Comparison of long-term radial artery occlusion via distal vs. conventional transradial access (CONDITION): a ... - BMC Medicine

To our knowledge, the present study was the first large-scale randomized controlled study to evaluate the effect of dTRA on the incidence of long-term RAO. The results concluded that dTRA could significantly reduce the incidences of long-term RAO, bleeding and mEASY type ≥ II haematoma, although the rate of successful puncture in a single attempt was lower.

Since Professor Kiemeneij F reported the experience in coronary intervention via the left dTRA, several randomized controlled studies have compared the safety and efficacy of cardiovascular intervention via the dTRA and the TRA, including the incidence of RAO [1, 10, 18,19,20,21]. Although most RAO is asymptomatic, an occluded radial artery limits the further use of the radial artery for the repeated catheterization approach and the conduits in patients undergoing coronary artery bypass graft and radial arteriovenous fistula in renal insufficiency in the future. Therefore, preventing and managing RAO is very important [22]. However, the incidences of RAO accrossing studies were inconsistent. In addition, most randomized studies evaluated the incidence of RAO at 24 h after the procedure or before discharge [18, 23,24,25]. The pooled result in a meta-analysis revealed that the dTRA could reduce the risk of in-hospital RAO (RR: 0.32, 95% CI: 0.19–0.53, P < 0.001) [26]. The DISCO trial concluded that the incidence of forearm RAO was low, and was not different between two groups (TRA 0.91% vs dTRA 0.31%; P = 0.29) at discharge. However, it needs to be emphasized that systematic implementation of best practices was used to reduce the incidence of RAO in the study, such as reduction of the sheath's outer diameter, adequate procedural anticoagulation, nonocclusive haemostasis, and a minimal pressure strategy with short haemostasis time. These measures may contribute to the decline in the rate of RAO. However, the incidence of RAO in TRA and dTRA was reported 8.4% vs. 0.71% in the DAPRAO trial, and 7.9% vs. 3.7% in the ANGIE trial, which was significantly higher than that in the DISCO trial. In our study, we did not take special measures to prevent RAO and found the forearm RAO rate was 6.7% in TRA and 2.5% in dTRA at 24 h post-procedure.

Studies have found that spontaneous recanalization might occur in approximately 30% of patients with RAO in late follow-up [7, 27]. In fact, the long-term outcome of RAO can better reflect the value of the dTRA in the prevention of RAO. To date, there are few randomized controlled studies comparing the incidence of late RAO between the TRA and the dTRA, and the sample size is relatively small, except for the sample in the ANGIE trial [19, 20]. The DAPRAO trial included 282 cases to evaluate the superiority of dTRA for the prevention of RAO and concluded that dTRA can reduce the incidence of RAO at both 24 h and 30 days after a coronary procedure [20]. However, the sample size was relatively small, and only patients with RAO at 24 h were reevaluated after 30 days. As the largest randomized controlled study evaluating the incidence of late RAO, the ANGIE trial included 1042 cases that were followed for a median of 46 days [19]. They found that the incidence of forearm RAO was significantly lower in the dTRA group than in the TRA group (3.7% vs. 7.9%, P = 0.01). However, in this study, 15.9% of patients had previously undergone a right dTRA or TRA intervention, and 62.7% of cases required the use of a 5 Fr sheath. The rate of successful sheath insertion was only 78.7% in the dTRA group, which was significantly lower than that in the TRA group. In addition, early RAO before discharge was not reported in the study, and the rate of loss to follow-up was relatively high (23.6%). Repeated ipsilateral radial artery access might aggravate damage to the radial intima and increase the thickness of the intima, which might decrease the successful puncture rate and increase the incidence of access-related complications [28]. In addition, a 6 Fr sheath was indiscriminately used in all patients in our study, which may greatly increase the sheath-to-vessel mismatch in patients undergoing repeated ipsilateral radial artery access. Therefore, we compared the incidence of long-term RAO between dTRA and TRA in patients without a history of ipsilateral radial artery catheterization. In the present study, most patients used 6 Fr sheath, 26.3% of patients underwent coronary intervention, and the incidence of long-term RAO was significantly lower in the dTRA group (ITT: 0.8% vs. 3.3%; PP: 0.6% vs. 3.4%, P < 0.05).

Compared with that at 24 h after the procedure, the rate of spontaneous recanalization of RAO at the 3-month follow-up was higher in both the TRA group and the dTRA group (ITT: 50.7% in TRA and 68.0% in dTRA; PP: 41.4% in TRA and 62.5% in dTRA). Previous studies have shown that the rate of recanalization of RAO was approximately 30%; however, in most studies, the follow-up time was approximately 1 month [27]. In the present study, we observed a higher rate of recanalization of RAO and hypothesized that the rate of recanalization might further increase with a longer follow-up time. However, we did not obtain RAO data at the 1-month follow-up, which was one of the limitations of the study. During the follow-up, we also found that patients without early RAO before discharge were prone to no longer occur long-term RAO in either TRA or dTRA.

