The VISTA Scores: Development and Internal Validation of Novel Clinical Models for Predicting Recurrence and...

Background/Objectives: Scar-related ventricular tachycardia (VT) remains a major contributor to morbidity and mortality in patients with structural heart disease (SHD), despite advances in catheter ablation (CA). Existing risk scores are limited by their focus on procedural outcomes, restricted variable sets, and insufficient integration of arrhythmic burden. This study aimed to bridge this gap in evidence and develop and internally validate two novel, clinically applicable prediction models-the VISTA-R and VISTA-M scores-for estimating the risk of 24-month arrhythmic recurrence and mortality following VT ablation. Methods: We analyzed a retrospective, single-center cohort of consecutive patients undergoing radiofrequency catheter ablation (RFCA) for scar-related VT in the setting of SHD and included a comprehensive set of clinical, arrhythmic, device-related, and procedural variables. Candidate predictors were identified through univariate logistic regression and subsequently incorporated into an exhaustive combinatorial modeling framework, generating over 1000 candidate models per endpoint. Final model selection was based on discrimination, calibration, and clinical interpretability. Internal validation was performed using leave-one-out cross-validation. Results: The VISTA-M model, incorporating left ventricular ejection fraction (LVEF), NYHA class IV at admission, number of clinical VT morphologies, and appropriate implantable-cardioverter defibrillator (ICD) shocks, demonstrated strong discriminative performance (AUC 0.866 in-sample, 0.826 cross-validated) and a pseudo R² of approximately 30%. The VISTA-R model, including history of electrical storm (ES), ICD shocks, and VT morphologies, showed moderate discrimination (AUC 0.70 in-sample, 0.63 cross-validated) with a pseudo R² of approximately 12%. Both models enabled meaningful risk stratification with progressively increasing event rates across the predefined risk classes. Conclusions: In conclusion, the VISTA scores provide parsimonious and clinically applicable tools for a comprehensive risk stratification after VT RFCA. Mortality is primarily driven by myocardial dysfunction and heart failure severity, whereas recurrence reflects arrhythmic burden and electrical instability. External validation is warranted to confirm these findings.