RESUMO
Background: Sudden cardiac death (SCD) represents the most severe complication of hypertrophic cardiomyopathy (HCM). The risk stratification of SCD in patients with HCM remains a subject of ongoing debate, and the utility of left atrial (LA) and left ventricular (LV) myocardial strain for risk stratification of also SCD remains uncertain. Through use of feature-tracking cardiac magnetic resonance (FT-CMR), this study aimed to investigate the attenuation of LA and LV strain in HCM and to assess their predictive value in SCD. Methods: This retrospective and cross-sectional study included patients with HCM who underwent 3.0 T cardiac magnetic resonance (CMR) at a single institution. Feature-tracking strain analysis was conducted to obtain the strain rate (SR) and LV strain and to evaluate LV function. LA strain was measured during different functional phases including left atrial reservoir strain (LARS), LA conduit strain (LACS), and LA booster strain. All patients were categorized into high- and low-risk groups for SCD as defined by the 2020 American Heart Association/American College HCM implantable cardioverter defibrillator class of recommendation algorithm. Comparison between the two groups was conducted using the independent samples t test and the nonparametric rank sum test. Multivariate logistic regression analysis was performed to further identify the factors influencing SCD risk in HCM. Results: Compared with those in the low-risk group, patients in the high-risk group had lower left ventricular ejection fraction (LVEF), LV stroke volume index (LVSVI), and LA stroke volume index (LASVI) but a higher LV end-systolic volume index (LVESVI), LV maximum wall thickness, and late gadolinium enhancement (LGE) (P<0.001). LV strain, SR, and LA strain all showed significant differences between the high- and low-risk groups (LARS: P=0.04; LACS: P=0.02; all other P values <0.001). The LV global circumferential strain (LVGCS) had a strong negative correlation with LVEF in patients with HCM (r=-0.76; P<0.001). Multivariate analysis showed that LV global radial strain (LVGRS) and LARS could be used for categorizing the patients into the high-risk group [LVGRS: odds ratio (OR) =0.69; 95% confidence interval (CI): 0.55-0.87, P<0.001; LARS: OR =1.39; 95% CI: 1.02-1.90, P=0.03]. The combined LVGRS-LARS model exhibited a superior diagnostic value for high risk of SCD [area under the curve (AUC) =0.95; 95% CI: 0.90-1.00; P<0.001] compared to LARS alone (AUC =0.63; 95% CI: 0.51-0.76; P=0.04). Conclusions: LA and LV strain measured by FT-CMR can accurately identify those patients with HCM at a high risk of SCD. This approach may prove considerably value in guiding early therapeutic intervention with implantable cardioverter-defibrillators (ICDs) to prevent adverse clinical outcomes.
RESUMO
Sudden cardiac death (SCD) represents the most severe complication of hypertrophic cardiomyopathy (HCM). However, the relation between strain, strain rate (SR), and risk factors in SCD risk stratification remains elusive. The study aimed to assess the attenuation of strain and SR in HCM by feature tracking cardiac magnetic resonance. All strain and SRs were obtained automatically by feature tracking, with manual adjustment of endocardial and epicardial borders. Strain indicators included left ventricular global longitudinal, circumferential, global radial strain (GRS), peak diastolic-longitudinal, circumferential, and radial SR. Patients were categorized into high-risk and low-risk groups for SCD based on the 2020 American Heart Association/American College HCM risk-SCD model. The correlation between strain/SR and SCD risk factors was assessed through Spearman correlation analysis. Furthermore, a multivariate logistic regression analysis was conducted to explore the factors that influence SCD risk in HCM patients. A total of 105 HCM patients were analyzed in this study, including 38 patients in the high-risk group, and 67 patients in the low-risk group. Compared with the low-risk group, the high-risk group exhibited significantly worse strain and SR (p <0.001). Furthermore, both circumferential and GRS and SR exhibited meaningful associations with risk factors for SCD. Additionally, GRS emerged as an independent risk factor for predicting heightened SCD risk in HCM patients (p <0.001). In conclusion, left ventricular strain and SR based on feature tracking-cardiac magnetic resonance can be evaluated for SCD risk and are strongly associated with SCD risk factors.
