left arm/neck/jaw, associated with dyspnea, nausea, diaphoresis, or lightheadedness 4
- Moderately suspicious (1 point): Features that are concerning but not classic
- Non-suspicious (0 points): Features inconsistent with cardiac origin 3
ECG Component (0-2 points)
- Significant ST-segment depression (2 points): ≥1 mm ST depression or pathological Q waves 3
- Non-specific repolarization abnormalities (1 point): ST changes or T-wave inversions that are borderline 3
- Normal ECG (0 points): No ischemic changes 3
Age Component (0-2 points)
Risk Factors Component (0-2 points)
- ≥3 risk factors or history of atherosclerotic disease (2 points): Including diabetes, hypertension, hyperlipidemia, smoking, family history of premature CAD, or known coronary disease 1, 4
- 1-2 risk factors (1 point) 3
- No risk factors (0 points) 3
Troponin Component (0-2 points)
Risk Stratification and Clinical Decision-Making
Low-Risk Group (HEART Score 0-3)
Patients with scores 0-3 have <1% risk of 30-day MACE and should be discharged from the emergency department without extensive cardiac workup. 1, 2, 5 In validation studies, only 0.99% of low-risk patients experienced MACE within 6 weeks 3. These patients require proper outpatient follow-up but do not need admission or stress testing 5.
Intermediate-Risk Group (HEART Score 4-6)
Patients with scores 4-6 have an 11.6% risk of MACE and require serial troponin measurements and observation 3. The HEART Pathway combines the modified HEAR score (History, ECG, Age, Risk factors without initial troponin) of 0-3 with serial troponins at 0 and 2-3 hours; patients must have both a HEAR score ≤3 AND negative serial troponins to qualify for early discharge. 6 Those with HEAR scores ≥4 or elevated troponins require admission for stress testing or angiography 6.
High-Risk Group (HEART Score ≥7)
Patients with scores ≥7 have a 65.2% risk of MACE and require immediate cardiology consultation with consideration for invasive coronary angiography 3, 2. These patients should be admitted for urgent evaluation 1.
Performance Characteristics
The HEART score demonstrates excellent discriminatory power with a sensitivity of 95.9% and specificity of 44.6% for MACE when using a threshold of ≥4 2. For mortality prediction specifically, the sensitivity is 95.0%, and for myocardial infarction, it reaches 97.5% 2. The area under the curve is 0.874, indicating strong predictive accuracy 5. The HEART score outperforms the TIMI score, which has only 87.8% sensitivity at its low-risk threshold 2.
Integration with High-Sensitivity Troponin Testing
When using high-sensitivity troponin assays, the American College of Emergency Physicians recommends combining the HEART score with serial measurements at 0 and 2 hours for accelerated diagnostic protocols. 6, 1 The 0/1h and 0/2h algorithms are superior to the 0/3h algorithm, which has been downgraded due to reduced sensitivity for MI 6. Patients must have both a low HEART score AND negative serial troponins to qualify for safe early discharge 6.
Critical Pitfalls to Avoid
The HEART score may be less accurate in very early presenters where troponin elevation hasn't yet occurred, necessitating serial measurements even with initially low scores 1. The subjective nature of the history component introduces variability, and patients with troponin elevations or acute ischemic ECGs can paradoxically have low-risk scores if other components are favorable 6.
Do not rely on a single troponin measurement in patients presenting within 2-3 hours of symptom onset, as up to 26% of patients with acute MI may be on the downslope of the troponin curve and not show significant changes over short intervals 6. Serial ECG changes are crucial when the initial ECG is nondiagnostic 1.
The acceptable miss rate for emergency physicians is 1-2% for 30-day MACE, which the HEART score achieves when properly applied 6, 1.