This sub-analysis of the RIVA-PCI trial [9] aimed to investigate in-hospital bleeding and cerebral and coronary event rates depending on femoral or radial access for coronary intervention in patients with AF. Meta-analyses showed that in patients undergoing coronary angiography and PCI, radial access (TRA) was associated with a significant reduction in the risk of bleeding, vascular complications, and mortality compared to femoral access (TFA). The risk of stroke or MI was comparable in patients with radial or femoral access [6, 10]. A considerable number of these studies investigated coronary interventions performed in the setting of acute coronary syndrome (ACS). Moreover, it is still controversial whether the benefits of radial versus femoral access for coronary angiography and PCI are based on the choice of access site itself, the experience of the operator, or other mechanisms.

The data underlying the present investigation derive from the RIVA-PCI registry and therefore address a cohort of patients with AF who underwent PCI in the setting of both acute and chronic coronary syndrome. The study was conducted at multiple centers, allowing any significant differences in the selected parameters of bleeding and cerebral event rate to be attributed with high confidence to the selected access route. The study focused on a homogeneous patient population with AF, which adds to the growing evidence comparing these two access sites in patients undergoing PCI.

In this study, the use of femoral access for PCI was associated with a higher bleeding rate (BARC 2–5) compared to the radial access group (4.2% vs. 1.5%, p < 0.01). This is caused mainly by significantly more bleeding that requires transfusion or surgical therapy (BARC 3). These differences were observed peri-procedurally. This is particularly remarkable considering that in the TRA group, significantly more patients were prescribed triple therapy at the time of discharge relative to the TFA group, which predominantly received dual therapy. Our results are consistent with the data from a recently published meta-analysis of 31 randomized controlled trials (RCTs) comparing radial versus femoral access sites for coronary angiography and PCI. In that meta-analysis, radial access was associated with a significant reduction in major bleeding compared to femoral access (odds ratio [OR] 0.53, 95% CI 0.42–0.66). These findings were consistent regardless of clinical characteristics or whether coronary angiography was performed with or without PCI [6]. A similar OR of 0.55 was calculated in the meta-analysis by Gargiolu et al., which was published in 2022 [5]. The OR for the defined endpoint of BARC 2–5 bleeding in our analysis is 0.36 [95% CI 0.18–0.68]. These findings should be taken into consideration when selecting the optimal access site for PCI, particularly in patients who may be at higher risk for bleeding complications. In our analysis, the number needed to treat (NNT) was 37 to avoid relevant bleeding that needed to be treated (BARC 2–5). Regardless of the puncture technique used and any additional measures taken to limit vascular complications, there is mounting evidence that the superior safety profile of TRA over TFA persists. While advancements in ultrasound guidance and micropuncture needles may reduce the incidence of vascular complications after TFA, TRA still appears to yield better outcomes in terms of safety [11, 12]. Regarding the use of ultrasound guidance for the TFA procedure, we did not record data on its utilization in the registry. Therefore, we do not have specific information on whether ultrasound guidance was employed or its potential impact on bleeding events.

The incidence of TIA and stroke, however, was similar between the groups. Although the TRA is associated with an increased rate of subclinical cerebral embolism, no differences in the rates of clinically relevant strokes have been demonstrated in large randomized studies [8, 13, 14]. This may be due to the low incidence of periprocedural strokes. With radial access, there could be an increased risk of stroke due to catheter manipulation in the extracranial cervical vessels, but on the other hand, this risk also exists with femoral access and catheter manipulation in the aortic arch, especially in the presence of plaques in the thoracic aorta. In our study, two strokes occurred in each group, two ischemic strokes in the femoral access group (0.2%) and one ischemic stroke and one stroke of unknown type in the patient cohort with radial access (0.3%). As no systematic neurological examination was performed post-intervention, as in most of the other studies, the true event rate may be higher. The following consideration should be mentioned at this point: even to investigate a 50% increase in stroke rate with a stroke incidence of 0.2% and a statistical power of 80%, nearly 80,000 patients would be required.

The findings of this study also suggest that the selection of access site, either TFA or TRA, did not significantly impact the risk of stent thrombosis or myocardial infarction. The occurrence of stent thrombosis was observed in 0.2% of patients in the TFA group and 0.3% of patients in the TRA group, with no statistically significant difference between the two groups (p = 0.93). Similarly, myocardial infarction was seen in three cases in the TFA group and one case in the TRA group, with no significant difference between them (p = 0.36). This is consistent with previous research indicating comparable outcomes between the femoral and radial approaches in terms of coronary events [5]. The studied data additionally revealed that there was no difference in all-cause mortality between groups. During the time until discharge, 12 out of 1636 patients died—eight in the TFA group (six due to cardiac death, two unknown) and four in the TRA group (three due to cardiac death, one unknown). There was no statistically significant difference between groups (0.9% vs. 0.5%, p = 0.31). The mean length of stay after PCI until discharge was 4 days, and there was no significant difference between groups. A meta-analysis published in 2022 showed that all-cause mortality was lower with TRA than with TFA at 30 days (1.6% versus 2.1%; HR, 0.77 [95% CI 0.63–0.95]; p = 0.012), with a number needed to treat to benefit (NNTB) of 214. Landmark analyses demonstrated that the benefit in favor of TRA was mainly observed in the first few days after the index intervention (0.5% vs. 0.8%; HR 0.64 [95% CI 0.46–0.90]; 0.010) [5]. Our data roughly correspond to these results, although our sample size was significantly smaller, thereby increasing the susceptibility to type II error. Major bleeding can be considered as a mediator of all-cause mortality (indirect effect), especially in patients with moderate or severe baseline anemia [15].

The access route was chosen by the interventionalist, and therefore it is possible that sicker, possibly more complex patients were more likely to receive their PCI through the femoral access. As shown in Fig. 1, patients with high CHA2DS2VASc-score (5–9) were more likely to receive a femoral approach. Patients treated via the TFA also had a higher prevalence of heart failure and previous CABG surgeries. Interventionalists may have opted for the femoral access route more frequently for sicker patients. In a noteworthy study, a model was developed and internally validated to predict the risk of vascular access site complications during percutaneous coronary intervention (PCI) via a transfemoral approach. The findings of this study illustrated that patients with the lowest risk for access site complications predominantly received transradial arterial access, whereas those with the highest risk were more likely to undergo transfemoral arterial access. This underscores a potential discrepancy in the allocation of arterial access strategies, highlighting that the rational employment of transradial arterial access as a means to mitigate vascular access site complications is suboptimal and warrants considerable enhancement in its application. This insight is crucial as it sheds light on the need for refined strategies to optimize the use of transradial arterial access, particularly for patients at higher risk, to prevent complications and improve overall patient outcomes [16].

Analysis of in-hospital bleeding, cerebral and coronary events in the RIVA-PCI trial population, based on the access route (femoral/radial) for coronary intervention. In addition to the absolute numbers of affected patients, event rates are given as percentages. The case number of patients with femoral access (TFA) was 854, that with radial access (TRA) 782

Overall, this study suggests that using femoral access during PCI in patients with AF may be associated with a higher in-hospital bleeding rate compared to radial access, but there is no difference in cerebral or coronary event rate. These data is in line with previously published results of comparisons between both access routes, which, however, predominantly originated from patients who received PCI for acute coronary syndrome and were not all affected by AF. The data here provided constitute an examination of “real world” practices in an environment with similar rates of radial and femoral access and inclusion of a full spectrum of CAD presentations. Therefore, further research is needed to confirm these results and to determine which patients are most likely to benefit from each access site.