The Relationship Between Peripheral Artery Disease Symptomatology and Ischemia

Abstract

Background Fewer than half of individuals with peripheral artery disease (PAD) experience classic claudication and the relationships between PAD typical or atypical symptom intensity, location, and description (classic or atypical) with ischemic changes have not previously been reported. Objective The primary purpose of this study was to evaluate the relationship between self-reported PAD symptom intensity and calf tissue ischemia measured using the tissue saturation index (TSI) during treadmill exercise. The location and descriptors of atypical PAD symptoms in the presence of calf tissue ischemia were also identified. Methods Adults with PAD with exercise-limiting ischemic symptoms were asked to: (a) rate symptom intensity using a numerical rating scale (NRS) from 0 to 5 (0 = no pain, 1 = onset of pain, 5 = maximal pain); (b) provide symptom locations and descriptors; and (c) wear a near-infrared spectroscopy device to obtain calf TSI values during treadmill exercise. Multilevel models with TSI as the outcome variable were estimated during exercise and recovery. Covariates included were: exercise time, recovery time, baseline TSI, exercise rating, recovery rating, ABI, age, race, sex, BMI, diabetes, neuropathy, and smoking. Results During three successive bouts of treadmill exercise for 40 participants (80% Caucasian males; average age 68 years, SD = 9.2), the most rapid decline in TSI occurred between the start of exercise and symptom onset (NRS = 1). The TSI nadir was often reached prior to report of maximum discomfort (NRS = 5) and changes in TSI were related to exercise time (p < .001), baseline TSI (p < .001), exercise ratings (p < .001), and ABI (p < .05). During recovery, TSI increased steadily for most participants as pain eased. In the recovery model, changes in TSI were associated with recovery ratings (p < .001) and ABI (p < .03). Out of 120 treadmill exercise tests, 69.2% were stopped due to discomfort in the calf with classic descriptors reported only half the time (55.4%). Discussion Exploratory analyses revealed ischemic symptoms extended beyond classic claudication locations and descriptors. Future research should evaluate changes in TSI relative to atypical locations and descriptors to improve understanding of the full range of ischemic symptoms experienced by individuals with PAD.

The Use of Near Infrared Spectroscopy to Evaluate the Effect of Exercise on Peripheral Muscle Oxygenation in Patients with Lower Extremity Artery Disease: A Systematic Review

“…In line with these findings, Gardner et al found that the change in TTM correlated significantly with the change in maximal walking time (r=.52, p<.001 and r=.43, p=.006 for home-based and supervised groups, respectively) (26). As TTM commonly appears prior to initial pain experience, these moderate correlations might be explained by the objective and subjective mismatch in pain perception and perseverance following an exercise program (34).…”

“…and is associated with better ambulatory outcomes (9,32,34). However, only one study found statistically significant results, whereas two others observed trends towards enhanced recovery after submaximal exercise intensity (21) or recovery relative to total exercise time (29).…”

One-year follow-up of patients screened for lower extremity arterial disease

“…An explanation for this could be that those patients in the follow-up examinations who were initially diagnosed as LEAD-positive by a specialist after the first screening had already received LEAD-specific medications which reduced or even fully eliminated the symptoms by the time the follow-up examination happened. This again emphasizes the importance of approaching the process of diagnosing LEAD with multiple methods, as diagnosis based solely on ABI can be misleading and leave patients mistakenly categorized as negative despite their symptoms, which can ultimately result in patients unable to receive adequate treatment [17,23,34,35].…”

Resting TcPO2 levels decrease during liner wear in persons with a transtibial amputation

“…The relationship between symptom intensity and ischemia in PDA is complex and often highly individual. For example, TcPO2 measures recorded during treadmill walking have shown that severe ischemia and pain do not need to occur simultaneously, and that pain can disappear despite persistent significant ischemia, independent of location [43,44]. Nevertheless, Schorr et al reported that roughly 69% of 120 treadmill exercise tests needed to be stopped due to pain [44].…”