Associations of the left ventricle myocardial deformation parametrs with cardiovascular risk in patients with an implanted cardioverter-defibrillator

Abstract

Aim. To study the impact of left ventricle (LV) deformation parameters by the two-dimensional strain method to assess the intended use of cardioverter defibrillator implantation for primary prevention of sudden cardiac death.Methods. The study included 133 patients with congestive heart failure NYHA 3-4 functional class with a LV ejection fraction ≤35%, taking optimal drug therapy. The speckle-tracking echocardiography with the estimation of LV deformation indicators (segmental strains, global longitudinal and circular strain [GLS and GCS, respectively]) was carried out, after which the implantation of defibrillator for the purpose of primary prevention of sudden death was performed. The patients enrolled in the study were observed prospectively for two years after the operation (visits to the clinic after 3, 6, 12, 18, 24 months) for the registration of first-time ventricular tachyarrhythmias (VT) paroxysms and assessment of one-year cardiovascular mortality.Results. The arrhythmic endpoint appeared in 27 patients (20%), 19 patients (14%) died due to acute decompensation of heart failure. Comparative analysis of the studied parameters of LV deformation did not reveal statistically significant differences in the groups of survivors and deceased patients. Patients with VT had the worst deformation characteristics. It was found that at absolute values of GLS<6% the risk of the first VT manifestation during the observation period increased almost threefold (odds ratio (OR)=2.59; 95% confidence interval (CI): 1.07-6.26; p=0.031). The second independent predictor of the arrhythmic point was the longitudinal strain of the anterior wall (OR=1.28; 95%CI: 1.14-1.45; p=0.0001 for univariate analysis and OR=1.55; 95%CI: 1.18-2.04; p=0.002 for multivariate analysis). Based on the multifactor analysis, which included indicators of myocardial deformation, age, sex, and ischemic heart disease, predictive model was obtained to predict VT with 71% sensitivity and 97% specificity. The area under the curve was 0.916 (95%CI: 0.850-0.981; p=0.0001).Conclusion. LV deformation parameters do not help to predict cardiovascular mortality, but may be useful in stratification of VT risk. To achieve this GLS value as well as the segmental map of regional strains can be used.