Necessary to establish baselines, ensure patient safety
by Wayne Kuznar , Contributing Writer
Note that this cohort study of patients with lupus, ankylosing spondylitis, and rheumatoid arthritis found a significantly higher rate of exercise test abnormalities compared with healthy, sedentary controls.
These abnormalities persisted after adjustment for confounders such as smoking, hypertension, and diabetes.
An abnormal exercise test is more common in patients with asymptomatic cardiovascular systemic inflammatory rheumatic disease compared with healthy sedentary controls.
In a cross-sectional study of patients with systemic inflammatory rheumatic diseases, the likelihood of a positive exercise test was increased by up to 14 times after controlling for age, body mass index (BMI), smoking, hypertension, diabetes mellitus, and dyslipidemia, found Bárbara Nascimento de Carvalho Klemz, MD, from the Federal University of Sao Paulo, Brazil, and co-investigators.
The findings “reinforce the need to perform exercise tests before prescribing supervised physical exercise programs in order to identify possible changes induced by effort in patients with subclinical cardiovascular disease as well as to ensure the safety of this intervention,” they wrote online in Rheumatology.
On logistic regression analysis, the likelihood of a positive exercise test was increased significantly in patients with lupus (OR 13.75, 95% CI 2.92-64.78), rheumatoid arthritis (RA) (OR 13.56, 95% CI 6.16-29.82), and ankylosing spondylitis (AS) (OR 4.52, 95% CI 1.13-18.10), the researchers reported.
Included in the analysis were 202 patients who participated in three controlled clinical trials and 231 controls matched for age, sex, and BMI. An exercise test was performed in all patients and controls using Bruce or Ellestad protocols.
Disease activity was considered moderate in patients with RA and AS, and mild in patients with systemic lupus erythematosus (SLE).
The most frequent cardiovascular risk factors in the three groups of patients were overweight (BMI of 25 or higher), obesity (BMI of 35 or higher), and hypertension. Smoking was more frequent in patients with RA and AS compared with controls.
As assessed by the exercise test, resting heart rate (HR) was higher and oxygen consumption was lower in the three groups of patients compared with the controls.
The investigators noted that physical inactivity could not explain the higher resting HR in the patients, because the controls were sedentary. In addition, the dosage of glucocorticoids was low in the RA and AS patients: “Thus, the higher resting HR may be related to disease itself and could explain the lower tolerance to exercise, which was verified in this scenario. More longitudinal studies are necessary to clarify our findings,” the researchers said.
The three groups of patients had significantly more exercise test alterations (26.3%-57.3%) than the controls (3.6%-9.0%). Alterations in the patient groups consisted primarily of hypertension during the test, higher HR at rest with poor recovery within the first minute, lower consumption of oxygen, and chronotropic incompetence.
“Epidemiological studies have shown that an abnormal HR response during or after some exercise is recognized as an independent predictor of all causes of mortality,” the investigators noted. “In the same way, chronotropic incompetence is thought to predict higher mortality rates and arterial coronary disease.”
In patients with AS, age (OR 1.13, 95% CI 1.03-1.25), and hypertension (OR 7.14, 95% CI 1.61-31.62) were significant risk factors for an abnormal exercise test. In these patients, each increment in the Ankylosing Spondylitis Disease Activity Score incorporating erythrocyte sedimentation rate score tended to correspond to a higher association with chronotropic incompetence (OR 2.73, 95% CI 0.93-8.0).
No variable could explain the presence of exercise test alterations in lupus patients after adjustment for confounding variables. In these patients, age had a protective role (OR 0.88, 95% CI 0.78-0.99) against exercise test alterations.
Our results demonstrated that patients with systemic inflammatory rheumatic diseases had a higher frequency of a positive exercise test compared with healthy controls, highlighting the practical relevance of performing it before prescribing supervised physical exercise, even in patients with no cardiovascular complaints,” the authors wrote. “To our knowledge, this is the first study to assess the performance of a simple and widely used tool for the evaluation of cardiovascular diseases in patients with systemic inflammatory rheumatic diseases compared with healthy controls.
The exercise test is able to identify pathological conditions during physical efforts, “which would not have been detected in asymptomatic cardiovascular patients and under basal conditions at rest,” the authors noted.
A limitation is the possibility of false exercise tests, particularly in women, in whom the average rate of false positive tests is 38%, the team added.
No financial relationships were noted for any of the authors.
Reviewed by F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner
last updated 08.15.2016
Source Reference: Klemz BN, et al “The relevance of performing exercise test before starting supervised physical exercise in asymptomatic cardiovascular patients with rheumatic diseases” Rheumatology 2016; DOI: 10.1093/rheumatology/kew277.