With a global trend towards TRA, the proficiency and comfort of operators and trainees with TFA has come into question. Although TRA is now the preferred method of access for diagnostic and therapeutic procedures, there are still specific patient populations and clinical situations that require TFA.19,22,47 However, with unusually high rates of access site complications being observed in patients undergoing femoral PCI by default radial operators,32,127,128 many are questioning if evidence of the loss of transfemoral competency has begun to show.42,48,49 These apprehensions are subjectively shown by our survey in which trainees reported a lower level of comfort [6/10] with TFA, compared to TRA [9/10] and 95% of the trainees chose TRA as their default access. The commonest reasons cited by trainees for radial preference were, in order; - patient satisfaction, low complication profile, ease of closure and the training center’s “radial first” policy.
In the midst of a dramatic shift from TFA to TRA, operator experience undoubtedly becomes a major determinant of outcomes.50,51 Based on our results, while daily use of TFA was quite comparable between trainees and trainers [34% vs 35%], trainees reported a much lower exposure to the management of TFA related complications. We also queried the preference for ultrasound guidance for both radial and femoral access amongst respondents. Ultrasound guided TFA has been shown to reduce access site complications, and more than 98% of trainees reported they would use ultrasound for TFA. With less than 50% of trainers using ultrasound for femoral access and 24% "never" using ultrasound, there is a concern about the quality of teaching trainees are experiencing. This is in line with the findings by Damluji AA, et al.,52 that found similar results in femoral operators overall. This suggests that there is a systemic problem with femoral training that needs to be addressed so that safe vascular access at any site can be taught.
The phenomenon of “Campeau Radial Paradox” was central to our survey. This term was coined by Azzalini et al in 2015 after conducting a retrospective analysis of two historical cohorts of patients undergoing PCI at the Montreal Heart Institute during the periods of 1996–1998 and 2006–2008, 1,42 They concluded that while TRA has reduced vascular complication rates at an individual level, it has led to increased rates at a population level driven primarily by TFA-related complications. This was later challenged by Hulme et al in a large retrospective analysis of the British Cardiovascular Intervention Society (BCIS), showing that there were no significant differences in 30-day mortality or complication rates between centers, regardless of femoral proportion per center. 1,19 Respondents were asked regarding their belief in the proposed “Campeau paradox”; 62% of trainees and as many as 67% of trainers believe that the increased and abrupt adoption of TRA has resulted in a paradoxical spike in complications at the population level due to declining TFA expertise.
Our study sheds light on the interplay between increasingly stronger recommendations for TRA and the possible resultant decline in the quality of TFA training. While the European Society of Cardiology guidelines  recommend radial over femoral approach, the American Heart Association guidelines  did not recommend one access site over the other. However, in 2018 a radial-first approach was strongly recommended by the AHA. Faced with this increasing emphasis on TRA as the preferred choice, the apprehensions of fellows and faculty regarding lower exposure to TFA remained largely undocumented prior to this analysis. Of the trainers responding to our survey, 37.5% were “very concerned” and 31% were “somewhat concerned” about the declining exposure of trainees to TFA and related complications. Moreover, 65% of the trainers believed their trainees will not achieve the same level of expertise in TFA as their predecessors.
TFA remains a much-needed tool in the arsenal of invasive and interventional cardiologists. A 2018 Cochrane database review of 28 RCTs found there was a significantly higher incidence of cross-over with transradial approach compared to TFA.53 Thus TRA may be a preferred route of access but a sufficiently high skill level in TFA needs to be maintained in current and future training fellows. TFA remains relevant due to the ever-evolving need for large bore access. When asked about the future of TFA, most of our respondents [77% trainees and 81% trainers] believed that while TFA frequency will decline, it will continue to remain relevant as a major access point.
A major argument in favor of TRA has come from trials including RIVAL, MATRIX and RIFLE-STEACS revealing lower risk of bleeding and mortality in TRA compared to TFA.54,55,56 However, the more recent SAFARI-STEMI trial did not show significant difference in 30-day mortality or bleeding complications in TRA or TFA in primary PCI.57 This suggests that adequately trained operators can attain similar results with TRA or TFA for PCI.
We believe that access preference should take root in an understanding of the purpose of each approach and when each should be favored.58 To optimize practice in acquiring femoral access, educational programs for trainees should ensure incorporation of formal teaching, workshops, and simulators geared toward the femoral approach.59 Adequate training should also be provided in the use of fluoroscopy, ultrasound guidance and vascular closure devices, most of which have been reported to increase safety, comfort and convenience with TFA.60–64 As recommended by the American Heart Association, femoral access skills can be maintained through peripheral vascular, structural cardiac, or ventricular assist device insertion procedure.27 We believe that the apprehensions regarding the quality of TFA training expressed by trainers across the country mandate a structured approach towards ensuring adequate education in femoral access for all trainees.
Our study had a few limitations. Survey-based designs are vulnerable to biases, but since our aim was to gauge subjective parameters, we believe it was the appropriate investigative modality in absence of a better alternative. Another limitation is the small sample size.