| In the past decades, transradial intervention(TRI) has been widely used as a major access in percutaneous coronary intervention(PCI). Radial approach for coronary angiography was introduced in 1989 by Campeau. In 1992, Kiemeneij performed the first coronary angioplasty via transradial artery approach. In 1993, Kiemeneij performed the first PCI through this route, which brought about the revolution of TRI. The principle of current PCI is achiving the most clinical benefits with the least injury. TRI also helps to reduce bleeding risk, patient hospitalization and the rates of death, which increases patients’ safety. TRI is gaining popularity as a vascular access for PCI in recent years. According to Chinese data, among patients undergoing CAG, more than 89.4% of patients were performed via radial approach in 2015. Several trials, such as RIVAL、RIFLE、REAL and STEMI-RADIAL, have shown that, for people with ST-segment elevation myocardial infarction(STEMI) undergoing primary percutaneous coronary intervention(p PCI), TRI could reduce the rate of bleeding complication and death. Through transradial access, the operatos can decrease the occurrence of bleeding complications and MACEs(major adverse cardiovascular events) without affecting the effects of anticoagulant and antithrombotic therapy, which is a significant advantage and lays the foundation for the improvement of PCI.There were sufficient data confirming the advantages of transforarm intervention. However, small diameters and intraarterial manipulation may result in vascular endothelial dysfunction, extensive damage and occlusion. Despite pretreatment with heparinization, radial artery occlusion(RAO) occured in 5-30.5% of patients after TRI and ulnar artery occlusion(UAO) accounted for 0.8-10.4%. Although TRI is considered a safe and effective option for coronary artery intervention, RAO was an important complication. In spite of the fact that RAO tend to be asymptomatic, it limited using RA as an access site in the future. Reducing vascular endothelial dysfunction, damage and occlusion is of great clinical significance, therefore, RAO deserves operators’ particular attention.So far, several approaches have been proposed to reduce the risk of RAO, including anticoagulation, immediate postprocedural sheath removal, and a small sheath/radial artery ratio. Doppler ultrasound examination showed that interrupted blood flow in RA tend to occur in the proximal end rather than distal part of the artery,which was ignored by a majority of interventional cardiologists. Different insights into occlusion location may lead to different options of sheath materials, models, catheters and puncture access. Thus, we designed this present study to explore the reason of radial artery endothelial dysfuction and damage and occlusion location by flow-mediated dilation(FMD) and OCT, to determine the suitable method to reduce occlusion risk during TRI.The study consists of four parts: the first part is investigating the risk of chronic RAO, exploring whether the interrupted blood flow tend to occur in the proximal RA. part II and III, regarding vascular function study, exploring nifedipine as a preventive application and its protective effects of vascular FMD. The fourth part is evaluating the vascular internal structure by OCT. Part one Influence of puncture site on radial artery occlusion after transradial coronary interventionObjective: The aim of this study was to determine the appropriate puncture site during TRI through comparing the occurrence of RAO between the different puncture sites to reduce the occurrence of RAO after TRI.Methods: We prospectively assessed the occurrence of RAO in 606 consecutive patients undergoing TRI. Artery occlusion was evaluated with Doppler ultrasound in 2 days and 1 year after the intervention. The risk factors of RAO included sex, body mass index(BMI), smoking, hypertension, diabetes, dyslipidemia, puncture site, spasms, and diameter/sheath ratio were evaluated using a multivariate model analysis..Results: Of the 606 patients, the RAO occurred in 56 patients. Compared with TRI at 2–5 cm away from the radius styloid process, the odds ratio(OR) for occlusion risk at 0 cm and 1 cm were 9.65(P = 0.033) and 8.90(P = 0.040), respectively. The RAO occurred in the ratio of the arterial diameter to the sheath diameter ≤1(OR = 2.45, P = 0.004).Conclusions:Distal puncture sites(0–1 cm away from the radius styloid process) can lead to a higher rate of RAO. Part two Effects of nifedipine on structure and function of radial arteryObjective: To investigate whether preventively administration of nifedipine can change the compliance of vascular.Methods: Eligible patients were 60 cases preventively administration of nifedipine 1 day pre-operation. The basal status of blood pressure, heart rate, diameter, resistance index, systole peak velocity were measured at time of 5 minutes, 15 minutes and 30 minutes after administration of nifedipine using ultrasound.Results: A total of 60 patients enrolled in this study from June 2014 to September 2014. At 5 minutes, 15 minutes and 