Atrial fibrillation patients less physically active than healthy people

Patients with atrial fibrillation (AF) appear to engage in lesser daily physical activity than their healthy counterparts, according to a new study.

“Using objective, daily step count data longitudinally collected over an average of more than 1.5 years, we observed that individuals with AF demonstrate a significant reduction in daily step count, even after adjusting for relevant demographics and other medical comorbidities,” researchers said. “Furthermore, more severe, symptomatic AF was associated with lower daily step count.”

Of the 3,333 participants given fitness tracking devices, 7 percent (n=234; mean age, 62.2±12.1 years; 45 percent female) had AF. Those without AF were significantly younger (mean age, 49.9±13.6 years) and more likely to be female (59 percent; p<0.0001 for both). Medical comorbidities such as smoking, hypertension, diabetes, chronic obstructive pulmonary disease, congestive heart failure, and coronary artery disease, were also more common among AF patients. [Heart Rhythm 2020;17:842-846]

The mean step count per day was 7,585±3,245 steps. On average, AF patients took 723 fewer daily steps than their healthy counterparts. The resulting difference was statistically significant (p=0.001).

Adjusting for potential confounders―such as age, sex, education, smoking, income, and medical comorbidities―attenuated this effect but only slightly. The daily difference dropped to 591 fewer steps taken by AF patients. The difference remained significant (p=0.009).

Most of the AF participants (97 percent; n-=226) were able to complete the Atrial Fibrillation Effect on Quality of Life (AFEQT) survey. The mean score was 80±18 points.

Physical activity appeared to correlate with AF symptoms, as quantified by AFEQT. Each 1-point drop in the survey score was significantly associated with walking 34 fewer steps per day (95 percent confidence interval, 14–55; p=0.001).

Adjusting for covariates modified this relationship: each point decrease in AFEQT was linked to 24 fewer steps a day. The interaction, however, remained significant (p=0.04).

Sensitivity analysis was limited to data obtained in the first 90 days since AFEQT assessment did not significantly alter the main findings.

“Collectively, these findings raise the possibility that a proportion of the poor health outcomes associated with AF are related to disease-associated inactivity and that alleviation of AF symptoms may help facilitate physical activity among those with the disease,” the researchers said.

“These findings are bolstered by our study design, which allowed for objective assessment of physical activity without the need for error-prone recollection and without explicit participant knowledge that daily exercise was being studied in relation to AF symptoms, thus minimizing recall and observer bias,” they added.

In the present study, participants were enrolled from the Health eHeart study. Participants were invited to send in physical activity data collected electronically by a fitness tracking device. AF was assessed by enrollment through self-reports of diagnosis. Those who reported having AF were asked to complete AFEQT to assess symptom severity.