Bronchial thermoplasty effect on ventilation guided by hyperpolarized 129Xe MRI in severe asthma

Aim: We sought to determine if single-session BT guided by hyperpolarized 129Xe MRI can provide similar benefits as standard BT. Methods: Thirty subjects with severe asthma were randomized to a single treatment of the six most involved airways (guided by XeMRI) or standard three-session BT (unguided). Repeat XeMRI was performed 12 weeks after the first and third BT treatments and compared to baseline. The primary outcome was change in Asthma Quality of Life Questionnaire (AQLQ) 12 weeks after one BT for guided and after third BT for unguided with change in ventilation as a secondary outcome. Results: Subjects had severe (FEV1 69±24%predicted, 63% on chronic oral corticosteroids, 43% on omalizumab) and uncontrolled asthma (ACT 9.6±3.6, AQLQ 2.9±0.9). After one BT, the guided group had a greater reduction in the percent of poorly/non-ventilated lung from baseline when compared to unguided (-17.2%, P=0.009) and significantly higher AQLQ (ΔAQLQ guided=0.96±1.3 P=0.006, unguided=0.54±0.8 P=0.064). One guided BT achieved similar reductions in percent poorly/non-ventilated lung compared to standard BT (-4.6%,P=0.44) and ΔAQLQ (guided=0.96±1.30, unguided=1.46±1.64, P=0.201) with fewer asthma-related adverse events (5 AE, 1 SAE vs 23 AE, 7 SAE). Conclusion: Results of this pilot study suggest that similar improvements can be achieved with one BT treatment guided by XeMRI with improved safety compared with conventional BT.