Interventions for Peripheral Arterial Disease: A Systematic Review

Purpose: Peripheral Artery Disease (PAD), affecting 1 in 5 older adults, impacts blood flow to the lower extremities causing cramping or claudication that potentially limits walking, cardiorespiratory response, muscle performance, and quality of life. The purpose of this systematic review is to investigate interventions effective in improving function in individuals with PAD and it’s presenting symptoms. Subjects: Studies reviewed n=21 included Randomized Controlled Trials (RCT’s) and Systematic Reviews (SR’s) with a total of 6,195 subjects ages 60 to 84. For the studies that included the specific subject demographics, there were 3,355 men and 2,202 women with and/or without intermittent claudication. Methods: Literature search was performed on two databases (PubMed and Cochrane Reviews) for randomized controlled trials (RCT’s) and systematic reviews (SR’s) published between 2010 and 2017, using the following search terms: “interventions,” “resistance training,” “strength training,” “treadmill walking,” “intensive walking,” “aquatic therapy,” “ergometry,” and “blood flow restriction” or “BFR” and PAD. Inclusion criteria for study selection included sample size [greater than] 20, any language that is translated in English, subjects with an Ankle Brachial Index (ABI) Data Analysis: The full review of articles was completed by two independent reviewers. Results: Of the 21 studies reviewed 12 RCT’s and 9 SR’s used the following interventions: comparison studies (n=7 studies); resistance training (n= 2 studies), supervised or conventional exercise (n=5 studies), intensive walking programs (n=1 studies), home exercise programs (n=4 studies), and BFR (n=2 studies) in patients with PAD. Outcomes measured to determine the effects of interventions include: Walking Impairment Questionnaire (WIQ), 6MWT, SF-36, time to claudication, maximal walking distance, and aerobic capacity. Of the interventions, standard walking programs, are most effective at improving walking time and distance, time to claudication, 6MWD, Walking Impairment Questionnaire (WIQ), and quality of life (3,4,5,6,7,9,10,11,17). Resistance training has proved to be as effective, if not more effective than walking (8,12,14,16,17,18) using the same outcomes. Other interventions reviewed showed statistically significant outcomes, and may also serve as complimentary or alternative treatments for individuals with PAD (1,2,14). Future research can look into the effects of BFR for PAD, as it has been shown to improve muscle performance in older adults, without having an impact on arterial stiffness (19,20). Conclusion: Although methodologies and interventions widely vary, traditional walking programs are considered the gold standard for improved outcomes for individuals with PAD, however, resistance training is just as effective or better in improving the same outcomes and can serve as a component of or alternative intervention (8,12,14,16,17,18). Cycling, home exercise programs, and walking with poles are other interventions that improved outcomes. Interpretation of the results should take into consideration the following limitations: lack of heterogeneity/homogeneity, subject compliance, lack of standardized interventions across the studies, and presence multi-morbidities. Clinical Relevance: The interventions reviewed are effective in improving outcomes in PAD and are more cost effective than surgical interventions. The presence of comorbidities (i.e. diabetes or other cardiovascular conditions) may attenuate the improvement of symptoms (1,2,15,21) and need to be taken into consideration when measuring exercise tolerance.