SPECT-based Prediction and Evaluation of CRT Efficacy in CHF

In heart failure, abnormal activation of cardiac sympathetic system has been shown to be of pathophysiological significance. However, the left ventricular (LV) dyssynchrony has a detrimental effect on LV systolic and diastolic functions in heart failure patients. The effects of LV dyssynchrony on cardiac sympathetic activity are not yet fully understood. Dilated cardiomyopathy is a common cause of severe chronic heart failure. Cardiac resynchronization therapy (CRT) is a disease modifying device-driven treatment that can reduce morbidity and mortality in patients with heart failure. However, this type of treatment does not lead to the expected results in 25% to 30% of patients despite the successful implantation of a CRT device. In addition, CRT is associated with high cost and potential morbidity. Therefore, the search for new highly informative criteria for selecting patients for this type of treatment remains a relevant task of modern medicine. It is expected that the results obtained will complement and expand current state of knowledge regarding the relationships between cardiac remodeling processes and the state of cardiac sympathetic activity. In addition, obtained data will allow to predict LV remodeling dynamics after the correction of contractile dysfunction of the heart.

Inclusion criteria

• Chronic heart failure NYHA III and IV class
• LVEF ≤ 35 %
• QRS ≥ 150 ms on ECG
• The presence of LBBB on ECG
• Sinus rhythm
• Optimal pharmacological treatment of heart failure

Exclusion criteria

• Contraindications to SPECT due to hypersensitivity to radiopharmacuticals such as 2-methoxy-isobutyl-isonitrile-(99mTc) and (123)I-Meta-iodobenzylguanidine or any of the excipients
• Pregnancy
• Breastfeeding
• Refusal to participate