Preserved autonomic regulation in patients undergoing transcatheter aortic valve implantation (TAVI) – a prospective, comparative study

Abstract

Heart rate and blood pressure variability as well as baroreflex sensitivity (BRS) lead to additional insights on the patients' prognosis after cardiovascular events. The following study was performed to assess the differences in the postoperative recovery of the autonomic regulation after transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). Fifty-eight consecutive patients were enrolled in a prospective study; 24 underwent TAVI and 34 SAVR. BRS was calculated according to the Dual Sequence Method, heart rate variability (HRV) was evaluated using standard linear as well as nonlinear parameters. HRV and BRS parameters were reduced after surgery in patients with SAVR only (meanNN: p<0.001, sdNN: p<0.05, Shannon: p<0.01, BRS: p<0.01), while these indexes were preserved in patients after TAVI. Simultaneously, an increased complexity of blood pressure (BP) in SAVR patients (fwShannon: p<0.001, fwRenyi4: p<0.001), but not in TAVI patients was recorded. In this study we were able to demonstrate for the first time that, in contrast to patients undergoing conventional open surgery, there are fewer alterations of the cardiovascular autonomic system in patients with TAVI.

Impact of cardiac surgery on the autonomic cardiovascular function

“…Both factors can be assumed to alter the respiratory-induced blood pressure variation. A preoperatively reduced normalized low-frequency power of blood pressure variability as compared to AVR patients is in line with this observation [13].…”

“…We previously analyzed the patients undergoing the depicted interventions by means of their HRV, BPV, and BRS in pairwise settings, i.e., AVR vs MVR and AVR vs TAVI [12,13]. The present contribution pooled together and widened the mentioned studies in terms of implicated patients, applied methods, and finally drew conclusions.…”

“…More details regarding the calculation of the used parameters and their informative value can be found in [17] and [16]. Retzlaff et al [12,13] applied some additional univariate features (selected HRV features and features related to the BPV) which, due to the uniformity of the results obtained by using those features compared to the selected ones, were not separately considered in this contribution.…”

Impact of type of intervention for aortic valve replacement on heart rate variability

“…After both coronary artery by-pass surgery and valvular surgery, the greatest impairment of cardiac autonomic function and the maximal decrease of HRV parameters is reported to occur at about the sixth postoperative day, persisting rather low at 15 days after intervention [9,15], approximately the time our SAVR patients had been studied with a 24-h Holter recording. At the same time period after intervention, patients submitted to transfemoral or transapical valve implant had more preserved or normal HRV parameters, suggesting that it was the kind of intervention that likely leads to a lower involvement of cardiac autonomic nervous system.…”

“…In coronary artery disease, some degree of autonomic derangement has been anyway recorded also in patients submitted to elective percutaneous coronary angioplasty, with variable levels of HRV decrease depending on different localization of coronary lesions [14]. To our best knowledge, only one studyperformed on a small number of patients -has made as yet a comparison of HRV after surgical aortic valve replacement (SAVR) versus tranfemoral (TfAVI) and transapical (TaAVI) aortic valve implantation: it confirmed the negative effects of surgery and a preservation of various HRV indexes after percutaneous valve implantation [15]. Anyway, in the cited study the two percutaneous approaches for aortic valve replacement have not been considered separately in spite of their different invasiveness.…”