COPD Patients Have a Higher Risk of Heart Disease, Study Shows
People with chronic obstructive pulmonary disease (COPD) have a higher risk of developing heart disease, even if they only have mild lung function impairments, a study suggests.
Also, being male, older, and using statins — a group of medicines commonly prescribed to lower cholesterol levels in the blood — were all found to be associated with a higher risk of heart disease.
The findings support the need to be vigilant about heart conditions for all COPD patients.
“This study shows the importance of early detection of coronary heart disease among COPD patients, especially considering the overlapping symptoms,” Christina D. Svendsen, the study’s first author from Haukeland University Hospital in Bergen, Norway, said in a press release.
The study, “Factors associated with coronary heart disease in COPD patients and controls,” was published in PLOS One.
COPD patients often develop coronary heart disease (CHD), a condition in which the blood vessels that normally supply blood to the heart become blocked by fatty substances. However, direct evidence that COPD itself can lead to CHD is scarce, as are the potential risk factors that link COPD to heart disease.
Researchers at Haukeland University Hospital investigated whether COPD patients have a higher risk of developing CHD compared with those without the disease by comparing their results on a CT angiography scan and on a pulmonary CT.
A CT angiography scan combines CT imaging with a special dye that’s injected to visualize the arteries that supply blood to the heart. The heart CT scan can also be used to determine the heart’s calcium-score (CaSc), which reflects the amount of calcium deposits found in the walls of the heart’s arteries. A higher CaSc indicates an increased risk of a future heart attack. A CaSc above 100 was used in this study as an indicator of a high risk for CHD.
Additional parameters analyzed included the presence of emphysema — a severe form of COPD — the frequency of disease worsening episodes (exacerbations), and hypoxemia (low blood oxygen levels).
In total, researchers analyzed data from 347 COPD patients (mean age, 69 years) and 428 people without COPD (mean age, 64.8 years), who served as controls. Participants were recruited from two previous studies: the Bergen COPD Microbiome (MicroCOPD) study and the follow-up GeneCOPD study. The MicroCOPD study was designed to compare the composition of microbes living in the airways of people with and without COPD, as well as to study the possible interactions between these microbes and the host’s immune system.
Among COPD patients, 12.6% had coronary stenosis — a condition wherein the heart’s coronary arteries become narrower. This only was seen in 5.7% of individuals without COPD.
Also, a significantly higher fraction of COPD patients was at higher risk of heart disease — had a CaSc score above 100 — compared with controls (55.9% vs. 31.6%). A statistical analysis also indicated that COPD patients had a 1.68-times higher risk of developing heart disease compared with people without COPD. Being male, older, and using statins were all significantly associated with a CaSc above 100, after adjusting for several confounding parameters.
Overall, these findings support an “added risk for CHD among COPD patients,” the researchers wrote. This increased risk was present even in patients with mild lung function impairment, supporting the need for vigilance for heart disease for all COPD patients.