**5. Historical aspects**

**Study name Year Study design No. of patients Endpoints Comments (other outcomes)**

Kasem et al [17]

6 Interventional Cardiology

ALKK PCI registry [18]

Warren J. c. et al. [19]

Graham et al. [22]

Kołtowski et al [23]

2014 Retrospective study

2015 Prospective

2015 Multicenter

data

2016 Prospective

2016 Prospective

Lee et al. [24] 2016 Prospective

Haq et al. [20] 2015 Retrospective

MATRIX [21] 2015 A

observational study

prospectively collected study

Randomized, multicenter study

randomized study

randomized study

randomized study

**(TRI vs. TFI) Results (TRI vs. TFI) P value**

150 vs. 63 D2B and contrast volume.

2530 vs. 15,270 Complications,

bleeding and mortality 1.8 vs. 5.1%

30 vs. 27 min. *P* <

procedure data insignificant except

8.8 vs. 10.3% *P* = 0.0307

two access points 3060 vs. 3374 EUR was insignificant.

4197 vs. 4207 MACE at 30 days NARC and BARC higher

*P* < 0.001.

2947 patients Door to balloon time

45 vs. 47 Demographic and

D2B.

338 vs. 1553 30‐day major bleeding 3.7 vs. 1.2%

52 vs. 51 The cost between the

336 vs. 1609 procedural success,

complications, mortality and MACE

significant better in TRI group

TRI < TFI.

0.001.

TRI is not associated with prolonged door to balloon time or excess contrast utilization. Also TRI is associated with lower mortality, less need for invasive hemodynamic support and fewer local complications.

TRI group show higher procedural success rate and lower vascular access complications and mortality.

Time to first balloon longer with TRI group than with TFI, but no difference mortality and reinfarction rates between

D2B is longer in TRI group than TFA group (*p* = 0.021).

in TFI than TRI group (*p* = 0.0092, *p* = 0.013) and all‐cause mortality (*p* = 0.045).

30‐day death and reinfarction show no significant

statistically difference between

The indirect costs were lower in the radial group. Introduction of radial access as the default approach in all centers may significantly reduce the overall financial burden from a social perspective.

In octogenarians, TRI was more effective than the TFI approach in PPCI.

TRI and TFI.

*P* two groups (*p* = 0.11, *p* = 0.56). = 0.18 insignificant.

Transradial catheterization was started by using the left radial artery as an access for the procedure. The original description of transradial catheterization was introduced by Lucien Campeau in 1989. Campeau successfully completed a coronary angiography by utilization of left radial artery as an access for the transradial procedure. Campeau prepared the left wrist in hyperextension position to facilitate the puncturing of the radial artery. Campeau completed the procedure by using 18‐gage needle, 5‐Fr sheath, and 5‐Fr catheters [26]. The right radial approach was utilized by Ferdinand Kiemeneij in the first description of tran‐ sradial PCI in 1993. Ferdinand Kiemeneij successfully completed a percutaneous coronary intervention by the utilization of right radial artery as an access for the transradial procedure. Kiemeneij completed the procedure by using 22‐gage access needles, 6‐Fr sheath, and 6‐Fr guiding catheters [27].

Since 1993, the right radial approach became the preferable vascular access by the majority of transradial operators. The disruption of the traditional laboratory setup and the relocation of the operator in the left radial approach to the left side of the patient, on the contrary, the right radial approach is more familiar as the femoral approach in the catheter and equipment manipulation from the right side by both the operator and the support staff. However, the left radial artery access has advantages over the right radial approach in lower incidence of vascular anomalies less than right radial and using the left radial approach mimetic the femoral approach regarding the manipulation of the catheters and support of guiding cath‐ eters. **Table 2** summarizes the differences and similarities between right and left transradial accesses based on the most recent studies [28].


**Table 2.** Comparison between right and left radial access [28].
