The size ratio between two major arteries, which can be seen on CT scans, can be a reliable indicator that a patient's chronic obstructive pulmonary disease (COPD) will get worse, according to a new study.
Exacerbation of COPD brings decline in lung function, poorer quality of life and often hospitalization, where treatment is expensive--it accounts for $18 billion in direct costs in the United States each year. Those hospitalized face a 21 percent chance of death within one year and that risk rises to 55 percent within five years, according to an announcement.
The study, from the University of Alabama at Birmingham, was published online in the New England Journal of Medicine. Though the aorta normally is a little larger than the pulmonary artery, the pulmonary artery may enlarge in patients with COPD for reasons such as loss of lung tissue or accompanying heart disease.
The research involved 3,464 patients enrolled in the COPD Gene study sponsored by the National Heart, Lung and Blood Institute, and 2005 patients enrolled in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) study sponsored by GlaxoSmithKline. Participants were current or former smokers. A ratio of more than 1 between the pulmonary artery and aorta was found to be a good indicator of exacerbation.
"Our findings indicate that when the pulmonary artery becomes larger than the aorta, regardless of the underlying cause or other health conditions, the risk of exacerbation increases. In particular, the risk of exacerbation requiring hospitalization increases dramatically," writes Dr. Mark Dransfield, associate professor in the UAB Division of Pulmonary, Allergy and Critical Care Medicine.
Since many smokers undergo CT scans anyway, this added knowledge could provide physicians with impetus to more aggressively treat COPD to ward off hospitalization, the authors say.
However, an accompanying editorial warns against a rush to use CT for this purpose alone, citing echocardiography and measurement of arterial blood gases as examples of simpler and more cost-effective methods to determine pulmonary pressure. It calls for much more research.
Indeed, earlier this year the VA canceled a study aimed at reducing COPD-related hospital readmissions amid safety concerns.
And while undertreatment for COPD can turn deadly, overtreatment can raise risks as well and be unnecessarily costly, as FierceHealthcare has reported.
Meanwhile, though the debate continues over whether smokers should undergo annual CT scans to look for lung cancer, three medical groups in May came out in favor of them for one particular group: current or former heavy smokers aged 55 to 74. The American College of Chest Physicians, the American Society of Clinical Oncology and the National Comprehensive Cancer Network came out in favor of the annual scans for those who smoked at least one pack of cigarettes a day for at least 30 years.
To learn more:
- read the study
- here's the editorial
- check out the announcement