Radiation burden in chronic total occlusion percutaneous coronary intervention is driven more by lesion complexity...

Radiation exposure is an important safety issue in chronic total occlusion percutaneous coronary intervention (CTO PCI). Right coronary artery (RCA) CTO PCI is often associated with a higher radiation burden, but it remains unclear whether this reflects the target-vessel location itself or differences in lesion complexity and strategy selection.

We analyzed 1800 consecutive CTO PCI procedures performed between January 2020 and June 2025 at three participating CTO PCI centers (RCA n = 1013; left anterior descending coronary artery n = 540; left circumflex coronary artery n = 247). High radiation exposure was defined as a dose-area product (DAP) greater than the 90th percentile among available DAP values (>35 400 cGy·cm2). DAP was available in 1321 procedures (73.4%). RCA cases had longer fluoroscopy time and higher median DAP in unadjusted analyses. In the center-adjusted primary model, planned retrograde/hybrid strategy (adjusted odds ratio: 2.23, 95% confidence interval: 1.42-3.51) and higher J-CTO score (adjusted odds ratio: 1.70, 95% confidence interval: 1.39-2.09) were the strongest predictors of high DAP, whereas target vessel was not independently associated with excess radiation after adjustment. A Firth penalized center-adjusted sensitivity analysis yielded the same interpretation. Secondary analyses using continuous DAP and clinically relevant air kerma thresholds supported the same overall pattern.

In CTO PCI, the higher radiation observed in RCA cases was mainly associated with lesion complexity and anticipated retrograde/hybrid strategy rather than with target-vessel location alone. These findings support strategy-based radiation risk assessment and careful donor-vessel protection when retrograde or hybrid crossing is expected.