Factors Associated with a Positive Hemodynamic Response to Cardiac Resynchronization Therapy

AIM: This study aimed to conduct a comparative analysis of clinical, electrocardiographic, and echocardiographic factors in patients with chronic heart failure (CHF) with different hemodynamic responses to cardiac resynchronization (CRT) to assess the possibility of their use in predicting the positive effect of CRT. 
MATERIALS AND METHODS: The study included 136 patients with New York Heart Association grade 34 CHF with a left ventricular ejection fraction of 35%, QRS duration of 150 ms, QRS duration of 130149 ms, and QRS morphology of left bundle branch block (LBBB). For CHF treatment and primary prevention of sudden cardiac death, a cardioverter-defibrillator with CRT (CRT-D) function was implanted. The enrolled patients were followed up prospectively for 1 year to record the endpoint, namely, hemodynamic response to CRT, assessed by a decrease in the end-systolic volume of the left ventricle by 15%. 
RESULTS: During the 1-year follow-up, the primary endpoint was registered in 62 (46%) patients. With a one-way logistic regression, four indicators with the highest predictive potential (p 0.05) and associated with the occurrence of the studied endpoint were identified. Based on the results of the multivariate regression analysis, a prognostic model was developed, which included three factors with the highest levels of statistical significance, namely, a history of indications of a previous correction of valvular insufficiency, QRS duration, and LBBB criteria according to Strauss. The diagnostic efficiency of the model was 73% (sensitivity, 80%; specificity, 68%). The electrocardiographic parameters of the Strauss LBBB criteria and QRS duration were independent predictors of the studied endpoint. 
CONCLUSIONS: The developed multivariate prognostic model may be useful in the selection of patients with CHF reduced ejection fraction for implantation of devices with CRT function; the lack of external validation limits its application in practice.