by Phyllis Hanlon, Contributing Writer
Pulmonary hypertension (PH) and chronic obstructive pulmonary disease (COPD) both affect breathing and heart function. They also sometimes occur at the same time. People with COPD often have a small amount of PH, as the pressure in the lungs may increase to accommodate changes in the lungs caused by COPD. However, a diagnosis of COPD and PH can be confusing and difficult to make. Each disease is diagnosed using different methods and they have overlapping symptoms. But determining the correct diagnosis is an important first step that could lead to better treatment options and outcomes, according to a recent study. (https://www.ncbi.nlm.nih.gov/pubmed/?term=28715281)
A team of researchers from the Baylor College of Medicine and the Michael E. DeBakey Veterans Affairs Medicine Center, both in Houston; the University of Texas System in Austin; and the Veterans Health Administration in Washington, D.C., conducted a study that looked at the factors that might predict whether a patient with COPD receiving care in a Veteran’s Affairs Healthcare Network also had a recognized diagnosis of PH.
The study involved 545,086 patients who were treated at the South Central Veteran’s Affairs Healthcare Network (VISN16) between 2000 and 2012. All patients included in the study had either been an inpatient discharged with a primary diagnosis of COPD or who had two outpatient visits with a primary diagnosis of COPD.
The researchers selected the patients based on their ICD-9 code, a billing code used in medicine which identifies the patient’s medical condition. This selection method resulted in the creation of two subgroups: patients diagnosed with both PH and COPD (PH-COPD) (2,176 patients) and those with COPD but no PH diagnosis (51,832 patients). Together, this represents approximately 10% of the VISN16 patients with COPD.
The study authors found some differences between the two groups. The PH-COPD group was slightly older (67.2 years) than the COPD-only group (66.7). Additionally, the PH-COPD group were larger, with a body mass index (BMI) of 29.3 kg/m2 versus 27.6 for the COPD-only group. The PH-COPD group also had more comorbid conditions than the COPD-only group, including obstructive sleep apnea (OSA), and were more likely to be on heart medications, including beta-blockers, statins, and anticoagulation/aspirin.
After reviewing the data, the researchers determined that the frequency with which a person went to the hospital because of a COPD exacerbation was “…a factor in predicting the diagnosis of [both] PH-COPD.” For this study, the researchers defined “exacerbations” as a COPD patient who has two COPD “events” within two weeks of each other. In other words, the more often a patient was admitted to the hospital because of worsened COPD, the more likely it was he or she would also have a diagnosis of PH. Approximately 4 percent of patients diagnosed with COPD have a PH diagnosis, according to the researchers in this study.
Currently, clinicians do not routinely check for PH in a patient with COPD. Right heart catheterization (RHC) is the only way to definitively characterize PH, but is an invasive procedure not routinely done in patients with COPD, the study authors noted. Also, some symptoms, particularly shortness of breath when exercising, can be found in both diseases. The researchers also pointed out that the Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) (https://www.ncbi.nlm.nih.gov/pubmed/26066077) reported that 20 percent of patients with PH also have obstructed airways, which is characteristic of changes also seen in COPD.
This study does have some limitations, the authors noted. For one, using the ICD-9 billing codes (called an “administrative study”) does not always provide accurate results; the codes used for PH at the time the data was collected were very general and might miss some PH diagnoses or might apply a PH diagnosis when the disease is not present. Also, some of the PH diagnoses in this study might have been made based on echocardiograms, which are not always precise, according to the authors.
When it comes to COPD, the ICD-9 codes might include patients with pneumonia. The authors also pointed out that, since they looked at previously recorded data, they do not have reliable information regarding the time between when the patient received the COPD diagnosis and when he was admitted to the hospital for PH and COPD.
Based on the results of this study, the researchers proposed “…that patients with COPD who are hospitalized for an exacerbation should be evaluated for PH and/or the presence of diastolic and/or systolic left heart dysfunction.” They added that it’s important to correctly diagnose a patient so specific therapies that target PH can be started.
Lavannya M. Pandit, MD, one of the study authors, added that veterans are an at-risk population for developing PH. “…Early screening in this population is particularly important in improving survival and decreasing health care costs associated with advanced heart lung disease, risk factors for developing PH,” she said. Dr. Pandit went on to indicate that identifying clinical risk factors, such as frequent hospitalization and other comorbid conditions could allow for more effective screening for PH and appropriate use of right heart catheterization as an invasive, gold-standard PH diagnostic test.
Each PH patient is different. It is essential that you talk to your own doctor about what treatment options are best for you. For more information on finding a doctor or an accredited care center, visit https://www.phassociation.org/PHCareCenters/Patients.