In the DISCO RADIAL trial, the incidence of dRAO was only 0.46% in the dTRA group after a series of preventive measures for RAO [18]. However, the rate of dRAO was 1.4% in the present study. The distal radial artery was relatively small, and the mismatch between the sheath and the vessel was an independent risk factor for RAO and/or dRAO [29, 30]. To determine whether a slender sheath is superior to a conventional artery sheath in terms of reducing the incidence of dRAO, the ongoing SMART trial (NCT05501925) might provide an answer.

Interestingly, RAO combined with dRAO occurred in 6 patients in the TRA group and in 2 patients in the dTRA group. The occurrence of RAO combined with dRAO in the dTRA is easy to understand. We speculated that the first reason for RAO combined with dRAO might be reverse thrombus formation after RAO. Another reason might be the earlier separation of the superficial palmar arch from the radial artery, which led to the puncture site of the TRA actually being located at the distal radial artery region. Then, the sheath might damage both the conventional radial artery and the distal radial artery.

Although the puncture success rate in the dTRA group was high (96.0%), it was still significantly lower than that in the TRA group (98.5%), and the puncture time was longer. Since 2019, approximately 3000 CAG or PCI procedures via the distal radial artery have been successfully performed in our centre. Main operators have overcome the puncture learning curve and have extensive experience in performing distal radial artery puncture [31].

In recent years, several studies have investigated the impact of the dTRA on the radiation exposure. In the opinion of some scholars, the dTRA should be related to the higher fluoroscopy time and radiation exposure [32]. However, the results were inconsistent. For example, in the ANGIE trial, the total procedure time was longer (14 min vs. 11 min, P < 0.001), and the dose area product (DAP) was higher (32,729 vs. 28,909 cGy/cm², P = 0.020) in the dTRA group than the TRA group. However, the fluoroscopy time was not significantly different between the dTRA and TRA groups. In a meta-analysis, the authors concluded that the procedure time and the fluoroscopy time were both longer in the dTRA than in the cTRA [33]. Compared with fluoroscopy time, the DAP might be a more comprehensive indicator of radiation exposure. In the present study, there were no significant differences in the total fluoroscopy time or radiation dose between the two groups. Further well-designed studies are needed to confirm whether the dTRA significantly increases radiation exposure.

Regarding other vascular access-related complications, numbness of the hand was common in the dTRA group. The superficial branch of the radial nerve passes through the AS region. Puncture in the AS might damage the superficial branch of the radial nerve, which reminded us to prevent causing a radial nerve injury during the puncture. Compression haemostasis can also cause the numbness of the fingers, but the symptoms usually disappear soon after removing the elastic bandage. However, there were no radial nerve electrograms or ultrasound images to verify this hypothesis in the present study. In addition, although dTRA can reduce the rate of RAO, it might still damage the radial artery and increase the thickness of the intima.

Study limitations

First, there was no uniform compression haemostasis between the two groups. In the present study, the TR band was used in the TRA group. Due to the lack of special haemostatic devices for dTRA, an elastic bandage was used for haemostasis in the dTRA group. Theoretically, the rate of RAO may be higher with elastic bandages than with compression devices. However, even with the use of elastic bandages for haemostasis, we found a significantly lower rate of RAO in the dTRA group than in the TRA group. That is, the rate of RAO will be lower in the dTRA group with better compression haemostasis. Second, patent haemostasis was not performed in either group, which may have also influenced the outcomes. In "real-world" practice, patent haemostasis is not always feasible in high-volume tertiary centres because it needs more human resources and time. We acknowledge the potential adverse impact without patent haemostasis, but differential bias between groups can be avoided as both TRA and dTRA groups did not use patent haemostasis in our study. Therefore, we think the impact is controllable and relatively acceptable. Third, this study was performed by physicians who were experienced in performing puncture via the TRA and dTRA, which might have increased the puncture success rate and reduced the incidence of radial artery injury. Fourth, according to the previous literature, the initially estimated sample size was 692. In 2022, two large-scale randomized controlled trials with lower difference of incidence of RAO were successively published during our study. We realized that the sample size estimates were overly optimistic in the study design. The statistical power may not be sufficient based on the original estimation protocol. Therefore, we increased the sample size to 801. The incidence of long-term RAO was 3.3% in the TRA group and 0.8% in the dTRA group in the present study as an ITT analysis. Based on the actual outcomes and sample size (801), the post hoc power of the test was only 70%. In principle, we should consider adaptive study of adjusting the sample size when we design the study. Finally, although all patients underwent ultrasound examination before the procedure, this study protocol did not limit the internal diameter of the vessel at the puncture site. As reported, the vessel diameter in AS is significantly smaller than that in conventional radial artery puncture sites, and small vessels may reduce the puncture success rate and increase the risk of RAO [7, 34, 35]. Therefore, preoperative assessment of the internal diameter of the artery by ultrasound and choosing the appropriate patients might further reduce the incidence of RAO.

Adblock test (Why?)