30 minutes, nifedipine did not change mean artery pressure(MAP) and heart rate compared with the baseline.At 5 minutes, nifedipine can be yield the earliest and greatest effect to RA diameter(2.85±0.21 mm vs 2.73±0.21 mm, P=0.002). When diameter <2.73 mm, the diameter increased significantly compared with baseline diameter. At 5 minutes, nifedipine can be yield the earliest and greatest effect to RA systole peak velocity(56.7±7.9cm/s vs 48.7±9.4cm/s, P<0.001). At 5 minutes, RI was significantly decreased compared with the baseline RI(0.77±0.09 vs 0.82±0.06, P<0.001).Conclusions:1 Nifedipine had little effect on blood pressure and heart rate.2 At 5 minutes, nifedipine can be yield the earliest and greatest effect to RA diameter. Part three Effects of nifedipine on endothelium dependent flow-mediated vasodilation after transradial sheath insertionObjective: The aim of this study was to investigate the effect of transradial coronary intervention on vascular function flow-mediated vasodilation(FMD) and evaluate the effect of nifedipine on FMD.Methods: All patients who underwent TRI were randomly assigned to the nifedipine group or the control group if they were not excluded. If patient was allocated to the nifedipine group, sublingual nifedipine(10 mg) was administered immediately 5 minutes pre-TRI. Repeat diameter measurements were recorded for both arms at baseline, 24 h and 48 h to assess FMD. In addition, comparison of endothelin(ET) and nitric oxide(NO) levels of pre-TRI and post-TRI.Results: A total of 120 patents were randomized to nifedipine group or the control group from March 2014 to October 2014. There were no significant differences included sex, body mass index(BMI), risk factors, lesion degree and medicine between two groups. Radial artery spasms were recorded in 16 patients, whereas there were 11 patients occurred RA spasm, control group tended to be spasm, but this tendency did not achieve statistical significance(8.3% vs 18.3, P=0.18).In the cannulated RA of control group, baseline FMD was 12.2±1.5%, FMD was significantly decreased in the RA at 24h(6.4±0.8% vs 12.5±1.7%,P<0.001). At 48 h, RA FMD was also significantly decreased compared with baseline(7.1±0.6% vs 12.2±1.5%,P<0.001). However, in the cannulated RA of nifedipine group, RA FMD was still significantly decreased at 24 h and 48h(7.2±0.9% vs 12.2±1.5%,P<0.001 and 7.1±0.6% vs 12.2±1.5%, P<0.001), whereas the RA FMD of nifedipine group was recovered significantly than control group at 24 h and 48 h. In the cannulated arm, the FMD of brachial artery(BA) was significantly decreased at 24 h between nifedipine group and control group(3.5±0.2% vs 4.7±0.5%,P<0.001 and 3.6±0.3% vs 4.7±0.5%,P<0.001). Overall, BA FMD remained impaired at 48 h between nifedipine group and control group(3.3±0.2% vs 4.8±0.6%, P<0.001 and 3.5±0.4% vs 4.8±0.6%, P<0.001). BA FMD was not recovered after administration of nifedipine. In the noncannulated RA, there was no difference in RA FMD in the two groups during the study.Compared with pre-TRI, the ET level of nifedipine group and control group were higher than the baseline level at post-TRI(13.8±1.0 vs 13.2±1.1,P<0.001 and 14.3±1.3 vs 13.3±1.2,P<0.001). But ET level was recovered after administration of nifedipine(13.8±1.0 vs 14.3±1.3,P=0.02). There was no difference in NO level at pre-TRI and post-TRI between the two groups.Conclusions:1 TRI not only lead to dysfunction of the RA but also impaired the BA.2 Nifedipine can improved the FMD of RA. Part four Assessment of radial artery structure after first and repeated transradial intervention by optical coherence tomographyObjective: We sought to assess the nature of acute and chronic structure change of radial artery after transradial intervention(TRI) using optical coherence tomography(OCT).Methods: From September 2013 to April 2016, 16 patients who underwent coronary OCT imaging, which was used to examine the radial artery after the TRI.Results: This study include the first-TRI(n=12) and repeat-TRI(n=4), The patients’ clinical characteristics of age, sex, body mass index(BMI), smoking, hypertension, diabetes, dyslipidemia, coronary lesion and medicine were no statistic difference. In the distal portion of RA, OCT showed intimal-medial thickness(IMT) were significantly greater in the repeat-TRI than first-TRI(0.37±0.02 mm vs 0.26±0.05 mm, P<0.001), the mean lumen diameter(MLD) and lumen area(LA) were also smaller in repeat-TRI patients than in first-TRI patients. However, VA did not differ between the two groups. In the middle and proximal portion of RA, OCT showed IMT were significantly greater in the repeat-TRI than first-TRI(0.31±0.04 mm vs 0.25±0.02 mm, P<0.001; 0.24±0.03 mm vs 0.29±0.05 mm, P=0.03). However, there were no significant differences in MLD, LA and VA between the two groups in any segment in the middle and proximal portion of RA.Conclusions:1 The MLD of the distal RA portion were significant smaller after TRI.2 The IMT were significantly greater in distal, middle and proximal portion of RA in repeat-TRI. |
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