Validation of the hypertrophic cardiomyopathy risk-sudden cardiac death calculator in Asians

Abstract

ObjectiveThe hypertrophic cardiomyopathy (HCM) risk-sudden cardiac death (SCD) calculator endorsed by the 2014 European Society of Cardiology has not been independently validated in the Asians. We aimed to investigate whether the HCM Risk-SCD calculator effectively predicts SCD in Korean HCM population.MethodsAn observational, longitudinal cohort study was performed in 730 patients with HCM from 2007 to 2017. The primary endpoint was a composite of SCD and appropriate implantable cardioverter-defibrillator (ICD) therapy.ResultsDuring a follow-up period of 4288 person-years, 16 (2.2%) patients reached the primary endpoint. This validation study revealed a calibration slope of 0.892 and C-statistics of 0.718. The primary endpoint occurred in 1.1% (7/615), 4.6% (3/65) and 12.0% (6/50) of low-risk, intermediate-risk and high-risk groups, respectively. Although most patients (85.2%) without the primary endpoint were classified into the low-risk group, 7 of 11 SCD (63.6%) occurred in the low-risk group. In univariable and multivariable analysis, sex (woman) was significantly associated with the primary endpoint and emerged as independent predictor. The addition of sex to the HCM Risk-SCD calculator significantly improved the predictive value of the primary endpoint (net reclassification improvement 0.557, p=0.015).ConclusionsIn the Korean HCM population, the HCM Risk-SCD calculator had a high negative predictive value and accuracy for predicting SCD or appropriate ICD therapy, but misclassified a few patients experiencing the primary endpoint as low-risk or intermediate-risk groups.

Evolution of risk stratification and sudden death prevention in hypertrophic cardiomyopathy: Twenty years with the implantable cardioverter-defibrillator

“…Using this strategy in children and adolescents, appropriate device interventions occurred at 3.5%-5% per year, 11,14,66 similar to adults, and with very high sensitivity (no SDs in one study) (Figure 3). 66 Furthermore, the individual risk marker strategy is generalizable across several referral populations with diverse racial and geographic distributions including China 88 and Korea, 89 and in a meta-analysis with 12 other countries including the United Kingdom, Japan, Israel, Scandinavia, and Argentina. 90 Notably, effective prevention of SD with the ICD has been a major determinant of .10-fold reduced overall HCMrelated mortality, from 6% per year in the pre-ICD era to 0.5% per year currently, providing a survival exceeding that of other cardiac and noncardiac diseases that constitute the general risks of living.…”

Increasing evidence that risk scores underperform in predicting sudden death in hypertrophic cardiomyopathy

“…In conclusion, identifying patients at the highest risk for sudden death deserving lifesaving ICD therapy remains a critical management priority in this disease. In this regard, these data from Choi et al ,4 extend our experience with risk stratification by underscoring the principle that the new ESC risk score underperforms in identifying at-risk patients with HCM, throughout the broad disease spectrum. It is our view, now substantiated by considerable data, that the highly sensitive ACC/AHA major risk factor method of using ≥1 of the established individual risk factors considered major within the clinical profile of the patient with HCM, and associated with a greater measure of shared decision-making and opportunity for physician judgement, remains the preferred strategy for risk stratifying individual patients with HCM for primary prevention device therapy.…”

“…Of note, the ESC risk score excludes children and adolescent patients with HCM, a subgroup traditionally considered at particularly high risk for SCD. Prior investigations of this risk score have included only a small number of Asian patients with HCM2 3 and therefore the primary aim of the present Heart study by Choi et al ,4 was to determine the efficacy of the HCM Risk-SCD calculator in a cohort of Korean patients with HCM.…”

“…Over the follow-up, 11 patients died suddenly and six experienced appropriate ICD shocks for ventricular tachyarrythmias, including seven patients with low ESC risk score, three with intermediate scores and six with high-risk scores. Of particular importance was the observation that of the 11 patients who died suddenly due to HCM, the majority (n=7; 64%) had low ESC risk scores that clearly excluded an ICD recommendation 4. Choi et al 4 appropriately conclude that the ESC risk calculator underperforms in detecting Asian patients with HCM who are at increased risk for sudden death events and based on low risk scores would not be protected from sudden death by ICD therapy.…”

Heartbeat: is the keyword ‘atrial’ or ‘fibrillation’?

“…Other interesting articles in this issue of Heart include a study showing that the European Society of Cardiology (ESC) calculator for risk of sudden cardiac death in patients with hypertrophy cardiomyopathy (HCM) had a high negative predictive value and high accuracy in a cohort of 4288 Korean patients, although 1.1% of patients classified as low risk did have appropriate defibrillator therapy or sudden death 6. Maron and colleagues7 discuss the differences between the ESC and American College of Cardiology/American Heart Association (ACC/AHA) strategies for risk prediction in HCM patients and express the opinion that ‘the highly sensitive ACC/AHA major risk factor method of using ≥1 of the established individual risk factors considered major within the clinical profile of the patient with HCM, and associated with a greater measure of shared decision-making and opportunity for physician judgement, remains the preferred strategy for risk stratifying individual patients with HCM for primary prevention device therapy’.…”