Standard heart-risk calculators often ask if you have a “family history of heart disease,” but they rarely ask who had it or how young they were. The Inherited Hazard Coefficient (H) changes that.
This formula recognizes that a sibling having a heart attack at 40 is a much stronger “genetic red flag” than a grandparent having one at 80. By calculating your H-score, you can determine if you are in the “Imaging Trap”—where a standard Calcium Score (CAC) might come back as zero even while dangerous “soft” plaque is building up in your arteries.
Example 1: High Inherited Risk (The “Red Flag” Profile)
- The Situation: Your brother had a fatal heart attack at age 42.
- The Inputs: * Relation: 0.5 (Sibling)
- Age: 42
- Severity: 1.5 (Death)
- The Result: A score contribution of 0.0178 from just one relative. If you add a parent with a similar history, your score will quickly exceed 0.05, indicating a high need for advanced imaging like a CCTA.
Example 2: Moderate/Lower Inherited Risk
- The Situation: Your grandfather had a heart attack at age 75 and survived.
- The Inputs: * Relation: 0.25 (Grandparent)
- Age: 75
- Severity: 1.0 (Event/Survival)
- The Result: A score contribution of 0.0033. While still part of your history, the later age and more distant relation suggest that lifestyle and environment may play a larger role than genetics alone.
Interactive Calculator
How to Input Your Data
To get an accurate score, you’ll need to input three values for each affected relative:
- Relation (R): Use 0.5 for immediate family (parents/siblings) and 0.25 for second-degree relatives (grandparents/uncles/aunts).
- Age (A): The age they were when they had their first event or were diagnosed.
- Severity (W): Assign a weight based on the outcome. We recommend:
- 1.0 for a non-fatal event (stent, bypass, or surviving a heart attack).
- 1.5 for a fatal heart attack.
- 2.0 for sudden cardiac death under the age of 50.
Inherited Hazard Calculator
Use this tool to calculate your genetic risk coefficient (H).