CORRELATION OF THE ACHIEVED VENTRICULAR CONTRACTION RATE CONTROL LEVEL WITH LIFE QUALITY IN ELDERLY PATIENTS WITH PERMANENT ATRIAL FIBRILLATION

Aim. To determine the correlation between the degrees of ventricular rate (VR) change achieved as a result of drug therapy and life quality in elderly patients with permanent atrial fibrillation (AF).

Materials and methods. The study included 54 patients aged 82.3±7.1 (M±SD) diagnosed with permanent AF and a selected strategy of long-term VR control. The symptoms in all patients enrolled in the study required adjustment of VR control. Patients’ life quality was assessed based on the questionnaire "Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) Questionnaire" and "EQ-5D-5L" system with a visual analogue scale (EQ-VAS): before selecting the drug therapy for VR control and after its administering. The study included patients who underwent beta-blocker VR-reducing therapy. According to VR value, patients were split into 2 subgroups: with the baseline VR value > 90 beats per 1 minute (beats/min) and a reversible bradycardia (< 60 beats/min) caused by an inadequate dose or an improper combination of control drugs in whom the "adequate control range" (60-100 beats/min at rest) approved by 2016 ESC recommendations was successfully achieved by beta-blocker dosage adjustment. The dynamics of patients’ VR values was observed by electrocardiography at rest – the degree of VR changes against the therapy background was expressed in percentage of the original value. The correlation analysis was made between the degree of VR changes resulting from drug treatment and the degree of life quality indicators improvement in patients (increase in scores of the AFEQT questionnaire and EQ VAS, expressed as a percentage of baseline values).

Results. The most expressed direct correlation was observed between the degree of VR reduction achieved as treatment effect in patients with baseline VR > 90 beats/min with percentage increase of the total score of AFEQT questionnaire. Of all subject subgroups of this questionnaire, "Symptoms" and "Daily Activity" subgroups were the most apparent to correlate with VR decrease. The reverse correlation was observed between the degree of VR increase after selecting the adequate control therapy in patients with baseline VR < 60 beats/min and improvement of the total AFEQT score as the treatment outcome. The strongest reverse correlation was observed between VR increase percentage and score improvement in "Daily Activity" subgroup. The correlation between the EQ-VAS score increase in EQ-5D-5L system and VR change level due to therapy was insignificant, and that can be justified by the non-specific nature of this life quality assessment tool and the dominance of underlying disease impact on patients' answers.

Conclusion. As a result of the study, the correlation relationship was established between the degree of VR change and life quality improvement in elderly patients with permanent AF after selection of VR control therapy. For the baseline VR value > 90 beats/min, this relationship is positive. For reversible bradycardia, the correlation between the degree of VR increase as a treatment result with life quality improvement in elderly patients is negative. The most significant life quality improvement after therapy adjustment was achieved with VR value increase by a minimum of 8.3%. The survey examination of elderly patients while selecting the VR range, life quality assessment is appropriate to be included according to AFEQT questionnaire score that correlates with VR value (the total score, the scales "Symptoms" and "Daily Activity").