ECG changes and their prognostic value for the development of sudden cardiac death in HCM patients

Abstract

Background. Hypertrophic cardiomyopathy (HCM) is a primary myocardial disease characterized by an increase in the left ventricular (LV) wall thickness, which is not explained only by abnormal loading conditions. The development of sudden cardiac death (SCD) is one of the most dangerous complications of HCM. The aim of our study was to evaluate the prognostic value of electrocardiography (ECG) changes for the development of SCD in the Ukrainian population of patients with HCM. Materials and methods. We evaluated 350 patients with HCM who were examined in the City Clinical Hospital 8 (Kharkiv, Ukraine) from 2006 to 2021. The diagnosis of HCM was made in accordance with the current guidelines of the European Society of Cardiology. Clinical and instrumental data of patients with HCM were analyzed retrospectively, including general clinical data, 12-lead ECG, echocardiography, Holter monitoring, calculation of the 5-year risk of SCD according to the HCM Risk-SCD tool. The endpoint of the study was SCD and its surrogates, including adequate performance of the implantable cardioverter-defibrillator and the state after a successful resuscitation. Results. Follow-up was 5.0 (1.5–9.5) years. During this time, 16 patients (4.6 %) reached the endpoint, which was 0.9 %/year. According to the HCM Risk-SCD, 5 (31.3 %) patients in this group were at a high (≥ 6 %) and 3 (18.8 %) were at an intermediate risk of SCD (≥ 4 and < 6 %). A multivariable Cox regression analysis has shown that independent predictors of SCD are syncope (hazard ratio (HR) 3.81, 95% confidence interval (CI) 1.11–13.12, p = 0.034), systolic blood pressure (HR 0.97, 95% CI 0.94–0.99, p = 0.026), ECG with “infarction-like” ST elevation (HR 6.81, 95% CI 2.09–22.16, p = 0.001) and PQ interval value (HR 1.03, 95% CI 1.01–1.05, p = 0.002), Harrell’s C-index (HR 0.84, 95% CI 0.73–0.95, p < 0.0001). Conclusions. The proposed HCM Risk-SCD tool was not effective enough in predicting SCD in our study. In order to improve the risk stratification, ECG changes (“infarction-like” ST elevation and PQ interval prolongation) and systolic blood pressure lowering can be used, which were found to be independent predictors of SCD risk.