Background: Up to 30–50% of chronic heart failure patients who underwent cardiac resynchronization therapy (CRT) do not respond to the treatment. Therefore, patient stratification for CRT and optimization of CRT device settings remain a challenge.Objective: The main goal of our study is to develop a predictive model of CRT outcome using a combination of clinical data recorded in patients before CRT and simulations of the response to biventricular (BiV) pacing in personalized computational models of the cardiac electrophysiology.Materials and Methods: Retrospective data from 57 patients who underwent CRT device implantation was utilized. Positive response to CRT was defined by a 10% increase in the left ventricular ejection fraction in a year after implantation. For each patient, an anatomical model of the heart and torso was reconstructed from MRI and CT images and tailored to ECG recorded in the participant. The models were used to compute ventricular activation time, ECG duration and electrical dyssynchrony indices during intrinsic rhythm and BiV pacing from the sites of implanted leads. For building a predictive model of CRT response, we used clinical data recorded before CRT device implantation together with model-derived biomarkers of ventricular excitation in the left bundle branch block mode of activation and under BiV stimulation. Several Machine Learning (ML) classifiers and feature selection algorithms were tested on the hybrid dataset, and the quality of predictors was assessed using the area under receiver operating curve (ROC AUC). The classifiers on the hybrid data were compared with ML models built on clinical data only.Results: The best ML classifier utilizing a hybrid set of clinical and model-driven data demonstrated ROC AUC of 0.82, an accuracy of 0.82, sensitivity of 0.85, and specificity of 0.78, improving quality over that of ML predictors built on clinical data from much larger datasets by more than 0.1. Distance from the LV pacing site to the post-infarction zone and ventricular activation characteristics under BiV pacing were shown as the most relevant model-driven features for CRT response classification.Conclusion: Our results suggest that combination of clinical and model-driven data increases the accuracy of classification models for CRT outcomes.

Cardiac resynchronization therapy (CRT) has been shown as an essential treatment of patients with heart failure, leading to improvements in symptoms, left ventricular (LV) function, and survival. However, up to 30% of appropriately selected patients remain nonresponders to CRT. The aim of our study was to test a hypothesis on the impact of lead positioning in the ventricular walls on CRT response in patients with advanced chronic heart failure with and without pre-operative inter and intraventricular myocardial dyssynchrony. We examined 53 guideline-selected CRT candidates. Response to CRT was defined in 6 months after implantation of CRT devices. All patients underwent standard and Doppler echocardiography for assessment of LV function and mechanical dyssynchrony. Individual right ventricular (RV) and LV lead tip position, inter-lead distance, and the horizontal and vertical components were measured on the radiograph images with using an automated custom made software Our results showed that the RLV inter-lead distance is an essential parameter correlated with the CRT outcomes. A logistic model comprising the RLV inter-lead distance with parameters of dyssynchrony demonstrated a high predictive power for odds of CRT success.

Aim. To evaluate the effect of atrial fibrillation (AF) catheter ablation (CA) on long-term freedom from AF and left heart reverse remodeling in patients with heart failure with reduced ejection fraction (HFrEF).Methods. There were 47 patients (mean age 53.3 ± 10 years, 39 males) enrolled into single-center observational study, with left ventricular ejection fraction (LVEF) <40 %. Patients underwent CA for AF refractory to antiarrhythmic drugs. Baseline clinical data and diagnostic tests results were obtained during personal visits and / or via secure telemedical services. Personal contact with evaluation of recurrence of AF and echocardiographic values was performed with 30 (64 %) patients.Results. Paroxysmal AF was present in 12 (40 %) patients, persistent – in 18 (60 %). During mean follow-up of 3 years (0.5–6 years) redo ablation was performed in 9 patients (30 %) with average number of 1.3 procedures per patient. At 6 months 24 (80 %) patients were free from AF, at last follow-up – 16 (53 %). The mean time to first recurrence following CA was 15.6±13.3 months. Follow-up echocardiography revealed significant LVEF improvement (р<0,0001), reduction of left atrium size (р<0,0001), left ventricle end-diastolic volume (р<0,002) and left ventricle endsystolic volume (p<0,0001) and mitral regurgitation (р=0,001).Conclusion. AF CA in patients with HFrEF is associated with improvement in systolic function and left heart reverse remodeling. Durable long-term antiarrhythmic effect often requires repeated procedures.

No abstract

Aim. To determine quantitative criteria for assessing the therapeutic benefits and the most informative time frames after cardiac resynchronization therapy (CRT) to assess its long-term effectiveness (1, 2, 3 years of follow-up) based on retrospective analysis. To assess the CRT effectiveness, parameters of left ventricular (LV) reverse remodeling and signs characterizing the clinical CRT response were considered.Material and methods. This single-center, retrospective, non-randomized study included data from 278 patients with implanted CRT devices. Quantitative criteria for assessing CRT effectiveness were determined using a two-step cluster analysis of patients 1, 2, and 3 years after CRT by LV reverse remodeling parameters.Results. In the dataset with satisfactory division accuracy, after the first year, two clusters were identified, which are conventionally named as “non-responders” and “responders”. Two and three years after therapy, patients were classified into three clusters: “non-responders”, “responders” and “super-responders”. For the obtained clusters, we found cutoff values for LV reverse remodeling parameters, which can be used as criteria for response to therapy.The study identified the most informative time frames for assessing the postoperative CRT effectiveness 1, 2, 3 years after the surgery. At the same time, the clinical response to therapy is manifested earlier in comparison with the reverse LV remodeling.Despite the high divisibility of patients into responders and non-responders, predictive models of CRT effectiveness created using the available data from standard diagnostic protocols for heart failure patients have insufficient accuracy to be used for making decisions on therapy appropriateness. This circumstance indicates the need to receive additional data to improve the forecasting quality.Conclusion. The study revealed a period for assessing the clinical response and changes in LV reverse remodeling after CRT surgery, which is important for the optimal choice of postoperative therapy. It has been shown that in most cases, one year after surgery is sufficient to assess the clinical response, and the process of LV reverse remodeling can last up to two years on average.When assessing the CRT effectiveness by reverse remodeling, along with a change in LV end-systolic volume (ESV), it is necessary to take into account LV end-diastolic volume (EDV) changes. The change in LV ejection fraction showed a significantly lower value among the analyzed parameters in assessing the CRT effectiveness. Based on the cluster classification of patients, a dividing rule was established for responders and non-responders in the first and second years after surgery with an accuracy of 97%: a decrease in LV ESV and EDV by 9% or more compared to preoperative values.