Non-femoral focused transaxillary access in TAVI: GARY data analysis and future trends

As transcatheter aortic valve implantation (TAVI) continues to expand to a broader and lower risk patient population and operator experiences increase constantly, the use of the transfemoral (TF) access is becoming even more dominant [1, 2]. The transfemoral access is the most chosen primary access as it is secure and the available catheter equipment is developed for this particular access strategy. This is also facilitated by data indicating that transapical (TA) and transaortic (TAo) approaches might be related to an increased risk of access complications, 30-day mortality, and stroke compared to the transfemoral (TF) approach [3, 4]. In the recently published guidelines only, the transfemoral access has a class I indication for TAVI. Non-transfemoral TAVI is only indicated (class IIb) in patients who are inoperable for SAVR and unsuitable for transfemoral access [5]. Alternative access routes, such as transaxillary (TAx), transcaval, or transcarotid access, are of growing interest for patients with relevant iliofemoral atherosclerotic disease, small iliofemoral diameters, or tortuous vessels in whom TF access is not feasible [6, 7]. The TAx access route offers an access vessel that has a diameter usually greater than 6 mm, a low calcification profile, and a short distance to the heart and is located superficially, giving the vessel a similar profile to the femoral artery [8] and the option for a procedure without general anesthesia. Comparing TAx and TF access in high-risk patients, the results regarding 30-day mortality and vascular complications were comparable [9].

Within this analysis, we aimed to investigate the adoption and outcomes with non-TF TAVI access in Germany, focusing on the axillary access route.

Although TF access is the recommended approach for TAVI, recently 6–8% of procedures in Germany were performed via a non-TF access due to anatomical peculiarities impeding TF access [5, 11]. Several factors, e.g., expansion of the TAVI indication to lower risk patients, improved deliverability of devices, up-front debulking to facilitate TF access even in hostile vascular situations, and better survival, have led to an increase of TF-amenable patients in recent years [12, 13]. In contrast to the FRANCE and STS/ACC TVT registries, in which the TAx access has gained popularity, it remained to be chosen rarely in GARY [1, 14]. Since the TA access has always been the most used alternative access strategy in Germany, it is not surprising that it remains to be the most chosen non-TF access strategy in our collected data. Both the TA and TAo access require a mini-sternotomy or a mini-thoracotomy and need to be performed under general anesthesia [11, 15]. For this reason, TA and TAo have been considered to be a more invasive procedure leading to increased complication and mortality rates [16, 17]. These fundamental disadvantages of thoracotomy and general anesthesia are not present in the third access strategy evaluated, the TAx access, which can be considered less invasive and thus potentially less harmful. Because we found a better 30-day survival compared to TA and better 1-year survival compared to TAo, because the TA/TAo patients required multiple blood products more often and the ICU and length of hospital stay were shorter after TAx access despite an increase in vascular complications, we would advocate the TAx access as the first alternative access site. However, because expertise is of particular importance, it may be useful for each heart team to gain experience with only one of the non-TF access strategies to safely treat patients who are not suitable for the standard TF-TAVI approaches.

In a subgroup analysis of a meta-analysis comparing randomized TAVI vs. Surgical Aortic Valve Replacement (SAVR) trials, the comparison of all-cause mortality between 30 days and 5 years revealed a lower incidence in patients treated via the TF approach compared to non-TF TAVI patients [18]. Siemieniuk et al. published a meta-analysis comparing TA patients to SAVR patients, which found that TA TAVI was associated with higher mortality and stroke rate [19]. To the best of our knowledge, there is currently no particular comparing the outcomes of TAVI patients with non-TF access routes other than the TA approach to those of SAVR patients. A prior analysis of TAVI patients, encompassing data from the GARY registry for the years 2011 and 2012, revealed that the chosen access route demonstrated no discernible influence on patient mortality [20]. A further analysis of the GARY registry published in the European Heart Journal comparing low-risk TAVI and SAVR patients showed a similar 1-year survival and higher in-hospital survival for TAVI patients [21]. Within this analysis, only a fraction of the TAVI patients were treated via non-TF access route and the authors state that non-TF access routes will have no impact on data analysis.

As a matter of concern, in previous studies, the TAx access was associated with a higher incidence of stroke. Looking into detail, the stroke incidence described in registries is just slightly above 2%, but Chung et al. described a stroke incidence of above 6.5% in 4219 TAx patients in the STS/ACC TVT registry [22, 23]. Potential risk factors for increased cerebral injuries could be manipulation/occlusion of the ostium of the vertebral artery and manipulation of the aortic arch and of the carotid/brachiocephalic ostia, possibly leading to embolism and decreased perfusion [24]. However, GARY data did not show a significant difference of stroke rates among the three access strategies. TAx access can be gained by surgical cutdown or percutaneous puncture. In TF percutaneous approach reduces the procedure time and the length of hospital stay compared to surgical cutdown without disadvantages regarding major access complications and survival [25‐27]. Within the conducted analyses, no significant differences in the clinical outcomes comparing percutaneous and surgical cutdown TAx were found, but numerically more vascular complications after percutaneous access. This aligns with the data recently published from an analysis of the STS/ACC registry. Chung et al. described an increased incidence of vascular complications after percutaneous access, but without an increase in life-threatening bleedings [22]. In our landmark analysis, surgical cutdown patients had a significantly better 1-year survival (Fig. 4b). An explanation might be that the percutaneously approached population suffered insignificantly more strokes and transient ischemic attacks, which are known to result in a decreased 1-year survival after TAVI [28, 29].

The advantage of shorter procedure time and shorter length of hospital stay, which is seen after percutaneous femoral access, did not occur in our percutaneous TAx population. The procedure time of percutaneous TAx access is often prolonged by additional safety measures, eliminating this advantage over surgical cutdown. Overall, no clinically relevant and statistically significant differences were identified. Therefore, the choice to gain the TAx access percutaneously or by cutdown should be based on the skills of the operator and the anatomical challenges of the individual patient.

The propensity score-weighted analyses suggest that it may be reasonable to consider TAx access first in patients who are not suitable for TF-TAVI, because the 30-day survival rate was higher compared with TA access and the 1-year survival rate was higher compared with TAo access. More vascular complications occurred after TAx access without an increase in ICU a hospital length of stay. Numerically higher stroke rates after TAx access are of concern and require more investigation. It remains important for the heart teams to offer alternative access modalities for patients not amenable to the standard TF-TAVI approaches.