Procedural and short-term safety of bronchial thermoplasty in clinical practice: evidence from a national registry and Hospital Episode Statistics

ABSTRACT

Objective: Bronchial thermoplasty (BT) is a novel treatment for severe asthma. Its mode of action and ideal target patient group remain poorly defined, though clinical trials provided some evidence on efficacy and safety. This study presents procedural and short-term safety evidence from routine UK clinical practice. Methods: Patient characteristics and safety outcomes (procedural complications, 30-day readmission and accident and emergency (A&E) attendance, length of stay) were assessed using two independent data sources, the British Thoracic Society UK Difficult Asthma Registry (DAR) and Hospital Episodes Statistics (HES) database. A matched cohort (with records in both) was used to estimate safety outcome event rates and compare them with clinical trials. Results: Between June 2011 and January 2015, 215 procedure records (83 patients; 68 treated in England) were available from DAR and 203 (85 patients) from HES. 152 procedures matched (59 patients; 6 centres), and of these, 11.2% reported a procedural complication, 11.8% resulted in emergency respiratory readmission, 0.7% in respiratory A&E attendance within 30 days (20.4% had at least one event) and 46.1% involved a post-procedure stay. Compared with published clinical trials which found lower hospitalisation rates, BT patients in routine clinical practice were, on average, older, had worse baseline lung function and asthma quality of life. Conclusions: A higher proportion of patients experienced adverse events compared with clinical trials. The greater severity of disease amongst patients treated in clinical practice may explain the observed rate of post-procedural stay and readmission. Study of long-term safety and efficacy requires continuing data collection.

KEYWORDS:

• Airway smooth muscle
• clinical registry
• interventional procedure
• observational data
• routine administrative data
• severe asthma

Acknowledgements

We are grateful for the support of medical staff at centres performing bronchial thermoplasty including A. Menzies-Gow, N. C. Thomson, R. Chaudhuri, B. Higgins, A. H. Mansur, C. E. Brightling, P. H. Howarth, R. Angus, J. Blakey, K. S. Babu and P. Sivasothy. Also to nursing and data input staff at each centre who have assisted with data entry; Royal Brompton Hospital (London), University Hospital of South Manchester, Gartnavel General Hospital (Glasgow), Freeman Hospital (Newcastle upon Tyne), Birmingham Heartlands Hospital, University Hospitals of Leicester, University Hospital Southampton, Aintree University Hospital (Liverpool), Queen Alexandra Hospital (Portsmouth) and Addenbrooke's Hospital (Cambridge). HES data held by the UK NHS Health and Social Care Information Centre have been used to help complete the analysis (©2015. Reused with the permission of the Health and Social Care Information Centre. All rights reserved).

Declaration of interest

LGH has received grant funding from Medimmune, Novartis UK, Roche/Genentech Inc, AstraZeneca and GlaxoSmithKline, have taken part in advisory boards and given lectures at meetings supported by GlaxoSmithKline, Respivert, Merck Sharp & Dohme, Nycomed, Boehringer Ingelheim, Novartis and AstraZeneca. LGH has received support funding to attend international respiratory meetings (AstraZeneca, Chiesi, Novartis, Boehringer Ingelheim and GlaxoSmithKline) and has taken part in asthma clinical trials (GlaxoSmithKline, Schering-Plough, Synairgen and Roche/Genentech) for which his institution was remunerated. LGH is Academic Lead for the Medical Research Council Stratified Medicine UK Consortium in Severe Asthma which involves industrial partnerships with Amgen, Johnson & Johnson, Genentech/Roche, AstraZeneca/Medimmune, Aerocrine and Vitalograph. RN was PI (principal investigator) on several of the thermoplasty trials, and has received honoraria for lecturing and attending advisory boards from Boston Scientific.

Funding

Pilot funding for the Difficult Asthma Registry was provided as unrestricted research grants from AstraZeneca, GlaxoSmithKline, Novartis and Medimmune. The extension of the Difficult Asthma Registry to include bronchial thermoplasty data collection was funded by NICE. JB, AJS and KK are employed by The Newcastle upon Tyne Hospitals NHS Foundation Trust which hosts an External Assessment Centre funded by NICE.