Improving Risk Stratification in Hypertrophic Cardiomyopathy: A Novel Score Combining Echocardiography, Clinical, and Medication Data
Organizations: Department of Electronics, Information and Bioengineering (DEIB), Politecnico di Milano, 20133 Milano, Italy · CardioTech Lab, IRCCS Centro Cardiologico Monzino, 20138 Milano, Italy · Cardiomyopathy Unit, Careggi University Hospital, 50134 Florence, Italy · Univ Rennes, CHU Rennes, Inserm, LTSI – UMR 1099, 35000 Rennes, France ·
Abstract
Hypertrophic cardiomyopathy (HCM) requires accurate risk stratification to inform decisions regarding ICD therapy and follow-up management. Current established models, such as the European Society of Cardiology (ESC) score, exhibit moderate discriminative performance. This study develops a robust, explainable machine learning (ML) risk score leveraging routinely collected echocardiographic, clinical, and medication data, typically contained within Electronic Health Records (EHRs), to predict a 5-year composite cardiovascular outcome in HCM patients. The model was trained and internally validated using a large cohort (N=1,201) from the SHARE registry (Florence Hospital) and externally validated on an independent cohort (N=382) from Rennes Hospital. The final Random Forest ensemble model achieved a high internal Area Under the Curve (AUC) of 0.85 +- 0.02, significantly outperforming the ESC score (0.56 +- 0.03). Critically, survival curve analysis on the external validation set showed superior risk separation for the ML score (Log-rank p = 8.62 x 10^(-4) compared to the ESC score (p = 0.0559). Furthermore, longitudinal analyses demonstrate that the proposed risk score remains stable over time in event-free patients. The model high interpretability and its capacity for longitudinal risk monitoring represent promising tools for the personalized clinical management of HCM.
Figures & tables
| Study | Measures | Output | Clinical flaws |
|---|---|---|---|
| [ 8 ] | ECG-derived electrical phenotypes | ECG pattern subgroups in HCM (unsupervised phenotyping) | No direct risk stratification output; no time-to-event modeling; no longitudinal assessment of ECG evolution |
| [ 4 ] | ECG-derived arrhythmic risk markers | Associations between ECG repolarization markers and myocardial disarray/fibrosis | Mechanistic insight rather than patient-level risk; no risk stratification; No ICD decision support |
| [ 15 ] | Conventional echocardiography measurements; basic clinical variables | Predicted probability or class of composite adverse cardiac events | Static baseline risk estimation; no longitudinal risk evolution; limited generalizability |
| [ 9 ] | LGE extent and location; CMR feature-tracking strain; clinical and echocardiographic variables | Static risk score for long-term major adverse cardiovascular events; stratification into low/medium/high risk groups | Dependence on CMR imaging; static risk estimation without temporal updating |
| [ 10 ] | Myocardial fibrosis and scar patterns from LGE-CMR images; CMR-derived structural measures; Echo-derived features | Static probability of arrhythmic sudden cardiac death | Computationally intensive; reliance on advanced CMR imaging; static risk estimation |
| Model | Sensitivity | Specificity | Balanced Accuracy | F1-Score | AUC |
|---|---|---|---|---|---|
| RF | |||||
| GB | |||||
| LR | |||||
| SVM | |||||
| Ensemble RF | 0.351 | 0.877 | 0.614 | 0.342 | 0.723 |
Clinical Outcome Prediction
Clinical outcome prediction uses patient records, imaging, signals, and biomarkers to estimate risks, disease trajectories, treatment response, and survival.
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