Quantification of Soft Tissue Loss among Patients with Peripheral Arterial Disease

Abstract

Objective

Tissue atrophy is known to occur amongst patients with peripheral arterial disease (PAD). We report quantification and assessment of severity of calf tissue atrophy amongst patients with PAD.

Patient types

Calf atrophy amongst patients who presented for peripheral transluminal angioplasty (PTA) at the Institute for Cardiovascular excellence (ICE) in 2012 was assessed using X-ray methods (n = 48). This cohort has the most severe PAD. Patients suspected of having PAD were assessed using lower extremity arterial ultrasound (LAU) and had their calves measured with a tape. This group had patients with (n = 355) and without (n = 245) PAD. Not all of those with PAD needed angiography and PTA thus these represent patients with moderate to severe PAD. The third cohort included patients from National Health and Nutritional Examination survey (NHANES) and included normal patients without PAD (n = 6391), those with abnormal ankle brachial index (ABI) (n = 422). These represent those with mild to moderate PAD. Amongst NHANES patients, those who either had no ABI or un-interpretable ABI were excluded from analysis (n = 2332).

Calf Measurement

Tape measurement of calf circumference followed the method adopted in NHANES and identified the widest portion of the calf with the patient in the seated position. Calf circumference from X-ray involved visualization of both edges of soft tissue at calf level. A visible catheter of known size in the same run was used for calibration. Using measured soft tissue diameter from X-ray calf circumference was calculated.

Data Analysis

Data analysis included descriptive statistics and generalized linear modeling after data cleaning and transformation.

Results

After adjusting for all other factors, the odds of having PAD per centimeter increase in calf circumference are 0.88. Compared with smokers, nonsmokers' odds of PAD are 0.42. Odds of PAD among nonhypertensives are 0.58 in comparison to the hypertensives.

Implications of our findings

Among patients who present to the doctors' office for routine assessment, if calf circumference width were to be measured as a part of physical examination using 36.5 cm as a cutoff to help identify PAD patients. These patients could then undergo a more careful assessment for PAD.