HCM Risk SCD Calculator

HCM Risk-SCD Equation:

\[ \text{Probability (\%)} = 1 - 0.998^{\exp(\text{Prognostic Index})} \] \[ \text{Prognostic Index} = 0.15939858 \times \text{MWT} - 0.00294271 \times \text{MWT}^2 + 0.0259082 \times \text{LAS} + 0.00446131 \times \text{MLVOTG} + 0.4583082 \times \text{FHSCD} + 0.82639195 \times \text{NSVT} + 0.71650361 \times \text{US} - 0.01799918 \times \text{Age} \]

Maximum Wall Thickness (MWT):

Left Atrial Size (LAS):

Maximum LVOT Gradient (MLVOTG):

mm Hg

Age:

years

Family History of SCD (FHSCD):

Non-Sustained VT (NSVT):

Unexplained Syncope (US):

5-Year Risk of Sudden Cardiac Death:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the HCM Risk-SCD Calculator?

The HCM Risk-SCD Calculator estimates the 5-year risk of sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM). It uses seven clinical variables to provide a personalized risk assessment.

2. How Does the Calculator Work?

The calculator uses the HCM Risk-SCD equation:

Where:

\( \text{MWT} \) — Maximum wall thickness (mm)
\( \text{LAS} \) — Left atrial size (mm)
\( \text{MLVOTG} \) — Maximum LVOT gradient (mm Hg)
\( \text{FHSCD} \) — Family history of SCD (0 or 1)
\( \text{NSVT} \) — Non-sustained VT (0 or 1)
\( \text{US} \) — Unexplained syncope (0 or 1)
\( \text{Age} \) — Age in years

Explanation: The equation combines anatomical, hemodynamic, and clinical risk factors to estimate SCD risk in HCM patients.

3. Importance of Risk Calculation

Details: Accurate risk stratification is crucial for identifying HCM patients who may benefit from ICD implantation for primary prevention of SCD.

4. Using the Calculator

Tips: Enter all required parameters. MWT and LAS should be from echocardiographic measurements. MLVOTG is the peak gradient at rest or with provocation.

5. Frequently Asked Questions (FAQ)

Q1: What is considered high risk?
A: Generally, ≥6% 5-year risk is considered high risk for SCD in HCM patients.

Q2: How was this model validated?
A: The model was developed and validated in large international HCM cohorts.

Q3: Should this replace clinical judgment?
A: No, this calculator should be used as part of a comprehensive clinical assessment.

Q4: What about pediatric patients?
A: This calculator is validated for patients ≥16 years old.

Q5: How often should risk be reassessed?
A: Risk should be reassessed periodically, especially with new symptoms or changes in clinical status.