Individualized maximal wall thickness adjustments did not improve prediction of sudden cardiac death or ICD therapies in hypertrophic cardiomyopathy patients.
Do individualized maximal wall thickness adjustments improve the prediction of arrhythmic events in patients with hypertrophic cardiomyopathy compared to raw maximal wall thickness measurements?
Adjusting maximal wall thickness for age, sex, and body surface area does not improve the prediction of sudden cardiac death or arrhythmic events in patients with hypertrophic cardiomyopathy compared to raw measurements.
Absolute Event Rate: 0% vs 0%
Abstract Background A recent study from the UK Biobank proposed individualized maximal wall thickness (MWT) thresholds (adjusted for age, sex, and body surface area) to replace the classic 15mm criterion and improve diagnostic accuracy in patients with suspected hypertrophic cardiomyopathy (HCM). Our study aimed to assess whether this novel approach can also strengthen the association between MWT and arrhythmic events in patients with established HCM. Methods We conducted a multicenter international retrospective analysis of HCM patients who underwent cardiac magnetic resonance (CMR) for diagnostic confirmation and risk stratification. MWT was measured using both echocardiography and CMR. For each patient, the individualized upper limit of normal (ULN) for MWT was calculated and compared with the measured MWT using two different metrics: absolute excess hypertrophy (measured – ULN) and relative excess hypertrophy (measured / ULN). The primary composite endpoint included sudden cardiac death (SCD), appropriate implantable cardioverter-defibrillator (ICD) discharges, and sustained ventricular tachycardia (VT). The secondary endpoint was the presence of non-sustained VT (NSVT) on Holter monitoring. Results A total of 530 HCM patients (mean age 49 ± 17 years; 44% male) were included. Mean MWT was 20 ± 5 mm on transthoracic echocardiography and 21 ± 5 mm on CMR, with a theoretical individualized ULN of 13 mm (IQR 12–14 mm). Clinical risk factors included a family history of SCD (13%), unexplained syncope (12%), and NSVT (19%). Over a median follow-up of 50 months, 28 patients experienced a primary endpoint event (15 SCDs, 6 ICD discharges, and 7 sustained VTs). No significant differences in MWT were observed between patients with and without primary endpoint events. Similarly, neither absolute nor relative excess hypertrophy improved predictive value for SCD-related outcomes. For NSVT, significant differences in MWT, absolute, and relative excess hypertrophy were noted. However, hypertrophy indexing methods showed no advantage over raw MWT measurements in prognostic performance (Wald 9 vs. 13, respectively). Conclusions In this cohort, novel adjustments to MWT values, including indexing to body surface area and the use of predicted MWT thresholds, did not improve the prediction of SCD-related events or appropriate device therapies. These findings suggest limited utility for these methods in HCM risk stratification.
Amador et al. (Sat,) reported a other. Individualized maximal wall thickness adjustments did not improve prediction of sudden cardiac death or ICD therapies in hypertrophic cardiomyopathy patients.