Predictors of sudden cardiac death and ventricular tachyarrhythmias in patients with hypertrophic cardiomyopathy

Abstract

Abstract Background Determining additional predictors that allow more accurate identification of patients who need primary prevention of sudden cardiac death (SCD) and ventricular tachyarrhythmias (VT) in patients with hypertrophic cardiomyopathy (HCM) is one of the most important tasks. High-risk patients can be more accurately identified using modern non-invasive research methods. Purpose Identification of new risk predictors for SCD and ventricular tachyarrhythmias based on cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and T1-mapping in patients with hypertrophic cardiomyopathy. Materials and methods Clinical data of 98 HCM subjects (58 males and 40 females, median age 46.5 [35.2; 54.7] treated in our centre in the period between 2013 and 2017 have been studied. All patients underwent CMR with LGE and T1-mapping. Results According to the existing ESC-2014 scale, 45 (46%) of the 98 patients included in the study had a low risk, an intermediate risk was identified in 26 (26%) patients and a high risk of SCD in 27 (28%). During the follow-up period 16 episodes of sudden cardiac death were recorded. Of these, only 8 (50%) patients had a high risk on the ESC-2014 scale. High-risk patients show significantly greater myocardial fibrosis (Me 28.5%; [21.9; 44.1]) compared with patients with intermediate (Me 17.6% [8.0; 22.5]) and low risk of SCD (Me 11.7%; [5.8; 17.6]), p<0.001. A threshold level of fibrosis volume associated with an adverse outcome was determined, which was 15% (based on determining the maximum rank of statistics). For patients with 15% fibrosis volume, the cumulative survival rate on the Kaplan-Mayer curve over the observation period was 96% (95% CI 88.6–100), while for patients with fibrosis volume ≥15% - 72.4% (95% CI 60.6–86.4). The study showed that in 15 (93.7%) patients out of 16 who had an adverse outcome, the volume of myocardial fibrosis was ≥15%. Episodes of nonsustained ventricular tachycardia were detected in 48 patients (48.7%) according to daily ECG monitoring. To identify patients with ventricular tachyarrhythmias by ROC analysis, the threshold value of extracellular myocardial volume was determined using CMR with LGE and T1 mapping, which was 32.5% (sensitivity 74% and specificity 86%). According to multivariate analysis, one of the independent predictors of ventricular tachyarrhythmias was the level of extracellular myocardial volume ≥32.5% (HR 1.2; 95% CI 1.03–1.4). Conclusion Predictors detected by CMR with LGE and T1 mapping can identify patients with HCM with a high risk of sudden cardiac death and ventricular tachyarrhythmias. Funding Acknowledgement Type of funding source: None