HCM Sudden Death Risk Calculator

HCM Risk Equation:

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

Max Wall Thickness (MWT):

Left Atrial Size (LAS):

Max LVOT Gradient (MLVOTG):

mm Hg

Family History of SCD (FHSCD):

Non-Sustained VT (NSVT):

Unexplained Syncope (US):

Age:

years

5-Year Risk of Sudden Cardiac Death:

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1. What is the HCM Sudden Death Risk Calculator?

The HCM Sudden Death Risk Calculator estimates the 5-year probability of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM) based on established clinical risk factors.

2. How Does the Calculator Work?

The calculator uses the following equations:

Where:

\( MWT \) — Maximum wall thickness (mm)
\( LAS \) — Left atrial size (mm)
\( MLVOTG \) — Maximum left ventricular outflow tract gradient (mm Hg)
\( FHSCD \) — Family history of sudden cardiac death (0 or 1)
\( NSVT \) — Non-sustained ventricular tachycardia (0 or 1)
\( US \) — Unexplained syncope (0 or 1)
\( Age \) — Patient age in years

Explanation: The equation combines anatomical, hemodynamic, clinical, and family history factors to estimate sudden death risk.

3. Importance of Risk Calculation

Details: Accurate risk stratification is crucial for determining which HCM patients may benefit from ICD implantation for primary prevention of sudden cardiac death.

4. Using the Calculator

Tips: Enter all required parameters accurately. MWT and LAS should be from echocardiographic measurements. MLVOTG should be the maximal gradient recorded.

5. Frequently Asked Questions (FAQ)

Q1: What is considered high risk?
A: Generally, ≥6% 5-year risk is considered high enough to consider ICD implantation, but clinical judgment is essential.

Q2: How accurate is this calculator?
A: The model was validated in large HCM cohorts but should be used in conjunction with clinical assessment.

Q3: What if some parameters are missing?
A: The calculator requires all parameters for accurate risk estimation. Missing data reduces accuracy.

Q4: Does this replace clinical judgment?
A: No, it provides quantitative risk estimation but should be integrated with overall clinical evaluation.

Q5: Can this be used for pediatric patients?
A: The calculator was developed for adults. Use in pediatric patients should be done with caution.