Association of the arterial access site at angioplasty with transfusion and mortality: the M.O.R.T.A.L study (Mortality benefit Of Reduced Transfusion after percutaneous coronary intervention via the Arm or Leg).

Background: Bleeding and transfusion after percutaneous coronary intervention (PCI) are known predictors of mortality. Transradial arterial access reduces bleeding and transfusion related to femoral access complications, although its association with mortality is unknown.

Objective: To determine the association of arterial access site (radial or femoral) with transfusion and mortality in unselected PCIs.

Design, Setting And Patients: By data linkage of three prospectively collated provincial registries, 38,872 procedures in 32,822 patients in British Columbia were analysed. The association between access site, transfusion and outcomes was assessed by logistic regression, propensity score matching and probit regression.

Main Outcome Measures: 30-Day and 1-year mortality.

Results: 1134 (3.5%) patients had at least one blood transfusion. Transfused patients had a significantly increased 30-day and 1-year mortality, adjusted odds ratio (95% CI) 4.01 (3.08 to 5.22) and 3.58 (2.94 to 4.36), respectively. By probit regression the absolute increase in risk of death at 1 year associated with receiving a transfusion was 6.78%. The number needed to treat was 14.74 (prevention of 15 transfusions required to "avoid" one death). Radial access halved the transfusion rate. After adjustment for all variables, radial access was associated with a significant reduction in 30-day and 1-year mortality, odds ratio = 0.71 (95% CI 0.61 to 0.82) and 0.83 (0.71 to 0.98), respectively (all p<0.001).

Conclusions: In a registry of all comers to PCI, transradial access was associated with a halving of the transfusion rate and a reduction in 30-day and 1-year mortality.