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Bronchial Thermoplasty for Patients with Severe Asthma

Regaining Control: Bronchial Thermoplasty Offers New Treatment Option for Patients With Severe Asthma

Asthma, particularly severe asthma, represents a serious economic burden. It overtaxes available health care resources and reduces economic productivity through asthma-related absenteeism, while exacting a heavy toll on patients, dramatically diminishing their quality of life.

FIGURE 1. Airway of person without asthma (top), person with severe asthma (middle) and person with severe asthma after treatment with bronchial thermoplasty (BT).

FIGURE 1. Airway of person without asthma (top), person with severe asthma (middle) and person with severe asthma after treatment with bronchial thermoplasty (BT).

Although those with severe asthma represent only 10% of the 20 million people with asthma in the United States, they account for the majority of health care costs. The average cost per asthma patient is estimated to be $3300. By comparison, a recent study found that yearly costs for study patients with moderate to severe asthma was $5011 but ballooned to $9223 in patients with moderate to severe asthma who experienced an exacerbation.¹

Patients with severe asthma live in fear of their next attack. They must be constantly vigilant, looking for possible triggers that can set off an exacerbation and send them to the emergency room. At any moment, their lives can come undone, and there is little they can do about it. For some, even the most dedicated adherence to the front-line medications for asthma, a combination regimen of long-lasting inhaled corticosteroids and long-acting ß2 agonists, fails to offer symptom relief.

Gerard Silvestri, M.D. (pictured above), Professor of Medicine in the Division of Pulmonary and Critical Care Medicine and Director of Bronchoscopy at the Medical University of South Carolina, was the first pulmonologist in the state to offer patients with medication-refractory severe asthma a new treatment option—bronchial thermoplasty.

Bronchial thermoplasty using the Alair® system (Boston Scientific, Natick, MA), which was approved by the US Food and Drug Administration in 2010 in select patients with severe asthma whose symptoms are not controlled by medications, attempts to achieve symptom control by reducing, through controlled bursts of thermal energy, the smooth muscle mass that tends to build up and become hyperresponsive in patients with severe asthma (Figure 1). During bronchial thermoplasty, a catheter with an expandable electrode array is advanced into the airway via a bronchoscope. When expanded, the electrode array sits snugly in the airway (Figure 2) and can deliver a 10-second burst of radiofrequency energy that is carefully calibrated to reduce the mass of smooth tissue in the airway without affecting surrounding tissue. The electrode array is then repositioned by 5 mm and the next section of airway treated. Care is taken not to treat the same area twice.

Treatment is administered over three sessions, with each of the lower lobes of the bronchi treated in the first two sessions and the top of both bronchi treated in the third.

The Asthma Intervention Research 2 (AIR-2) trial, which randomized patients to either bronchial thermoplasty or to a sham therapy, showed substantial improvements in secondary outcomes for those treated with bronchial thermoplasty, prompting speedy approval of the Alair system by the US Food and  Drug Administration even though the study’s primary end points were not met.² The AIR-2 trial showed a statistically significant improvement in the score on the Asthma Quality of Life Questionnaire in patients receiving bronchial thermoplasty (1.35±1.10 vs 1.16±1.23 for the sham group), one of its primary end points, but the difference did not meet the threshold for clinical relevance (≥.5 points). No differences between the two groups were noted in morning peak flow, rescue medication use or forced expiratory volume (FEV₁). However, impressive gains were noted in the posttreatment period (6–52 weeks) for secondary end points, including a 32% reduction in severe exacerbations (ie, those that required systemic corticosteroids or doubling of the dose of inhaled corticosteroids), significantly fewer visits to the emergency room, and fewer days absent from work (1.32±0.36 days/year vs. 3.92±1.55 days/year).

FIGURE 2. During bronchial thermoplasty, an electrode array provides controlled bursts of thermal energy to smooth muscle in the airway.
FIGURE 2. During bronchial thermoplasty, an electrode array provides controlled bursts of thermal energy to smooth muscle in the airway.

For patients who have lived in fear that sudden severe attacks could send them to the emergency room again and again or jeopardize their jobs, these results are good news indeed. According to Dr. Silvestri, “Early results have shown that bronchial thermo- plasty can make a life-changing improvement in the symptoms

of patients with severe asthma.” Also good news is the assignment of two category 1 CPT codes to bronchial thermoplasty in the recently published CPT 2013 Professional Edition, meaning that providers will be able to seek reimbursement beginning in January 2013 from both private and public payers.

Because bronchial thermoplasty is reserved for patients with severe asthma and because it requires three separate bronchoscopies, it should be performed by a pulmonologist who is skilled in bronchoscopy at a site, like MUSC, with a high volume of bronchoscopy cases.

Patients may experience some increased airway inflammation in the first few weeks after the procedure, but these should resolve in time. The procedure has been shown to be safe at five years, and the durability of its effect has been demonstrated to two years.³

It should be noted that patients with the most severe asthma (one-year history of ≥3 hospitalizations for asthma exacerbations, ≥3 lower respiratory infections, or ≥4 courses of oral steroids) were excluded from the study, putting the generalizability of its findings to the severe asthma population as a whole into question.³ The baseline FEV₁, the amount of air that could be exhaled in one second, of the included patients was also higher (77.8–79.7%) than that used by the National Asthma Education and Prevention Program guidelines to classify patients as having severe asthma (<60%), suggesting that the included patients may have had better breathing function than would be expected for patients with severe asthma, an important point to consider for physicians referring patients for the procedure.

If, as results suggest, bronchial thermoplasty leads to fewer days of work missed and fewer emergency room visits by patients with severe asthma, then it could help reduce the economic and health care burden of the disease. Although bronchial thermoplasty is not a cure for severe asthma, it can render it more moderate and more manageable in select patients. For those patients, it can be transfor- mative, allowing them to regain a sense of control over their once unpredictable lives.

References

¹ Ivanova JI, Bergman R, Birnbaum HG, et al. Effect of asthma exacerbations on health care costs among asthmatic patients with moderate and severe persistent asthma. J Allergy Clin Immunol. 2012;129:1229-35.

² Castro C, Rubin AS, Laviolette M, et al, for the AIR-2 Trial Study Group. Effectiveness and safety of bronchial thermoplasty in the treatment of severe asthma. Am J Respir Crit Care Med. 2010;181:116-124. Available at dx.doi. org/10.1164/rccm.200903-0354OC.

³ Wahidi MM, Kraft M. Bronchial thermoplasty for severe asthma. Am J Respir Crit Care Med. 2012; 185(7):709-714. Available at dx.doi.org/10.1164/ rccm.201105-0883CI

This article originally appeared in the January/February 2013 issue of Progressnotes.

View Highlights

Dr. Gerard Silvestri discusses bronchial thermoplasty in this video interview



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