Will bronchial thermoplasty for asthma be more widely used?

I first met Carol* (name and identifying details have been changed) when she came to my clinic after a severe asthma attack had sent her to the intensive care unit.  After a few days, she had been extubated and had acquired a new diagnosis: asthma.  When she saw me in clinic, she felt better than she had when she had come to the hospital, but she continued to complain of shortness of breath and a severe cough.  Over the next several months, we figured out that in addition to asthma, Carol had severe acid reflux (or heartburn).  Her stomach acid came back up her esophagus and into her lungs, causing the cough and contributing to her asthma flares.

We added inhalers, more medications and antacid therapy, and yet, Carol kept coming back to the hospital.  Even when she was on prednisone, a strong medication for asthma that has significant long-term side effects, Carol was still in and out of the emergency room due to her asthma. We checked her breathing tests, which were repeatedly normal the morning after she had been admitted for her asthma attacks, which meant her asthma didn’t seem to be as bad as her symptoms would suggest.  The culprit causing her cough and asthma flares, I thought, was her severe acid reflux.

But, as Carol was still coming to the hospital despite maximal medical therapy, she seemed to be the perfect candidate for a new therapy called bronchial thermoplasty.  It is a procedure that involves delivery of controlled thermal energy to the airways with the goal of disrupting the airway muscles, whose increased size and tone cause and contribute to asthma symptoms.

The procedure is new, and exciting, and in the news, with compelling patient success stories, while clinical trials have been limited.  One year after bronchial thermoplasty, there is an improvement in asthma-related quality of life and a reduction in severe asthma exacerbations (asthma attacks requiring emergency department visits or hospitalization, missed days from school or work).  Patients who had the procedure had a lower chance of needing to go to the Emergency Room for an exacerbation.  But they also were more likely to have asthma exacerbations in the immediate post-procedure period.  This increase is attributable to the irritable, inflamed airways reacting to being zapped with a short-term increase in inflammation and irritability.

But what happens to these airways in the long-term?  We are still figuring it out.  At five years, patients still have the same lower asthma exacerbation rate and do not have obvious evidence of long-term consequences due to the disruption of their airways.  Bronchial thermoplasty, then, is a new treatment for severe asthma: One that slightly decreases the dose of inhalers patients have to take, that seems to improve quality of life and reduce ER visits and hospitalizations at the cost of a slight increase in short-term complications.

While some people with severe asthma would benefit from bronchial thermoplasty, many others with severe asthma may gain as much or more benefit by moving out of their moldy apartment, convincing their spouse not to smoke inside the house, re-homing their cat, or simply using their asthma medications more consistently, which, in turn, may be made easier if they could afford them.

So what should we do? Who should get this therapy?  No one really knows.  Some people benefit, yet the data are very limited and we still don’t know what happens ten, or twenty, or more years down the road.  Do all the people who meet the criteria for entry into the clinical trials benefit from the procedure, or could we target this expensive, new procedure to only those few who would be most likely to benefit?

Interventions in medicine are a moving target.  Take any study of any intervention, and if the study evaluates a current therapy or method, it is too short-term.  For most diseases, relatively few people die or get sick during a short time period, so we make guesses at things that may lead to dying.  It is too long and too expensive to show that a drug prevents heart attacks, but showing that a drug lowers “bad” cholesterol or raises “good” cholesterol is much faster, even if the desired cholesterol changes do not always end up translating into the anticipated long-term benefits.  Perform a large, long-term study with important outcomes, and by the time the results get published, the technology and standard of care will have moved so far, that many will consider your study irrelevant to current practice.

Recently, the American Thoracic Society and the European Respiratory Society published their official statement on the treatment and diagnosis of severe asthma.  When it comes to bronchial thermoplasty, they made a strong recommendation based on weak evidence that bronchial thermoplasty be performed in adults with severe asthma “only in the context of an … approved …. registry or clinical study.”

“This recommendation risks stopping bronchial thermoplasty from being performed broadly,” a pulmonologist argued at a conference last year when the expert panel announced their plans to make this recommendation.  ”If we were cardiologists, we would be doing it much more already,” he added, and given the explosion of cardiac catheterization prior to adequate data to determine who would and would not benefit, he may well have been right.  But the world is changing. Doing the new procedure, then figuring out whom it benefits, well after the money has been spent and the patients possibly harmed, no longer appears to be the only path physicians can take on the road to innovation.

It might seem small, but it is a reflection of a great change in medicine.  Rather than simply stating that the evidence is insufficient to recommend for or against an intervention, they issued a guideline strongly advocating for, above all, better evidence on which to base their recommendations.  Increasingly physicians, patients and payers, whoever they may turn out to be, will  demand better information before committing our nation’s resources to the next new thing.  Rather than accept FDA approval and encourage individual doctors to do the best they can for their patients despite the uncertainty, physicians have demanded better information on which we, and our patients, may make decisions.

Yes, we may still have bronchial thermoplasty if our doctors believe it indicated, but ideally as part of a rigorous process that allows us, and society, to better understand whether the procedure has helped us or hurt us, and why.

Denitza Blagev is a pulmonary physician who blogs at mybetterdoctor.

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