hcm_risk_scd: HCM Risk-SCD Calculator

In cliot: Clinical Indices and Outcomes Tools

HCM Risk-SCD Calculator

Description

Calculates the 5-year risk of Sudden Cardiac Death (SCD) in patients with Hypertrophic Cardiomyopathy (HCM). The score is used to guide decisions regarding Implantable Cardioverter Defibrillator (ICD) placement. It predicts risk based on age, maximal wall thickness, left atrial size, max LVOT gradient, family history of SCD, non-sustained VT, and unexplained syncope.

Usage

hcm_risk_scd(age, max_wall_thickness_mm, la_diameter_mm, max_lvot_gradient_mmhg,
             family_history_scd, nsvt, unexplained_syncope)

Arguments

age	Numeric. Patient age in years (Validated for 16-115).
max_wall_thickness_mm	Numeric. Maximal Left Ventricular wall thickness in mm. (Note: The algorithm caps the risk impact at 35mm).
la_diameter_mm	Numeric. Left Atrial diameter in mm (M-mode/2D PLAX).
max_lvot_gradient_mmhg	Numeric. Maximal Left Ventricular Outflow Tract gradient in mmHg (at rest or with Valsalva provocation).
family_history_scd	Numeric (0 or 1). History of Sudden Cardiac Death in >= 1 first-degree relative < 40 years old or with confirmed HCM. (1 = Yes).
nsvt	Numeric (0 or 1). Non-sustained Ventricular Tachycardia (>= 3 consecutive ventricular beats at >= 120 bpm, < 30s duration) on monitoring. (1 = Yes).
unexplained_syncope	Numeric (0 or 1). History of unexplained syncope (unrelated to neurocardiogenic causes). (1 = Yes).

Value

A list containing:

Risk_SCD_5_Year	The estimated percentage risk of sudden cardiac death over 5 years.
Risk_Category	Classification (Low <4%, Intermediate 4-6%, High >=6%).
Recommendation	Clinical guidance regarding ICD implantation according to ESC guidelines.

References

O'Mahony C, Jichi F, Pavlou M, et al. A novel clinical risk prediction model for sudden cardiac death in hypertrophic cardiomyopathy (HCM Risk-SCD). Eur Heart J. 2014;35(30):2010-2020. doi:10.1093/eurheartj/eht439

Examples

# Example 1: High Risk
# 45yo, 25mm wall, 45mm LA, 80 mmHg grad, NSVT present
hcm_risk_scd(45, 25, 45, 80, 0, 1, 0)

# Example 2: Low Risk
# 60yo, 18mm wall, 40mm LA, 10 mmHg grad, No other risks
hcm_risk_scd(60, 18, 40, 10, 0, 0, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.