Comparison between two protocols for deflation of the TR band following coronary procedures via the radial route

* Corresponding author at: Department of Cardiology, Sultan Qaboos University Hospital, PO Box 38, Alkhod, Muscat 123, Oman. E-mail address: moc.liamg@radanlinus (S.K. Nadar).

This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Abstract

Aim

Coronary interventions are increasingly being performed via the radial rather than femoral route because of the lower complication rate. Compression devices such as the TR band are used to achieve hemostasis after the procedure. At present, there are no clear protocols for the deflation of the band. In this study we compared two protocols (early deflation with increased intervals vs. late deflation with smaller intervals) in terms of total time to band removal and complications, and patient and staff satisfaction.

Methods

All patients who underwent a transradial coronary procedure and had a TR band fitted were enrolled into the study. The TR band was applied using the patent hemostasis method (2 ml air pushed in after the radial pulse appears on pulse oximetry after full occlusion with 16 ml air). Patients were randomly assigned to either protocol. Protocol 1 involved removal of 2 ml of air starting 1 hour after the sheath removal and then removal of 2 ml every 30 minutes until the band came off. Protocol 2 involved removal of 4 ml of air 2 hours after the sheath removal and then further 4 ml of air every 15 minutes until the band came off. Patient and staff satisfaction was measured with a visual analogue scale.

Results

A total of 174 patients were recruited (mean age, 60 ± 11 years; 127 male, 47 female). The baseline characteristics including total heparin dose and type of procedure, in the two arms were the same. Protocol 2 (n = 84) was associated with a significantly lower time to TR band removal as compared to protocol 1 (n = 90; 201 ± 43 min vs. 274 ± 54 min; p < 0.001). There was no difference in complications such as bleeding or hematoma formation between the two groups. Patient satisfaction was the same between the two groups. However, the staff preferred protocol 1 (p = 0.01).

Conclusion

A protocol of delayed initiation of TR band deflation followed by quick deflations is associated with a lower time to band removal with no increase in bleeding complications or patient satisfaction. However, the staff preferred longer intervals between deflations.

Coronary angiography with or without percutaneous coronary intervention is the mainstay of management of patients with coronary artery disease [1]. There are two main access routes–the femoral or radial artery approach. Traditionally, the femoral artery was the main route of access; however, over the past decade, the radial artery has been replacing the femoral artery as the preferred route despite this being slightly more technically challenging and having a steeper learning curve [2]. Indeed, in 2015 in the UK, 80% of coronary procedures were performed via the radial route [3]. The radial approach is associated with a lower bleeding risk and allows immediate mobilization of the patient after the procedure and thereby significantly reducing the length of hospital stay [4]. It has therefore been shown to be more cost-efficient [5] and associated with better outcomes especially in acute coronary syndromes (ACS) [6] as compared to femoral access. At our institution, the radial artery is the primary access route for all cases.

There are many methods that can be used to obtain hemostasis of the radial artery after sheath removal [7]. These include manual pressure and a pressure bandage, or compression bands such as the TR band (Terumo Inc., Tokyo, Japan), the RADstat (Merit Medical Systems, South Jordan, UT, USA), helix device (Vascular Perspectives, London, UK), etc. One of the complications of using the radial route is the potential for radial artery occlusion, which would limit repeated use of this route [8]. The patent hemostasis method, where hemostasis is achieved whilst at the same time, maintaining the patency of the radial artery has been shown to reduce the risk of radial artery occlusion [9]. The use of compression bands helps us to be sure that we are using patent hemostasis.

At our center we use the TR band to achieve hemostasis after sheath removal. This device involves the inflation of a small balloon that compresses the artery. This balloon is then deflated over time. Despite the TR band being widely used, there are no standardized protocols available for the safe deflation of the band and different institutions use different locally generated protocols [10].

The protocols generally involve either early initiation of deflation with longer intervals or later initial deflation followed by shorter intervals of deflation thereafter. The official protocol by Terumo (the manufacturers of the device) suggests that deflation should commence after 1 hour if 50 units/kg or less of heparin was given or after 2 hours if a higher dose of heparin was given. After this, 3–5 ml of air should be removed every 10–15 minutes [11].

At our institution, all patients are given a minimum of 70 units/kg of heparin. We hypothesized that standard protocol of early initiation of deflation of air (within an hour) but with longer intervals of deflation would be inferior to the modified protocol that involves a delayed initiation but shorter intervals. Recently, there have been trials which show that an accelerated protocol that starts almost 30 minutes after the sheath removal is safe without an increase in bleeding complications [12,13] but with overall longer time to removal. However, other groups have demonstrated increased bleeding with these accelerated protocols [13,14] and suggested the delayed protocol.

