The Heart Score (Heart Attack Risk Score)
Acute coronary syndromes (ACS) are a common, sometimes difficult to diagnose spectrum of diseases occurring after abrupt reduction or complete cessation in blood flow through a coronary artery which causes ischemic necrosis of muscles of the heart. Given the diagnostic challenge involved in decision making, it is sensible for emergency physicians to have an approach to prognosticate patients with possible ACS. Multiple prediction models have been developed to help identify patients at increased risk of adverse outcomes. The Heart Score is the first model to be derived, validated, and undergo clinical impact studies in emergency department (ED) patients with possible ACS.
Based on clinical experience and interpretation of relevant medical literature, a group of physicians at a small community based hospital in the Netherlands postulated, that, patient history, ECG abnormalities, higher age, multiple risk factors for coronary artery disease, and elevated cardiac troponin levels could be predictors of major adverse cardiac events (MACE). These represent the five elements of the Heart Score. The Heart Score (heart attack risk score) is a scoring system designed to identify the chance of ischemic heart disease as a possible underlying cause of patients coming to the emergency room with chest pain and to stratify their risk. The risk factors the calculator takes into account and their weightage (in points) in the final score include:
Patient history:
- Highly suspicious (2)
- Moderately suspicious (1)
- Mildly suspicious (0)
ECG:
- Significant ST elevation or depression (2)
- Non specific repolarisation changes (1)
- Normal (0)
Age:
- Equal or higher than 65 (2)
- Between 45 and 65 (1)
- Less than 45 (0)
Risk factors (Hypercholesterolemia, hypertension, diabetes, smoking, obesity)
- More than 3 risk factors or atherosclerosis history (2)
- 1 or 2 risk factors are present (1)
- No risk factors (0)
Troponin (protein resulting from cardiac muscle death)
- 3 times higher than normal or more (2)
- 1 to 3 times higher than normal (1)
- Less than normal (0)
Interpretation of the Heart Risk Score.
The heart score could vary between 0 to 10. Scores close to 0 mean a low risk and scores close to 10 indicate a high risk of major cardiac events.
Recommendation based on the Heart Risk Score.
0 – 3 Low (1.7%) Discharge can be an option.
4 – 6 Intermediate (20.3%) Clinical observation and further investigations.
7 – 10 High (72.2%) Immediate invasive treatment
The Heart Score was developed in the Netherlands in 2008 by Six, Backus, and Kelder as a rapid diagnostic and risk stratification tool for patients presenting to the emergency department with acute chest pain. This decision tool has gained popularity over the years for several reasons.
They include, ease of application, the ready availability of the factors / variables under consideration, the focus on the short term outcome, appropriate for the emergency department management, and the identification of three discrete sub-populations (low-, moderate-, and high-risk) of patients suspected of ACS.
Suspected ACS patients in the emergency department are evaluated with a standard history and physical examination and further bedside and laboratory evaluation. Based upon five different variables, a score is calculated. The factors considered in the scoring system include history (H), 12-lead electrocardiogram (ECG; E), age (A), risk factors (R), and troponin (T).
Scores range from 0 to 2 in each of these five categories, with the lowest possible score of 0 and the highest possible score of 10. Low-risk patients (a score of 3 or less) were found to have a low (1.7%) risk for cardiac events. These low-risk patients can be categorized as appropriate and safe for discharge from the emergency room without additional cardiac evaluation or inpatient admission into the hospital.
A higher score is associated with an increased MACE rate and additional evaluation and/or intervention is called for. In these two higher score categories, two distinct subpopulations are noted, including the following MACE rates: moderate-risk, with a score of 4–6, MACE rate of approximately 12–17% and the consideration of observation and further testing; and high-risk, with a score of 7–10, MACE rate of approximately 50–65%, and the consideration of definite urgent or emergent intervention. After its initial descriptive use, the heart score has been validated in many clinical trials.