Background: Recanalisation of the chronic total occlusion (CTO) of coronary artery is not a routine procedure. The benefits of CTO recanalisation have not yet been definitively established. This may be due to inappropriate identification of patients who benefit the most from the CTO recanalisation.
Aim: To assess the autonomic nervous system (ANS) parameters and left ventricular ejection fraction (LVEF) changes after the recanalisation of the left anterior descending (LAD) and right coronary artery (RCA).
Methods: Twenty three patients with CTO, stable angina and a positive exercise test result were included in the study. All subjects were admitted to the hospital for elective recanalisation of CTO. One day before the recanalisation, within the first 24 h and three months after the procedure, LVEF, baroreceptor sensitivity (WBA_BRS) and heart rate variability (HRV) measures: mRR, SDNN, pNN50, LF/HF were assessed. Results before and after recanalisation were compared.
Results: In the LAD group, initial LVEF, WBA_BRS and LF/HF values were significantly lower than in the RCA group (43 ± 11 vs. 52 ± 4%, p = 0.005; 3.1 ± 1.9 vs. 7.9 ± 5.0 ms/mmHg, p = 0.008; 1.3 ± 1.9 vs. 3.7 ± 2.6, p = 0.02, respectively). During first 24 h after the recanalisation, LVEF increase was observed in both groups. In the LAD group additional LVEF improvement was found during a long-term follow up (LVEF in the RCA group: 52 ± 4%, 56 ± 2%, 56 ± 2%; in the LAD group: 43 ± 11%, 47 ± 10%, 54 ± 9%). In the RCA group a transient decrease of WBA_BRS during first 24 h after the procedure was found (7.9 ± 5.0 vs. 5.0 ± 2.8 ms/mmHg, p = 0.09), while in the LAD group this effect was not observed. Moreover, in the LAD group a trend towards an increase of WBA_BRS was found three months after the recanalisation (3.1 ± 1.9 vs. 5.0 ± 2.8 ms/mmHg, p = 0.09). Similar trends were observed for HRV.
Conclusions: CTO recanalisation results in increased LVEF in all patients, but is more pronounced following LAD rather than RCA recanalisation. Also, the changes in the ANS parameters were more beneficial after LAD than RCA recanalisation. These findings may suggest that recanalisation of LAD is more beneficial than that of RCA.