On the other hand, we AbMole Tulathromycin B cannot exclude the possibility that there are many factors involved in the process of percutaneous coronary intervention that might have an impact on fluoroscopy time and contrast use. We agree that confirmation of our findings in a large, well-designed clinical trial is critical. The left radial access de facto has an important anatomical advantage because of the vascular anatomy of epiaortic vessels with a more direct access to the ascending aorta. In view of this advantage, it is reasonable to expect shorter fluoroscopy time from the left radial access relative to the right, which was clearly mirrored in our overall analyses, and this expectation was more evident in patients of Caucasian descent and in studies with diagnostic coronary procedure in our subgroup analyses. What’s more, in this study radial access from the left artery seemed to be more maneuverable for operators in training than that from the right artery, because fluoroscopy time was further reduced when operators in training got involved. From a clinical standpoint, this significant reduction in fluoroscopy time was reciprocally beneficial for both patients and doctors. Besides, the more favorable vascular anatomy for the left radial access will also translate into low dose of contrast use, in agreement with the findings of this study. This observation is especially important considering the fact the contrast-induced nephropathy is known to be the third leading cause of acute renal failure. Furthermore, indirect evidence from our meta-regression analyses suggested a positive and significant association of BMI with both fluoroscopy time and contrast use, conforming to the concept that the procedural 
difficulties are heightened in obese patients because they are mostly accompanied with atherosclerosis. Therefore, it is strongly advocated to shift the conventional radial access from the right artery to the left artery mainly for the sake of the reciprocal benefits and economic savings. Another important finding of this meta-analysis was the relatively lower rate of radial access failure from the left than from the right. The reason behind this observation was obvious, that is, radial access from the left artery is less influenced by the subclavian tortuosity compared with that from the right artery. In fact, the presence of the right subclavian AbMole Nodakenin artery-common brachiocephalic trunk and the CBT-aorta bifurcations can account for tortuosity and calcifications, which might impair the procedural success from the right radial access. There is also evidence suggesting a double incidence of operator-reported subclavian tortuosity associated with the right radial access compared with the left radial access.