Impact on Mortality and Major Bleeding of Radial Versus Femoral Artery Access for Coronary Angiography or Percutaneous Coronary Intervention: a Meta-analysis of Individual Patient Data from Seven Multicenter Randomized Clinical Trials.

BACKGROUND: In some randomized controlled trials (RCTs), transradial (TRA) compared with transfemoral access (TFA) was associated with lower mortality in coronary artery disease patients undergoing invasive management. We analyzed the effects of TRA versus TFA across multicenter RCTs and whether these associations are modified by patient or operator characteristics. METHODS: We performed an individual patient data meta-analysis of multicenter RCTs comparing TRA versus TFA among patients undergoing coronary angiography with or without percutaneous coronary intervention (PCI) (PROSPERO; CRD42018109664). The primary outcome was all-cause mortality and the co-primary outcome was major bleeding at 30 days. The primary analysis was conducted by one-stage mixed-effects models based on the intention-to-treat cohort. The impact of access-site on mortality and major bleeding was further assessed by multivariable analysis. The relationship among access-site, bleeding, and mortality was investigated by natural effect model mediation analysis with multivariable adjustment. RESULTS: A total of 21,600 patients (TRA=10,775 vs. TFA=10,825) from 7 RCTs were included. Median age was 63.9 years, 31.9% were female, 95% presented with acute coronary syndrome (ACS), and 75.2% underwent PCI. All-cause mortality (1.6% vs. 2.1%; HR 0.77, 95% CI 0.63-0.95, p=0.012) and major bleeding (1.5% vs. 2.7%; OR 0.55, 95% CI 0.45- 0.67, p<0.001) were lower with TRA. Subgroup analyses for mortality showed consistent results, except for baseline hemoglobin (pinteraction=0.033), indicating that the benefit of TRA was substantial in patients with significant anemia, while it was not significant in patients with milder or no baseline anemia. After adjustment, TRA remained associated with 24% and 51% relative risk reduction of all-cause mortality and major bleeding. A mediation analysis showed that the benefit of TRA on mortality was only partially driven by major bleeding prevention, and ancillary mechanisms are required to fully explain the causal association. CONCLUSIONS: TRA is associated with lower all-cause mortality and major bleeding at 30 days, compared with TFA. The effect on mortality was driven by patients with anemia. The reduction in major bleeding only partially explains the mortality benefit.