Accuracy of maximal acceleration time of pedal arteries to diagnose critical limb-threatening ischemia.

INTRODUCTION: Maximal acceleration time of distal arteries of the foot (ATmax) is correlated to ankle-brachial index (ABI) and toe-brachial index (TBI), and seems very promising in diagnosing severe peripheral artery disease (PAD) and especially critical limb-threatening ischemia (CLTI). Our goal was to confirm the cut-off value of 215 ms to predict a toe pressure (TP) ⩽ 30 mmHg. METHODS: A 4-month retrospective study was conducted on patients addressed for suspicion of PAD. Demographic data, ABI, TBI, and Doppler ultrasound scanning parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded. RESULTS: A total of 137 patients with 258 lower limbs were included. ATmax was highly correlated to TBI (r = -0.89, p < 0.001). With the cut-off value of 215 ms, ATmax was effective to diagnose TP ⩽ 30 mmHg with a sensitivity of 93% [95% CI 77-99], a specificity of 96% [95% CI 92-98], a positive predictive value of 73% [95% CI 56-86], a negative predictive value of 99% [95% CI 97-100], and an area under the receiver operating characteristics curve of 0.99 [95% CI 0.98-1.00]. ATmax also showed promising results to rule out PAD in healthy patients. CONCLUSION: ATmax is a reliable diagnostic tool to diagnose low TP and could be a new easily performed hemodynamic criterion for diagnosis of CLTI.

Arterial Blood-Flow Acceleration Time on Doppler Ultrasound Waveforms: What Are We Talking About?

In recent years, the assessment of systolic acceleration in lower-extremity peripheral artery disease (PAD) has been brought back into the spotlight, whatever measure is used: time (in s) or acceleration (in cm.s-2). Acceleration time (also called systolic rise time) and maximal acceleration are two different but very useful measurements of growing interest in PAD. A background of the historical development, physics rationale, semantics, and methods of measurement, as well as their strengths and weaknesses, are discussed herein. Acceleration time is a powerful tool for predicting significant arterial stenosis or for estimating the overall impact of PAD as it is highly correlated to the ankle or toe pressure indexes. It could even become a new diagnostic criterion for critical limb ischemia. Similarly, maximal systolic acceleration ratios are highly predictive of carotid or renal stenosis. However, the literature lacks reference standards or guidelines for the assessment of such variables, and their measurement techniques seem to differ between authors. We propose herein a semantic and measurement statement order to clarify and help standardize future research.

Diagnostic Performance of Pulsed Doppler Ultrasound of the Common Femoral Vein to Detect Elevated Right Atrial Pressure in Pulmonary Hypertension.

Right atrial pressure (RAP) is an important prognostic criterion in pulmonary hypertension (PH). The main goals were to evaluate the following: (i) the accuracy of Doppler assessment of common femoral vein flow waveform to detect elevated RAP and (ii) the diagnostic accuracy of RAP assessed by echocardiography (eRAP). Fifty-seven patients, addressed for right heart catheterization, were included in a retrospective cross-sectional study during a 6-month period. Forty-five patients (78.9%) had PH confirmed by RHC. Elevated RAP was defined by RAP ≥ 10 mmHg. Femoral venous stasis index (FVSI) was highly correlated to RAP on both univariate (p < 0.001) and multivariate analysis (p = 0.003), and showed good diagnostic performances to detect elevated RAP (specificity: 92.3% [80.0-99.3], diagnosis accuracy: 90.4 [77.4-97.3], positive likelihood ratio: 12.5 [3.01-51.97]). Diagnosis accuracy of eRAP was only 51.2% (36.2-66.1). FVSI is independently correlated to RAP and a useful tool to predict elevated RAP in PH patients.

Accuracy of Acceleration Time of Distal Arteries to Diagnose Severe Peripheral Arterial Disease.

CONTEXT: Ankle-brachial index (ABI) and toe-brachial index (TBI) are the recommended tests for the diagnosis of lower extremity peripheral artery disease (PAD) and the assessment of its severity, whereas Doppler ultrasound (DUS) is usually used to localize vascular lesions. However, the performance of DUS as an alternative to TBI and ABI measurement is unknown. OBJECTIVE: The goals were (i) to evaluate the correlation between DUS parameters of distal arteries of the lower extremities with TBI in patients with PAD; (ii) to evaluate the correlation between DUS parameters of distal arteries with ABI; and (iii) to assess the diagnostic accuracy of maximal acceleration time of pedal arteries to detect toe pressure ≤30 mmHg. METHODS: An observational retrospective study was conducted for 1 year on patients with the diagnosis of PAD on DUS. Demographic data, ABI, TBI, and DUS parameters of the dorsal pedis and lateral plantar arteries (DPA and LPA) were recorded. RESULTS: Seventy-seven patients with 88 limbs were included, aged 69 [interquartile range: 11 years] with 28.6% of diabetic patients. The highest acceleration time of either DPA or LPA (ATmax) was the most correlated to TBI on both univariate (r = -0.78, p < 0.0001) and multivariate analysis (p < 0.0001). DUS parameters had a weaker correlation with ABI. ATmax > 215 ms showed high diagnosis accuracy to a toe pressure of 30 mmHg or less [sensitivity of 86% [0.57-0.98] and negative predictive value of 97% [0.89-1.00]]. CONCLUSION: ATmax demonstrates a high correlation with TBI in patients with PAD, and high diagnostic accuracy for detection of critical limb ischemia. Based on these results, ATmax can represent the next step in evaluating PAD severity with DUS, in patients with advanced lower extremity PAD.