A large body of evidence supports embracing the transradial approach (TRA) in patients with acute coronary syndrome mainly to decrease major bleeding and complications related to vascular access.1,2 This is well reflected in current guidelines from the American Heart Association3 and the European Society of Cardiology / European Association for Cardio-Thoracic Surgery.4 More specifically, several large randomized trials have been published over the last decade demonstrating advantages of the TRA over the transfemoral approach (TFA) in patients with ST-segment elevation myocardial infarction (STEMI).5-7 In an updated meta-analysis of randomized trials,8 the TRA was associated with lower all-cause mortality (risk ratio [RR], 0.71; 95% CI, 0.57–0.88), major bleeding (RR, 0.59; 95% CI, 0.45–0.77), and vascular complications (RR, 0.42; 95% CI, 0.32–0.56) compared with the TFA for primary percutaneous coronary intervention (PCI). However, patients in cardiogenic shock (CS) were largely excluded from these randomized trials, including in the STEMI-RADIAL (ST-Elevation Myocardial Infarction Treated by Radial or Femoral Approach) trial.6

Due to lack of data on TRA in CS, Tokarek et al9 performed an observational analysis of TRA as compared with TFA in patients with CS and STEMI. A total of 945 propensity-score matched pairs of patients with STEMI and CS treated with primary PCI were evaluated using data from the Polish National PCI Registry (ORPKI). Transradial approach was associated with a lower periprocedural mortality (89 [9.4%] vs 176 [18.6%]; P = 0.001) and a lower incidence of cardiac arrest (92 [9.7%] vs 152 [16.1%]; P = 0.001). Transfemoral approach was the strongest independent predictor of periprocedural mortality in a multivariable analysis (odds ratio [OR], 2.087; 95% CI, 1.629–2.674; P = 0.001). Surprisingly, there was no difference in bleeding complications between TRA and TFA. Thrombolysis in Myocardial Infarction grade 3 flow after PCI was more frequently observed in the TRA group; however, angiographic core laboratory validation was not performed. Overall, reported bleeding rates were very low.

Although recent studies of TRA as compared with TFA did not demonstrate a significant difference in treatment delays, there were previous concerns that TRA might prolong door-to-balloon times.10,11 Reassuringly, in this study, there was no difference in delays between symptoms onset and first medical contact or coronary angiography between the groups.

This analysis of TFA as compared with TRA in CS is nonrandomized and so is only hypothesis-generating. It is likely that residual confounding does exist despite propensity matching given the absolute difference in mortality. Patients and centers that used TRA in CS are likely different than those that used TFA. However, randomized trials of TRA as compared with TFA access in CS are unlikely to be performed given the body of evidence supporting TRA outside of CS. Another important finding from this study is that high-volume operators have better outcomes in patients with acute myocardial infarction and CS particularly with TRA than lower volume operators.

In conclusion, these data support safety and feasibility of TRA in patients in CS, who often do not have a palpable radial artery. Given the wealth of data, a radial-first approach should be considered in CS.