Parameters used in the control of ventricular rate in patients with permanent atrial fibrillation

Purpose . To analyze the possibility of using high-sensitivity cardiac troponin I (hsTnI), N-terminal pro-B type natriuretic peptide (NT-proBNP), tissue hemodynamics parameters, echocardiographic data and the quality of life for selection of the individual regimen for ventricular rate (VR) control drug therapy in patients with permanent atrial fibrillation (AF). Methods. The study included 120 patients aged >60 years old with the diagnosis of permanent AF, who gave the informed consent. Patients were randomized into 2 groups according to the target range of VR at rest: 60-79 bpm (first group, n=60) and 80-100 bpm (second group, n=60). Patients in both groups were prescribed a selective beta1 -adrenoceptors blocker bisoprolol for VR control. The following parameters were determined before randomization and after 6 months of VR control in the target ranges: atrial and ventricular remodeling with transthoracic echocardiography; biochemical markers hsTnI and NT-proBNP; the tissue hemodynamics by the mean flow velocity (Vm) and the value of the pulsatility index (PI) using high-frequency ultrasound Doppler flowmetry; the patients’ quality of life with the “Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) Questionnaire” and the “EQ-5D-5L” system with a scale EQ-VAS. Results . VR at rest after 6 months was 70±3 and 88±4 bpm (p 1 , p 2 ˂0.001) in the first and second groups, respectively (p 1 - comparing the initial and achieved values, p 2 - values of the first and second groups). The level of hsTnI significantly decreased in both groups, but it was more pronounced in the 60-79 bpm range group (p˂0.001). Spearman’s correlation coefficients between the degree of decrease in VR and decrease in the level of hsTnI were 0.45 (p˂0.001) and 0.44 (p˂0.001) in the first and second groups, respectively. AFEQT and EQ VAS scores of quality of life improved after 6 months in both groups: the increase in the total AFEQT score in the first group -56.2±17.0% (M±SD), in the second - 42.6±15.3% (p˂0.001); EQ VAS values also increased, but differences between groups were not significant (p=0.078). In both the first and second groups, a strong positive correlation was found between the degree of decrease in VR and increase in the total score of the AFEQT questionnaire. The tendency toward an increase in Vm and a decrease in PI observed in both groups was more pronounced in the group with VR of 80-100 bpm, where Vm increased by more than 10% (p 1 , p 2 ˂0.001). Changes in NT-proBNP under the influence of therapy for the reported observation period did not reach statistical significance in both groups (p 1 =0.092, p 2 =0.063). There was no significant dynamics of echocardiographic parameters of myocardial remodeling. Conclusion . The degree of chronic myocardial damage caused by arrhythmia (estimated by hsTnI), as well as the tissue hemodynamic parameters Vm and PI, can be the basis for individualized selection of the target VR range. This approach will allow to find a balance between cardioprotection and improvement of tissue blood flow. In creating the algorithm of selecting the target VR for patients older than 60 years with permanent AF, it is advisable to use such parameter as the degree of the initial VR change and quality of life data from the “AFEQT Questionnaire”.