Aims: Interventional cardiologists are exposed to substantial occupational ionising radiation. This study sought to investigate differences in radiation exposure in biplane versus monoplane coronary angiography and percutaneous coronary interventions (PCI).
Methods and results: RAMBO (RAdiation exposure in Monoplane versus Biplane cOronary angiography and interventions) was a prospective, randomised, two-arm, single-centre, open-label trial, enrolling a total of 430 patients undergoing coronary angiography. Patients were randomly assigned to biplane or monoplane imaging. The primary efficacy measure, the operator radiation dose at the level of the left arm as measured by a wearable electronic dosimeter, was significantly higher in the biplane as compared to the monoplane group (4 [1-13] µSv vs 2 [0-6.8] µSv, p<0.001). The dose area product was 11,955 (7,095-18,246) mGy*cm2 and 8,349 (5,851-14,159) mGy*cm2 in the biplane and the monoplane groups, respectively (p<0.001). While fluoroscopy time did not differ between the groups (p=0.89), the amount of contrast medium was lower with biplane as compared with monoplane imaging (p<0.001).
Conclusions: Biplane imaging for coronary angiography and PCI is related to an increased radiation exposure for the interventional cardiologist as compared with monoplane imaging. Monoplane imaging should be considered for advanced radioprotection in cardiac catheterisation, with biplane imaging used for selected cases only.