Randomized clinical study on radial artery compression time after elective coronary angiography*

Objective to compare two compression times of the radial artery after coronary angiography with customized compressive dressing regarding the occurrence of hemostasis and vascular complications. Method a randomized clinical study was carried out in patients undergoing elective transradial coronary angiography in two study groups: (G30), whose compressive dressing was maintained for 30 minutes, and (G60), whose compressive dressing was maintained for 60 minutes, both until the first evaluation of hemostasis. Variables related to patients, procedure, occurrence of hemostasis, and vascular complications were analyzed. Patency of the radial artery was assessed with Doppler vascular ultrasonography, immediately after removing the compressive dressing and 30 days after the procedure. Results the sample consisted of 152 patients in G30 and 151 in G60. Hemostasis was evidenced in the first evaluation in 76.3% of G30 patients and 84.2% of G60 patients (p = 0.063). There were 91 immediate complications, being 53 hematomas and 38 occlusions of the radial artery. We identified 18 late occlusions, 7 (5.5%) in G30 and 11 (8.2%) in G60. Conclusion the different compression times of the radial artery after coronary angiography did not significantly influence the occurrence of hemostasis and vascular complications. Brazilian Registry of Clinical Trials (Rebec): RBR-7VJYMJ.


Introduction
The technique of transradial approach (TRA) gained importance as a strategy for the reduction of vascular complications and severe bleeding episodes in patients undergoing invasive diagnostic and therapeutic coronary procedures, with a potential impact on the reduction of mortality, especially in patients with acute coronary syndrome (ACS) when compared to the femoral artery access technique (1)(2)(3)(4)(5) .
It has proved to be an alternative to the traditional femoral artery access to promote greater comfort to patients after the procedure, possibility earlier ambulation, shorter hospital stay time and lower costs (6)(7) .
Among the complications related to TRA, radial artery occlusion (RAO) is the most common. This complication is poorly diagnosed, generally asymptomatic and with an estimated incidence of one to 10% of patients. Its occurrence makes it impossible to use the radial artery as an access option in further procedures such as a free graft for patients undergoing myocardial revascularization.
Factors such as incompatibility between the diameter of the introducer sheath and diameter of the radial artery (RA), insufficient anticoagulation, and interruption of radial artery flow during and after the procedure are considered predictors of RAO. On the other hand, the patent hemostasis after the procedure, i.e. correct pressure during compression, balancing hemostasis and maintenance of anterograde flow; the reduction in compression time; and the use of hemostatic devices to compression of the puncture site of the radial artery are preventive factors for RAO (8)(9) .
To the best of our knowledge, few publications in the literature have addressed the influence of the use of compression with customized dressing to obtain hemostasis and the occurrence of vascular complications (10)(11) . Most studies compare different dedicated mechanical devices developed by the industry that consist of pneumatic or rotational compression systems with the shape of wristbands (12)(13)(14) .
Because of the value added to the cost associated with the use of these dedicated devices, the use of customized compression dressings with gauze cushions for hemostasis at the radial access site is common in developing countries. Without standardization or recommendation based on application evidence, the technique and time of radial artery compression are determined by institutional protocols, backed by clinical experience, but not based on scientific evidence.
Thus, this study aims to compare two radial artery compression times after elective coronary angiography with customized compressive dressing (CCD) regarding the occurrence of hemostasis and vascular complications.  on the practice developed at the study site (9)   In the examination room, the patients were prepared according to institutional protocol. The technique of puncture and the choice of materials used were defined by the professional performing the procedure. After placement of the catheter at the root of the aortic artery, all patients received 50U/kg of unfractionated heparin administered intravenously; the use of spasmolytic drugs was a decision of the medical professional.

Method
After completion of the procedure, patients were randomly allocated to one of the G30 or G60 study groups.
After inclusion in one of the study groups, the radial introducer was removed by the professional performing the procedure; the compressive dressing prepared with a sterile gauze cushion and hypoallergenic adhesive tape was positioned by the researcher at the puncture site, as specified in Figure 1.

