Structured pain-free exercise progressively improves ankle-brachial index and walking ability in patients with claudication and compressible arteries: an observational study

Abstract

In patients with peripheral artery disease (PAD), supervised exercise at near-moderate pain improves walking ability but not ankle-brachial index (ABI) values. In a retrospective observational study, we determined vascular and functional effects of a 6-month structured pain-free exercise program in patients with claudication and compressible vessels. Four-hundred and fifty-nine consecutive patients were studied. Segmental limb pressures were measured and ABI calculated during circa-monthly hospital visits. The 6-min (6MWD) and the pain-free walking distance (PFWD) during the 6-min walking test were determined. Two daily 8-min sessions of slow–moderate in-home walking at increasing metronome-paced speed were prescribed. After excluding patients with unmeasurable ABI or incompletion of the program, 239 patients were studied. Safe and satisfactory (88%) execution of the prescribed training sessions was reported. During the visits, bilateral ABI improved (+ 0.07; p < 0.001) as well as the segmental pressures in the more impaired limb, with changes already significant after 5 weeks of slow walking. Both systolic and diastolic blood pressure decreased overtime (F = 46.52; p < 0.001; F = 5.52; p < 0.001, respectively). 6MWD and PFWD improved (41[0‒73]m p < 0.001 and 107[42‒190]m p < 0.001, respectively) with associated decrease of walking heart rate (F = 15.91; p < 0.001) and Physiological Cost Index (F = 235.93; p < 0.001). The variations of most parameters at different visits correlated to the training load calculated. In a regression model, the PFWD variations directly correlated with rate sessions completed, training load and ABI change and inversely with the baseline value (R2 = 0.27; p < 0.001). In the PAD population studied, moderate pain-free exercise improved ABI with associated progressive functional and cardiovascular changes occurring regardless of subjects characteristics.

A Fitness-Fatigue Model of Performance in Peripheral Artery Disease: Predicted and Measured Effects of a Pain-Free Exercise Program

“…The study, on the one hand, confirms the effectiveness of the exercise program in the cohort under study, with variations in 6MWD and PFWD (+33 m and +121 m, respectively) exceeding the minimal clinically important difference [ 42 ]. The relevant increase in PFWD also confirms the aerobic effects of the program, possibly supported by previously reported hemodynamic adaptations [ 26 , 28 , 43 ]. On the other hand, as the main result for the present study, the analyses show the correspondence between the changes in functional capacity calculated by the IR model as a result of the structured progressive training load and those obtained in vivo in patients enrolled in the TiTo program.…”

“…We previously observed a discrete repetitiveness of the functional response to progressive training based on weekly cycles and on mesocycles of approximately 5–8 weeks [ 24 , 25 , 26 ] in PAD patients enrolled in the TiTo program [ 28 , 31 , 32 , 33 , 34 ]. This fact led us to isolate a period of enrolment to mathematically analyze the training effects on patients by an “impulse-response” model [ 5 ], where the performance is calculated integrating fitness and fatigue according to a linear response to the training load [ 14 ].…”

“…Unlike this approach, a more aerobic program based on short pain-free walking periods was proposed into an original test-in train-out (TiTo) program prescribed at the hospital and performed at home at a controlled speed [ 24 , 25 ]. This program showed good adherence and was associated with functional and hemodynamic adaptations over the course of the rehabilitative phases [ 24 , 25 , 26 , 27 , 28 ]. We hypothesize that a proper combination of training variables structured according to the exercise principles aimed at attaining aerobic adaptations should evoke theoretically predictable progressive changes in walking performance in patients with PAD with equal response independently of sex.…”

Home-Based Exercise in Elderly Patients with Claudication and Chronic Kidney Disease Is Associated with Lower Progressive Renal Function Worsening: A 5-Year Retrospective Study

“…Previous meta-analyses showed that regular exercise had significant beneficial effects on walking ability, blood pressure, heart rate, and BMI reduction in adult CKD patients [ 20 , 24 ], while controversial effects on endothelial function or arterial stiffness were reported [ 47 ]. Significantly lower values of systolic and diastolic blood pressure, consistent with the meta-analysis by Zhang et al [ 24 ], were observed in a retrospective study on a population of PAD patients with concomitant CKD in a high percentage enrolled in the same TiTo program [ 48 ].…”

Beyond the Patient’s Report: Self-Reported, Subjective, Objective and Estimated Walking Disability in Patients with Peripheral Artery Disease

“…These studies were performed in a limited number of patients and often compared the individual report with data collected by validated outcome measures, which were also potentially affected by subjective perception [15]. Unfortunately, physiological, pathological, and training-related factors [12,[16][17][18] may individually alter pain perception [6,10,11,13]. However, technology may enable objective assessment of the limitation during outside walking in a "real-life" situation [9,13,15,19] or quantification by standardized laboratory tests of the critical metabolic factors involved in ischemic pain and associated with the handicap [20,21].…”