Relationship Between Radial Artery Flow-mediated Dilation And Arterial Spasm During CAG And PCI

Objective: Transradial coronary catheterization has been performed over the last few years. Access site crossover appears to be more frequent when the initial route is the transradial one for reasons of arterial spasm. Flow mediated dilation(FMD) is an established method of studying endothelial function and nitric-oxide-dependent dilation of peripheral arteries. The aim of this study was to explore the relationship between flow mediated dilation(FMD) and radial arterial spasm in coronary angiography(CAG) and percutaneous coronary intervention(PCI) by transradial approach and to investigate whether FMD could be used as a preprocedural method to predict arterial spasm.Methods: Patients who were planned to accept CAG and/or PCI from Jan. 2015 to Mar. 2015 in the Fifth Department of Cardiovascular in Second Hospital of Hebei Medical University were selected. Exclusion criterion:(1) >80 years old;(2) with severe renal failure(creatinine clearance rate <30 ml/min);(3) transulnar approach for CAG or PCI;(4) previous coronary artery bypass graft surgery;(5) forearm deformity, trauma, surgical history;(6) known peripheral vascular disease;(7) failure to successfully cannulate the radial artery;(8) acute myocardial infarction needed emergency operation;(9) with negative Allen’s test. FMD was measured 1 to 2 days before PCI or CAG. All of the cases have received conventional medical treatment before PCI or CAG. The demographics and clinical characteristics were recorded, including age, gender, body mass index(BMI), medical history, smoking, previous radial catherization and medications. The right radial artery cannulation was performed in all cases. 6-Fr hydrophilic sheaths were used conventionally, and 4-Fr or 7-Fr were selected according to the judgement of patients’ condition. 4-Fr catheters were used for diagnostic coronary angiography and 6-Fr or 7-Fr guiding catheters for PCI. Guide wires, balloons, stents and additional devices including intravascular ultrasound, pressure wire, and optical coherence tomography catheter were used freely by the operators, according to their judgment. Operation type, duration of procedure, catheters, number of catheters exchanged, access site crossover, volume of contrast and additional modalities used during the PCI procedure were recorded in detail. Cases were divided into two groups(RA spasm group and No RA spasm group) according to the manifestation of artery spasm during the PCI procedure. Comparative analysis of the basical clinical characteristics(including FMD) and data related to operation were conducted. At the same time, the independent risk factors of radial spasm were analysed. We also analysed the FMD and diameter between radial artery and ulner artery of cases without radial artery cannulation history. All data were analysed with SPSS 20.0 software. Continuous variables were summarized as mean ± standard error of the mean, compared using the t-test, or as median(interquartile range), and compared using the Mann-Whitney U test. Categorical variables were summarized as counts and percentages and compared using the chi-square test of Fisher’ s exact test, if the produced matrices contained cells with expected counts less than five. The independent significance of potential predictors of occurrence of arterial spasm was evaluated using binary logistic regression. Receiver’s operating characteristic(ROC) curve analysis was applied to compute the best discriminating FMD value for the prediction of spasm. P values ≤ 0.05 were considered as statistically significant.Results:1 A total of 140 patients(97 males) were included, with 10 cases in RA spasm group and 130 cases in No RA spasm group. In the univariate analysis, there were no significant diffrences in age, gender, BMI, smoking, diabetes, hypertension, dyslipidemia, previous radial catherization and ulner FMD. In regard to medications, the administration of β receptor-blocker, aspirin, calcium channel blocker, ACEI/ARB, statins, nitrates and P2Y12 receptor antagonists were no significant changes among the cases. As to data related to operation, the PCI percentage, 7-Fr guiding catheters and the additional modalities used showed no statistically significant in our study. Compared with No RA spasm group, RA spasm group showd significant decreased in FMD [3.9%(3.4%~4.8%) vs. 6.8%(5.4%~8.3%), P < 0.001], significant smaller radial artery diameter(2.36 mm vs. 2.63 mm, P = 0.013), and significant longer durations of procedure [48.5min(32.5 min ~ 85.2 min) vs. 25.0 min(16.5 min ~ 40.0 min), P<0.001]. A significant relation was also found between the number of catheters exchanged during PCI and the appearance of spasm [2.5(2.0~3.2) vs. 2.0(1.0~2.0), P = 0.001]. As expected, radial artery spasm was strongly related to the need for access site crossover [4(40%) vs. 3(2.3%), P<0.001], as well as with administration of higher contrast volumes [130.0ml(87.5ml~265.0ml) vs. 70.0ml(50.0ml~160.0ml), P = 0.014].2 In the binary logistic multivariate analysis, radial FMD(OR = 16.7, 95% CI = 1.75~159.10, P = 0.014), radial artery diameter(OR = 9.1, 95%CI = 1.33~62.41, P = 0.025), and the number of catheters exchanged(OR = 8.1, 95%CI = 1.39~47.37, P = 0.020) were important independent risk factors for radial artery spasm and FMD was the most(P<0.05).3 The analysis of the ROC curve for the prediction of spasm based on FMD values showed that area under the curve was 0.859(P<0.001) and a value of 4.5% could be used as a cut-off to predict spasm with a sensitivity of 85.4% and a specificity of 80%.4 There was no significant difference among the cases without previous radial catherization when compared radial artery diameter with ulner artery diameter(radial artery vs. ulner artery: 2.60 mm(2.40 mm~2.89 mm) vs. 2.70 mm [2.50 mm~2.90 mm), P = 0.115]. On the other hand, FMD of radial artery and ulner artery showed a significant difference[radial artery vs. ulner artery: 6.8%(5.3%-8.2%) vs 7.4%(6.3%-8.7%), P = 0.004].Conclusions:1 Radial artery FMD, radial artery diameter and the number of catheters exchanged during PCI were independent risk factors for spasm during transradial coronary procedures.2 Preprocedural FMD measurements could be used in deciding on the vascular access route for an elective procedure and predicting radial spasm with its low cost, safe, and feasible noninvasive characteristics.3 Ulner artery which possessed better diastolic ability and the potential of decreased frequency of spasm was the most pivotal alternative access route for CAG and PCI in addition to the radial artery.