Results
In the period from August 2015 to September 2016, 743 patients underwent cardiac catheterization diagnosed through the TRA. Of these, 303 patients were included in the study, of which 152 received compressive dressing for 30 minutes (G30) and 151 for 60 minutes (G60). The flowchart of the study is presented in Figure 2.
The sample was characterized by the predominance of males, with a mean age above 60 years, with a diagnosis of stable angina, history of systemic arterial hypertension, and using antiplatelet drugs, beta blockers.
The participants had a homogeneous distribution in both groups, except for the body mass index (BMI); this index was significantly higher in the patients of G30 (Table 1) (Table 2). A total of 91 immediate complications were identified, most of them hematomas that did not require intervention for regression, with a homogeneous presentation in the groups. In the assessment of the radial artery patency immediately after removal of the compressive dressing, RAO was evident in 13.2% of G30 patients and 11.9% of G60 patients (p = 0.75).
In the evaluation performed in the 262 (86.5%) patients who returned after 30 days of the procedure, no hematomas were identified, and there was a reduction in occlusion rates, with no statistically significant difference between the groups.
No other types of vascular complications were recorded on the immediate evaluation and after 30 days.  Rev. Latino-Am. Enfermagem 2018;26:e3084.   (17) .
The compressive dressing made with a sterile gauze cushion and adhesive tape was the device used in this study to obtain hemostasis. Its efficacy as an instrument of patent hemostasis is questionable, that is, it is not confirmed if the pressure applied during compression is enough to avoid bleeding and at the same time to maintain anterograde flow in the artery.
A prospective study that included patients undergoing diagnostic cardiac catheterization who remained with compressive dressing similar to the one used in this study for two hours revealed that the absent flow before the removal of the compressive dressing was the only independent predictor of RAO at follow-up (18) .
A small portion of patients in our study presented However, a greater occurrence of hematoma was observed after seven days of the procedure in the group that used a compression wristband (p < 0.001), without significant influence on RAO (p = 0.20) (11) .
Authors reported that the radial artery compression time is directly related to the occurrence of RAO. The arbitrary use of recommended times for dedicated devices, which allow patent hemostasis, for customized dressings that hinder the maintenance of anterograde flow may be inadequate, leading to higher RAO. Researchers evaluated the effect of duration of hemostatic compression on the incidence of RAO after transradial coronary intervention and found that patients who maintained compression of the radial artery with a pneumatic wristband for six hours had higher rates of immediate (p = 0.025) and late (p = 0.035) RAO when compared to those who remained with compression for two hours (12) . A randomized study evidenced that compression duration was a strong predictor of RAO, supporting the hypothesis that, in order to minimize radial injury, the compression time should be reduced (19) .
As in our study, authors evaluated the occurrence of hemostasis and vascular complications according to two different times of compression of the radial artery in a randomized study with 568 patients submitted to coronary angiography and percutaneous coronary intervention, and to compression of the radial artery with rotational wristband for 20 or 60 minutes, both with patent hemostasis. The authors identified that patients who remained compressed for 20 minutes and required compression reinforcement showed higher rates of RAO (p < 0.01) and hematoma (p = 0.015).
The need for a further application of pressure in the presence of bleeding in the group that remained for 20 minutes was the only independent predictor of RAO (p = 0.04) (13) .
Authors evaluated the influence of three volumes of insufflation of the wristband that corresponded to the intensity of the compression and time of dwelling on the occurrence of RAO and found that the lower the intensity and the compression time, the lower were the RAO rates (14) .
We decided in the present study to propose a reduction of radial artery compression time before  (20) . It should be noted that the two types of compression were maintained for at least one hour until the first site evaluation. The compression times of this study were higher than the times found in our study, and this may be justified by the fact that our patients were submitted only to diagnostic procedures that required lower doses of anticoagulants, more conservative antiplatelet therapy, and, in most cases the use of introducer sheaths with smaller caliber 5F, which favor the compatibility between the diameter of the introducer sheath and the radial artery, a factor considered important in the prevention of RAO.
Although there was no statistically significant difference between the compression times proposed in the study with respect to the evaluated outcomes, Although a small proportion of the patients presented patent hemostasis after the positioning of the compressive dressing and presented a rate of immediate RAO of 12.5%, regardless of the study group, the incidence rate of RAO (6.9%) in the evaluation after 30 days of the procedure was close to the rates presented in studies on the same theme that used different devices. In a meta-analysis with more than 31,000 patients, the incidence of RAO assessed within 24 hours after the procedure was 7.7% of the patients and 5.8% in the 30-day evaluation (9) . In our study, even without the use of specific hemostatic devices with higher costs than CCDs made with gauze cushions and adhesive tape, we can consider the late RAO rates found here compatible with other studies, especially in the group that remained with compression for less time.
The fact that the study was conducted in a single site, that only patients undergoing diagnostic procedures were allocated, and the difficulty of blinding since allocated patients and professionals were aware of the time established for the permanence of the compressive dressing at the site of the puncture are factors that represent limitations of this study.

Conclusion
The different compression times, either 30 or 60 minutes, applied on the radial artery after transradial coronary angiography did not significantly influence the occurrence of hemostasis and immediate complications.