Despite a relatively low response rate to acid suppression therapy to treat chronic cough, heartburn was a highly significant predictor of success.
Heartburn is a useful predictor of the success of acid suppression therapy in patients with chronic cough, a study published in Lung found.
The sensitivity of using heartburn to detect response to acid suppression was 36.4% and the specificity was 80.4%.
Gastro-oesophageal reflux disease (GORD) is a common condition where stomach acid moves into the oesophagus. It is usually a result of a weakened ring of muscle at the bottom of the oesophagus and can cause symptoms such as heartburn.
GORD is thought to play an important role in chronic cough and patients with the condition are often treated with acid suppression therapy. However, treating atypical GORD symptoms, like cough, can cost 5.6 times more than the cost of treating typical GORD symptoms.
"Thus being able to select which chronic cough patients are more likely to respond to acid suppression is vital, in order to prevent excessive waste of resources and unnecessary risks associated with prolonged drug treatment for the patient," the authors explained.
This study investigated the response rate to acid suppression treatment in patients with and without heartburn.
The researchers performed a retrospective review of 558 patients referred to 2 specialist cough clinics in the United States and United Kingdom (Mayo Clinic and Wythenshawe Hospital, Manchester University Foundation Trust, respectively). The total number of participants was reduced to 320 after excluding those with missing data or chronic cough lasting less than 8 weeks.
The participants were predominantly female (76%), with a mean (SD) age of 61 years (13) and a chronic cough lasting 36 (18-117) months. Almost all participants (96.8%) were non-smokers. The patients were treated with acid suppression and their response to treatment was documented and collected.
Seventy-two patients had heartburn and 20 (28%) noted improvement in their cough with acid suppression. Of the 248 without heartburn, only 35 (14%) responded to the therapy. In the pooled cohort, only 17% (55/320) of patients reported a positive response to acid suppression therapy with no significant difference in success between clinics.
The authors noted that, although there was a low response rate of chronic cough to acid suppression therapy, heartburn was a highly significant predictor of success.
“Our findings indicate that heartburn is the only significant predictor of success of acid suppression therapy when treating chronic cough in a ‘real-life’ setting,” the authors said. “However, it must be acknowledged that only just over a third of those with heartburn gained benefit.”
Patients who reported heartburn were 2.7 times (95% CI, 1.3-5.6) more likely to respond to acid suppression therapy compared with those who did not report heartburn (P = .007). Factors such as age, sex, and lung function did not have a significant effect on the likelihood of success of acid suppression.
“It is worth noting, however, that the vast proportion of patients with chronic cough with concomitant heartburn that responds to acid suppression are probably managed in the community and thus are far less likely to present to specialist clinics,” the authors wrote. “Another possible explanation for the low numbers of responders to acid suppression is that these therapies only suppress the acidity of the refluxate and have no effect on non-acid reflux or the number of reflux events.”
Because the review was retrospective and observational, the authors also mentioned the findings should be interpreted with some caution.
“Although this is consistent with previous retrospective analysis of clinical trial data, our analysis reveals that the overall proportion of patients with chronic cough responding acid suppression is low in a specialist cough setting,” they said. “The majority of these patients’ cough was resistant to therapy.”
Badri H, Satia I, Bansal V, et al. Heartburn as a marker of the success of acid suppression therapy in chronic cough. Lung. Published online November 19, 2021. doi:10.1007/s00408-021-00496-w