Head-to-head comparison of ESC 2023 and 2024 ACC/AHA primary-prevention ICD selection strategies in hypertrophic cardiomyopathy: insights from a real-world ICD-implanted cohort
A Diaz Exposito, F Costa, J Munhiz Saenz-Diez, G Berteli Garcia, A Ruiz Salas, N Ouedraogo, A Robles Mezcua, P Marquez Camas, C Jimenez Rubio, A Perez Cabeza, A Barrera Cordero, M Jimenez Navarro, J M Garcia PinillaAbstract
Background
Primary-prevention ICD decision-making in hypertrophic cardiomyopathy (HCM) remains challenging. ESC 2023 integrates the 2014 HCM Risk-SCD model with phenotypic modifiers, whereas ACC/AHA 2024 is predominantly risk-marker–driven.
Purpose
To compare how ESC 2023 and ACC/AHA 2024 frameworks classify ICD candidates and capture arrhythmic events.
Methods
Consecutive HCM patients undergoing primary-prevention ICD implantation at a tertiary centre (2015–2024) were retrospectively included. The primary endpoint was appropriate ICD therapy for sustained ventricular tachyarrhythmias (ATP and/or shock), adjudicated at annual in-person visits plus remote monitoring. Guideline classes were applied retrospectively.
Results
The cohort included 142 patients (age 55.4±13.9 years) with mean follow-up 4.51±2.63 years. Appropriate ICD therapy occurred in 22/142 (15.5%). Mean time to first appropriate therapy was 2.9±2.0 years. ESC 2023 classified 38 (26.8%) as Class IIa, 85 (59.9%) as IIb, and 19 (13.4%) as III, whereas ACC/AHA 2024 classified 95 (66.9%) as IIa, 27 (19.0%) as IIb, and 20 (14.1%) as III; class-level agreement was low (κ=0.05). ESC Class IIa identified a more event-enriched, higher-risk subgroup than ACC/AHA Class IIa (appropriate therapy in 10/38, 26.3% vs 17/95, 17.9%). When Class IIa was used as the action threshold (IIa vs IIb/III), ACC/AHA 2024 was more sensitive (77.3% vs 45.5%) but less specific (35.0% vs 76.7%) than ESC 2023. Conversely, using an eligibility definition (eligible = IIa/IIb vs III), ESC 2023 achieved complete event capture (22/22; NPV 100%), whereas ACC/AHA 2024 missed one event (21/22; NPV 95%).
Conclusions
ESC 2023 and ACC/AHA 2024 are not interchangeable in primary-prevention ICD decision-making for HCM. ACC/AHA 2024 prioritises sensitivity at a Class IIa threshold, whereas ESC 2023 better supports an eligibility-based safety-first approach in this ICD-implanted cohort (IIa+IIb).