The aim of our study therefore was to compare this modified protocol of early initiation of deflation of the TR band with the standard protocol of delayed initiation of the band and compare the total time taken for band removal and assess the safety and complications such as bleeding between the two protocols. We also sought to see which protocol would be preferred by patients and staff.

2. Methods

All patients older than 18 years who were admitted in the coronary care unit (CCU) or general cardiology ward, underwent a transradial coronary procedure, and had a TR band fitted after sheath removal were enrolled into the study. Recruitment started in January 2018 and continued until August 2018. However, we excluded patients who had a radial procedure via the radial artery studied as we felt that radial artery damage caused by a previous procedure might affect the bleeding and complication rate.

Patients were included irrespective of the procedure (diagnostic coronary angiography or percutaneous coronary intervention), or indications (stable coronary artery disease or acute coronary syndrome). We excluded patients who had the TR band accidentally removed prematurely or because of bleeding or hematoma prior to deflation, and those who did not gave consent.

The TR band was applied using the patent hemostasis method, which has been described previously [15]. In short, the TR band is inflated with 16 ml of air and a pulse oximetry is applied on the thumb of the hand where the procedure was performed. The ulnar artery is occluded until the pulse waveform disappears on the pulse oximetry monitor. Then, 2 ml of air is removed sequentially from the TR band while the ulnar artery is still occluded until a pulse waveform appears on pulse oximetry. Finally, 2 ml of air is pushed back in to the TR band and left in place until deflation starts as per the selected protocol. Patients were randomly assigned to one of two protocols. Randomization was done manually with all the printed protocols folded unmarked and mixed together in a box. A printed sheet was picked at random from the box for each patient. It was not possible to identify the protocol prior to picking from the box.

Protocol 1 involved removal of 2 ml of air starting 1 hour after the sheath removal and then removal of 2 ml every 30 minutes until the band came off. Protocol 2 involved removal of 4 ml of air 2 hours after the sheath removal and then further 4 ml of air every 15 minutes until the band came off. If bleeding was observed, 2 ml of air was further injected into the sheath. The patients were sent from the catheter laboratory back to the ward with a printed protocol explaining the protocol and with the expected time of each deflation clearly mentioned. Informed consent was obtained from all patients prior to enrolling in the study. No further wrist immobilizers were used along with the TR band. At the time of band removal, all patients had their radial artery palpated to look for any immediate occlusion.

Patient comfort and staff satisfaction was performed using a visual analogue scale. Patients were asked to fill the scale at the end of sheath removal. This was on a scale of 1–10, where 1 was extremely comfortable and 10 was extremely uncomfortable. With regard to staff satisfaction, it could not be done for each patient as there were multiple nurses involved in the care of a particular patient and across each shift. Therefore, at the end of the study, the nurses involved were asked to fill the visual analogue scale to rate their experience with each protocol. They had to rate on a scale of 1 to 10 the ease of each protocol, in which 1 was extremely easy and 10 was extremely difficult. We had only included nurses who had used both protocols on at least 10 patients to fill in this survey.

Our previous observations had shown that with our existing protocol the mean time to band removal was about 275 ± 30 minutes. The sample size calculated to find a difference of at least 15 minutes with an alpha error of 0.05 and power of 90%, was 168.

Ethics approval was obtained from the hospital ethics committee, and the study was performed according to the guidelines of the Declaration of Helsinki. The study has been registered at clinicaltrials.org (identifier number NCT03380065). All statistical calculations were performed using SPSS version 22 (SPSS Inc., Chicago, IL, USA). Student t test was used for normally distributed data and Mann–Whitney U test was used for nonnormally distributed data. Chi-square test was used for categorical values. A p value

3. Results

A total of 200 patients were recruited into the study. The 26 patients who had incompletely filled their forms were excluded from the analysis. None of the patients approached had refused consent. The data from 174 patients were analyzed. The mean age of the patients was 60 ± 12 years, of whom 72% were male. The baseline characteristics in the two arms were the same ( Table 1 ). All patients had received a minimum of 70 units/kg of heparin along with a loading dose of clopidogrel (600 mg) and aspirin (300 mg) as is standard protocol in our institution for patients undergoing coronary angiography with a view to proceeding for angioplasty if required. There was no difference in the number of patients receiving any glycoprotein IIb/IIIa inhibitors in the two groups. There was no difference in the time interval from the last heparin dose to sheath removal and application of the TR band in each group. At the time of band removal, all patients in the study had their radial arteries palpable. However, we did not perform Doppler studies to confirm patency.

Table 1

Baseline characteristics of the patients.