Tibial artery duplex ultrasound-derived peak systolic velocities may be an objective performance measure after above-knee endovascular therapy for arterial stenosis

Atherosclerosis Associated With COVID-19: Acute, Tends to Severely Involve Peripheral Arteries, and May be Reversible

Arterial stiffness was reported with corona virus disease 2019 (COVID-19). We studied atherosclerosis in COVID-19 directly through duplex ultrasound measurements and their relation to co-morbidities, clinical and laboratory severity markers, and serum interleukin (IL) 6 and 17. Serum IL 6 and 17, average carotid intima-media thickness (cIMT), diameter and peak systolic velocities (PSV) of tibial, ulnar, radial arteries, and ankle brachial index (ABI) were measured in 44 COVID-19 patients and 44 healthy controls. Serum IL6, IL17, PSV, and cIMT were higher while diameter was lower (P ≤ .01) in cases. Clinical severity index correlated positively with age, co-morbidities, ferritin, IL6, IL17, cIMT, and PSV (P ≤ .04) and negatively with diameter and ABI (P = .04). Patients with severe lymphopenia had higher PSV, IL6, and IL17 and lower diameter (P < .00001). Ferritin positively correlated with PSV and negatively with diameter and ABI (P ≤ .01). Those who received an IL6 inhibitor (tocilizumab) showed lower PSV and higher diameter (P ≤ .01). In multiple regression analysis, IL17 and (age, co-morbidities) were related to (PSV, diameter) and cIMT (P ≤ .001, ≤0.02), respectively. COVID-19 may be associated with subclinical acute and may be reversible atherosclerosis severely involving peripheral arteries.

Accuracy of the pedal acceleration time to diagnose limb ischemia in patients with and without diabetes using the WIfI classification

INTRODUCTION

Evaluation of limb hemodynamics using the ankle-brachial index (ABI) may be difficult due to skin lesions, extensive necrosis, and obesity, such as commonly present in patients with diabetes with chronic limb-threatening ischemia (CLTI). We hypothesized that the pedal acceleration time (PAT) correlates with ABI and Wound, Ischemia, and foot Infection (WIfI) scores in patients with diabetes to serve as a new modality to accurately stage CLTI.

METHODS

A single-center, cross-sectional study included patients with and without diabetes > 18 years with CLTI. Limbs were categorized in three grades of ischemia based on the ABI (ABI < 0.8, < 0.6, and < 0.4) and in two classes based on WIfI stages of amputation risk. Receiver operator characteristic (ROC) curves were used to determine PAT sensitivity, specificity, and accuracy to predict lower-limb ischemia.

RESULTS

A total of 141 patients (67 nondiabetic and 74 diabetic) and 198 lower limbs (94 nondiabetic and 104 diabetic) met the inclusion criteria. In patients without diabetes, the accuracy of PAT for detecting an ABI < 0.8 was 85%; for detecting an ABI < 0.6 was 85%; and for detecting an ABI < 0.4 was 87%. In patients with diabetes, the accuracy of PAT in detecting an ABI < 0.8 was 91%; for detecting an ABI < 0.6 was 79%; and for detecting an ABI < 0.4 was 88%. In patients without diabetes, the accuracy for detecting WIfI stages of moderate and high amputation risk was 77% and for patients with diabetes was also 77%.

CONCLUSIONS

PAT shows high correlation with the ABI as well as with the WIfI stages of amputation risk and the grades of ischemia, with high accuracy.

Tibial artery velocities in the diagnosis and follow-up of peripheral arterial disease

Physiologic assessment of lower limb peripheral artery occlusive disease is based on indirect physiologic measurement of ankle-brachial systolic pressure index (ABI) and recording ultrasound tibial artery waveforms. Duplex ultrasound testing affords direct tibial artery imaging and assessment of pulsed-Doppler tibial artery waveforms, which is more accurate then measurement of ABI for peripheral artery occlusive disease severity assessment. Tibial artery peak systolic velocity (PSV) is of particular value in the evaluation of patients with incompressible tibial arteries producing a falsely elevated ABI. Calculation of the ankle-profunda index (average tibial artery PSV/proximal profunda femoris artery PSV) also correlates with ABI reduction and can be used as an additional measure of peripheral artery occlusive disease. Tibial artery PSVs can be used to supplement ABI as an objective outcome measure after peripheral arterial interventions, and this aspect of duplex scanning warrants further clinical research.