Validation of the new American College of Cardiology/American Heart Association Guidelines for the risk stratification of sudden cardiac death in a large Mediterranean cohort with Hypertrophic Cardiomyopathy

Background: The aim of our study was to assess the performance of the new American College of Cardiology (ACC)/American Heart Association (AHA) Guidelines, with respect to sudden cardiac death (SCD) prevention, in comparison with the established risk score of the European Society of Cardiology (hypertrophic cardiomyopathy [HCM] Risk-SCD), in a large Mediterranean cohort of HCM patients. Methods: The clinical and imaging characteristics of 784 HCM patients (mean age at first evaluation 52 +/- 16 years, 67.2% males) were analyzed retrospectively. The sensitivity, specificity, and negative predictive value for SCD events of the presence of >1 risk factor for SCD according to the ACC/AHA Guidelines 2020 and of the HCM Risk-SCD>6% and HCM Risk-SCD>4% were estimated during follow-up. Results: During follow-up, 47 (6%) patients suffered an SCD event. The presence of >1 major risk factor for SCD according to the new ACC/AHA Guidelines had 96% sensitivity (95% CI 85.5-99.5%) with modest specificity of 59% (95% CI 55-62.2%) and negative predictive value of 99.5% (95% CI 98.2-99.9%). On the contrary, HCM-Risk-SCD>6% had a relatively low sensitivity (32%, 95% CI 19.1-47.1%) and high specificity of 95% (95% CI 93.1-96.4%), whereas, HCM-Risk-SCD>4% had sensitivity of 60% (95% CI 44-74%) and specificity of 83.9% (95% CI 80-85.6%). Both the HCM Risk-SCD cut-off values demonstrated lower negative predictive value but higher accuracy than the ACC/AHA algorithm for SCD prediction. Conclusion: The novel ACC/AHA proposed algorithm identifies most of the patients with an SCD event with the cost of numerous defibrillator implantations. HCM-Risk-SCD demonstrated higher specificity, whereas its sensitivity and negative predictive value are modest. (c) 2021 Hellenic Society of Cardiology. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).