Radial versus femoral access in ACS patients undergoing complex PCI is associated with consistent bleeding benefit and no excess of risks

Background: The comparative effectiveness of transradial (TRA) compared with transfemoral (TFA) access in acute coronary syndrome (ACS) patients undergoing complex percutaneous coronary intervention (PCI) remains unclear. Methods: Among 8404 ACS patients in the Minimising Adverse Haemorrhagic Events by Transradial Access Site and Systemic Implementation of AngioX (MATRIX)-Access trial, 5233 underwent noncomplex (TRA: n = 2590; TFA: n = 2643) and 1491 complex (TRA: n = 777; TFA: n = 714) PCI. Co-primary outcomes were major adverse cardiovascular events (MACE, the composite of all-cause mortality, myocardial infarction, or stroke) and the composite of MACE and Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding (net adverse cardiovascular events [NACE]) at 30 days. Results: Rates of 30-day MACE (HR 0.94, 95% CI 0.72-1.22) or NACE (HR 0.89, 95% CI 0.69-1.14) did not significantly differ between groups in the complex PCI group, whereas both primary end points were lower (HR 0.84, 95% CI 0.70-1.00; HR 0.83, 95% CI 0.70-0.98; respectively) with TRA among noncomplex PCI patients, with negative interaction testing (Pint = 0.473 and 0.666, respectively). Access-site BARC type 3 or 5 bleeding was lower with TRA, consistently among complex (HR 0.18, 95% CI 0.05-0.63) and noncomplex (HR 0.41, 95% CI 0.20-0.85) PCI patients, whereas the former group had a greater absolute risk reduction of 1.7% (number needed to treat: 59) owing to their higher absolute risk. Conclusions: Among ACS patients, PCI complexity did not affect the comparative efficacy and safety of TRA vs TFA, whereas the absolute risk reduction of access-site major bleeding was greater with TRA compared with TFA in complex as opposed to noncomplex PCI.