The effect of chronically occluded coronary artery recanalisation on baroreflex sensitivity and left ventricular systolic function

Background: Recanalisation of chronic total occlusion (CTO) of a coronary artery can be reflected by improvements in various clinical parameters. Revealing increased parasympathetic activity would constitute an additional argument for performing this procedure. Aim: To assess the effect of CTO recanalisation on baroreflex sensitivity (BRS) and left ventricular ejection fraction (LVEF) in stable symptomatic patients with coronary artery disease. Methods: BRS (spectral analysis, transfer function, Blackman-Tukey algorithm, 0.03 Hz bandwidth Parzen window) and LVEF (echocardiography, Simpson's method) were analysed in 23 patients: one day (R1) before, one day (R2) after, and three months (R3) after CTO recanalisation. Patients were divided into two groups: those with depressed (≤ 3 ms/mm Hg) or preserved (> 3 ms/mm Hg) BRS. Results: Significant BRS changes were observed in the study group compared to baseline values (p = 0.016). In the patients with a depressed reflex, BRS in R2 was similar to R1 and almost doubled in R3 (p = 0.018). In the patients with a preserved reflex, BRS significantly decreased in R2 (p = 0.024) and returned to the baseline value in R3. The behaviour of LVEF was homogenous in the groups, showing an increase from R1 to R3. Conclusions: The improvement in autonomic nervous system activity after successful CTO recanalisation is reflected by an increase in BRS, and the changes are dependent on the baseline value of the measurement: patients with a depressed BRS before recanalisation present a greater BRS improvement than patients with a preserved BRS. The CTO recanalisation leads to the improvement of LVEF in both groups.