Cited 2 times since 2020 (1.2 per year) source: Scopus Respiratory research, Volume 21, Issue 1, 12 2 2020, Pages 52 Resistance of the respiratory system measured with forced oscillation technique (FOT) correlates with bronchial thermoplasty response. Goorsenberg AWM, d'Hooghe JNS, Slats AM, van den Aardweg JG, Annema JT, Bonta PI

Background

Bronchial Thermoplasty (BT) is an endoscopic treatment for severe asthma using radiofrequency energy to target airway remodeling including smooth muscle. The correlation of pulmonary function tests and BT response are largely unknown. Forced Oscillation Technique (FOT) is an effort-independent technique to assess respiratory resistance (Rrs) by using pressure oscillations including small airways.

Aim

To investigate the effect of BT on pulmonary function, assessed by spirometry, bodyplethysmography and FOT and explore associations between pulmonary function parameters and BT treatment response.

Methods

Severe asthma patients recruited to the TASMA trial were analyzed in this observational cohort study. Spirometry, bodyplethysmography and FOT measurements were performed before and 6 months after BT. Asthma questionnaires (AQLQ/ACQ-6) were used to assess treatment response.

Results

Twenty-four patients were analyzed. AQLQ and ACQ improved significantly 6 months after BT (AQLQ 4.15 (±0.96) to 4.90 (±1.14) and ACQ 2.64 (±0.60) to 2.11 (±1.04), p = 0.004 and p = 0.02 respectively). Pulmonary function parameters remained stable. Improvement in FEV1 correlated with AQLQ change (r = 0.45 p = 0.03). Lower respiratory resistance (Rrs) at baseline (both 5 Hz and 19 Hz) significantly correlated to AQLQ improvement (r = - 0.52 and r = - 0.53 respectively, p = 0.01 (both)). Borderline significant correlations with ACQ improvement were found (r = 0.30 p = 0.16 for 5 Hz and r = 0.41 p = 0.05 for 19 Hz).

Conclusion

Pulmonary function remained stable after BT. Improvement in FEV1 correlated with asthma questionnaires improvement including AQLQ. Lower FOT-measured respiratory resistance at baseline was associated with favorable BT response, which might reflect targeting of larger airways with BT.

Trial registration

ClinicalTrials.gov Identifier

NCT02225392; Registered 26 August 2014.

Respir Res. 2020 2;21(1):52