Radial PCI and the obesity paradox: Insights from Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2).
OBJECTIVE
To examine if transradial approach (TRA) negates the increased risk associated with femoral access in lean and morbidly obese patients undergoing percutaneous coronary intervention (PCI).


BACKGROUND
Patients at extremes of body mass are at increased risk of bleeding after PCI. TRA has been associated with lower overall rates of bleeding compared to femoral approach.


METHODS AND RESULTS
We studied patients undergoing emergent and elective PCI from 2010 to 2012 across 47 hospitals in Michigan who participate in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium PCI registry. The primary outcomes were the incidences of bleeding and postprocedure transfusion. Propensity matching (PM) was used to adjust for nonrandomized use of TRA. TRA was used in 10,235 procedures. In PM analyses, use of TRA was associated with a reduction in bleeding (0.80 vs. 1.9%, odds ratio [OR] = 0.41, 95% confidence interval [CI] = 0.32-0.54, P < 0.001) and need for transfusion (1.4 vs. 2.5%, OR = 0.56, 95% CI = 0.45-0.69, P < 0.001) compared with femoral access. The absolute difference in bleeding and transfusion associated with TRA was largest in patients with lean body mass (BMI < 25 kg/m(2)) and morbid obesity (BMI ≥ 40 kg/m(2)): Lean patients undergoing TRA had a rate of bleeding of 1.2 versus 2.8% for femoral access (OR = 0.43, 95% CI = 0.24-0.77, P = 0.002); and rate of transfusion of 2.4 versus 3.9% (OR = 0.61, 95% CI = 0.40-0.94, P = 0.019). The morbidly obese had a rate of bleeding of 0.8% for TRA versus 2.4% for femoral access (OR = 0.33, 95% CI = 0.44-0.72, P = 0.004); and rate of transfusion of 1.7 versus 3.0%, (OR = 0.55, 95% CI = 0.30-1.0, P = 0.051).


CONCLUSIONS
Compared with the femoral approach, TRA is associated with a reduction in bleeding across all patients undergoing PCI and the absolute benefit was greatest in those with extremely low or high BMI.