Study Finds No Benefit in Screening AS Patients for Heart Disease Absent Clinical Symptoms
Both the lifetime risk of valvular heart disease (VHD) and the need for pacemakers markedly increase with age for people with ankylosing spondylitis (AS). But these risk rates are only slightly higher than those for people without the disease, a U.S. population-based study shows.
In light of these findings, the researchers believe there is no relevant benefit from screening people with AS for heart disease, if they have no clinical symptoms.
The study, “Lifetime Risks of Valvular Heart Disease and Pacemaker Use in Patients With Ankylosing Spondylitis,” was published in the Journal of the American Heart Association.
Up to 82% of people with ankylosing spondylitis may have some heart shape abnormality on echocardiography, the researchers found. But most of the abnormalities are subclinical, meaning they cause no symptoms.
The prevalence of VHD, caused by defects in one of the four valves of the heart — the mitral, aortic, tricuspid or pulmonary — is not well-known among this patient population, with a study placing the incidence between 1% and 12%.
The same is true for conduction disorders, or problems with the electrical impulses that travel through the heart, which can lead to an irregular heartbeat. Such disorders have been reported to affect 1% to 35% of people with AS.
Given that the burden of both conditions is ill-defined, scientists questioned whether asymptomatic patients — those without symptoms — should be screened for these heart problems.
To learn more, a team of researchers at the National Institute of Arthritis and Musculoskeletal and Skin Diseases investigated the lifetime risk of clinically relevant valvular heart disease and conduction blocks in individuals with AS.
Patients with AS, ages 65 and older, and a comparison group without AS were identified among U.S. Medicare beneficiaries from 1999 to 2013.
Researchers determined the incidence of valve replacement or valve revision surgeries as a measure of the severity of valvular heart disease. They examined the incidence of pacemaker use as a measure of cardiac conduction or heart rhythm abnormalities.
Four age groups were compared — 65 to 69 years, 70 to 74 years, 75 to 79 years, and 80 years or older — from a total sample of 42,327 patients with AS and 19.2 million controls.
The data revealed that the likelihood of AS patients having aortic valve disease increased with age — 2.6%, 6.7%, 10.9%, and 17.1%, by age group respectively — as did mitral valve disease.
However, when compared with control subjects, the risk of valvular heart disease was only slightly higher in people with AS.
The proportion of AS patients who had aortic valve replacement or repair was also higher than in the comparison group in all four age groups. There was no difference regarding mitral valve surgery between groups.
Similar findings were noted in reviewing the need for pacemakers. Their use among people with AS ranged from 1.0% to 7.6% across age groups, and similarly to valvular heart disease, was slightly higher than in controls.
“A higher than expected prevalence of disease is a prerequisite for the development of targeted screening approaches for a risk group. That the risks of VHD and pacemaker use were only slightly higher among elderly patients with ASp in this population‐based study does not support the development of screening strategies using echocardiography or electrocardiography in asymptomatic patients. These investigations should be reserved for patients with suggestive signs or symptoms,” the researchers concluded.