In patients with persistent dyspnea following a pulmonary embolism, rehabilitation should be considered as a treatment option, according to findings from a randomized, controlled trial comparing usual care to a twice-weekly, 8-week physical exercise program.
The prevalence of persistent dyspnea, functional limitations, and reduced quality of life (QoL) after pulmonary embolism (PE) ranges from 30% to 50% in published studies. While the underlying mechanisms remain unclear and are likely multifactorial, Øyvind Jervan, MD, and colleagues reported, research suggests that deconditioning and psychological factors contribute substantially to post-PE impairment. Optimal management remains unknown.
The investigators randomized adult patients 1:1 from two hospitals (Osfold Hospital and Akershus University Hospital) with PE identified via computed tomography pulmonary angiography 6-72 months prior to study inclusion to either a supervised outpatient exercise program or usual care. The once- or twice-weekly home-based program was tailored to each participant and included a 90-minute educational session on the cardiopulmonary system, diagnosis and treatment of PE and its possible long-term effects, the benefits of exercise and physical activity, and the management of breathlessness. Also during the intervention period, participants were given a simple home-based exercise program to be performed once or twice weekly. Differences between groups in the Incremental Shuttle Walk Test (ISWT), a standardized walking test that assesses exercise capacity, was the primary endpoint. Secondary endpoints included an endurance walk test (ESWT) and measures of symptoms and QoL.
Among 211 participants (median age 57 years; 56% men), the median time from diagnosis to inclusion was 10.3 months. Median baseline walking distance on the ISWT was 695 m with 21% achieving the 1,020-m maximum distance. At follow-up, a between-group difference of 53.0 m favored the rehabilitation group (89 evaluable subjects; 87 in usual care) (P = .0035). While subgroup analysis revealed a greater difference for those with shorter time from diagnosis (6-12 months vs. 12.1-72 months), the between-group differences were nonsignificant. Also, no ISWT differences between the intervention and control group were found for those with higher pulmonary embolism severity and dyspnea scores. The walk endurance test revealed no between-group differences.
Scores at follow-up on the Pulmonary Embolism-QoL questionnaire favored the rehabilitation group (mean difference –4%; P = .041), but there were no differences in generic QoL, dyspnea scores, or the ESWT.
“The present study adds to the growing evidence of the benefits of rehabilitation after PE,” the researchers stated. Although several recent studies have shown rehabilitation after PE results that were promising, the authors pointed out that most of these studies have been small or have lacked a control group, with great variations between them with respect to time, mode, and duration of intervention. In addition, the current study is the largest one addressing the effect of rehabilitation after PE to demonstrate in subjects with persistent dyspnea a positive effect on exercise capacity and QoL.
The researchers also commented that the small detected mean difference of 53 m in walking distance was lower than has been considered a worthwhile improvement by some, and its clinical relevance can be debated. Other studies, however, have used mean group differences of 40-62 m as clinically meaningful. The authors underscored also that the ISWT data were subject to a considerable ceiling effect which may underestimate the effect size.
Addressing study limitations, the researchers added that: “The rehabilitation program in the present study consisted mainly of exercise training. It is unknown whether the addition of occupational therapy, psychology, or dietary therapy would provide additional benefits for the participants. Most participants had mild symptoms, which may have limited the potential benefits of our rehabilitation program.”
The project was funded by Østfold Hospital Trust. Dr. Jervan reported no relevant conflicts of interest.