Comparison of Diagnostic Accuracy between Pulse Volume Recording Parameters and Exercise-Ankle-Brachial Pressure Index in Patients with Ankle-Brachial Pressure Index above 0.9.

Objective: The objective of this study was to clarify whether or not pulse volume recoding (PVR) parameters have screening capability equivalent to ankle-brachial pressure index after walking (Ex-ABI) for patients with 0.91 or higher ABI. Patients and Methods: The subjects were 87 patients (147 limbs) with symptoms of lower extremities with 0.91 or higher ABI. In all patients, upstroke time (UT), percentage of mean artery pressure (%MAP) of PVR and Ex-ABI were measured, and computed tomographic angiography (CTA) was concomitantly performed. Results: Area under the curve (AUC) of receiver operating characteristics (ROC) curves of Ex-ABI, %MAP, and UT were 0.90, 0.70, and 0.81, respectively. A significant difference was noted in AUC between Ex-ABI and %MAP (p <0.001). When the cut-off values were set at %MAP ≥45% and UT ≥180 msec, the accuracies of %MAP and UT were markedly lower than that of Ex-ABI. When the cut-off values were corrected to the values determined from the ROC curves (%MAP ≥41, UT ≥164 msec), the diagnostic accuracy of UT increased markedly. Conclusion: In patients with 0.91 or higher ABI, screening capability of PVR parameters was markedly lower than that of Ex-ABI, but UT has screening capability close to that of Ex-ABI when the cut-off value is corrected downward.

Utility of Exercise-Induced Zero TBI Sign in Patients on Maintenance Hemodialysis.

It is uncertain whether exercise-induced zero toe brachial index sign (e-ZETS) is beneficial to prevent advanced perfusion disturbance in maintenance hemodialysis (HD) patients. In HD patients, we compared the clinical findings and prognoses among 22 toes in a resting zero toe brachial index sign (r-ZETS) group, 22 toes in an e-ZETS group, and 63 toes in a non-e-ZETS group. The hemodynamics of the lower extremities in the e-ZETS group is intermediate between the r-ZETS and non-e-ZETS groups. As the result of a 36-month follow- up observation, the r-ZETS avoidance rate was significantly lower in the e-ZETS group (63.6%; P <0.001) than the non-e-ZETS group (98.4%), showing that it was difficult to avoid advanced perfusion disturbance. The e-ZETS in HD patients may appear before r-ZETS, being beneficial as a predictor for advanced perfusion disturbance. (This is a translation of J Jpn Coll Angiol 2015; 55: 125-129.).

Exercise-ankle brachial pressure index with one-minute treadmill walking in patients on maintenance hemodialysis.

BACKGROUND: The ankle-brachial pressure index (ABI) is widely used as a standard screening method for arterial occlusive lesion above the knee. However, the sensitivity of ABI is low in hemodialysis (HD) patients. Exercise stress (Ex-ABI) may reduce the false negative results. PATIENTS AND METHODS: After measuring resting ABI and toe-brachial pressure index (TBI), ankle pressure and ABI immediately after walking (Post-AP, Post-ABI) were measured using one-minute treadmill walking in 52 lower limbs of 26 HD patients. The definition of peripheral arterial occlusive disease (PAD) required an ABI value of less than 0.90, TBI value of less than 0.60, and decrease of more than 15% of the Post-ABI value and 20 mmHg of Post-AP in Ex-ABI. Computed tomographic angiography (CTA) was performed in 32 lower limbs of 16 HD patients. PAD is defined as presence of stenosis of more than 75% in the case of lesions from an iliac artery to knee on CTA. RESULTS: The accuracy of Ex-ABI (Sensitivity, 85.7%; Specificity, 77.7%) was higher than those of ABI (Sensitivity, 42.9%; Specificity, 83.3%) or TBI (Sensitivity, 78.6%; Specificity, 61.1%). CONCLUSION: Ex-ABI with one-minute treadmill walking is the most useful tool for the screening of arterial occlusive lesions above the knee in maintenance HD patients.

Robustness of the oxygen uptake efficiency slope to exercise intensity in patients with coronary artery disease.

Oxygen uptake efficiency slope (OUES) and ventilatory efficiency (VE/VCO2 slope) are widely used as submaximal measurements of cardiopulmonary exercise testing as the evaluator or prognosticator of cardiac diseases. However, very few studies have compared the effects of submaximal exercise on these measurements. A total of 58 patients with coronary artery disease underwent maximal cardiopulmonary exercise testing on a treadmill. We compared the values obtained from the first 75% (VE/VCO2 slope75 and OUES75) and 90% (VE/VCO2 slope90 and OUES90) of the exercise period with the entire duration (VE/ VCO2 slope100 and OUES100). Although OUES100, OUES90 and OUES75 were virtually identical, submaximal calculations of VE/VCO2 slope underestimated the measurements. The Bland-Altman method revealed that submaximal measurements of OUES agreed very well with maximal OUES (limits of agreement -5.0% to +6.0% for OUES90, and -11.5% to +12.9% for OUES75). However, the submaximal calculations of VE/ VCO2 slope showed rather poor agreement with the maximal calculations (limit of agreement -11.8% to +3.1% for VE/VCO2 slope90, and -20.8% to +5.3%% for VE/VCO2 slope75). These results revealed that both the OUES and the VE/VCO2 slopes are not overly influenced by exercise.

Oxygen uptake efficiency slope as monitoring tool for physical training in chronic hemodialysis patients.

The purpose of this study was to clarify the utility of oxygen uptake efficiency slope (OUES) as a monitoring tool, and to investigate the effects of physical training in chronic hemodialysis (HD) patients. Seventeen patients (Trained Group) received physical training 2-3 times per week for 20 weeks at the intervals between exercise tests. Patients underwent a combination training of bicycle ergometry, walking and jogging for 30 min duration. The intensity of physical training was adjusted to maintain the exercising heart rate at between 50 and 60% of the peak heart rate. Twelve patients (Control Group) lived without physical training throughout the 20 weeks. Both the Groups received the symptom limited exercise tests before and after the 20 week physical training. Minute ventilation (VE), carbon dioxide output (VCO2) and oxygen uptake (VO2) were continuously measured during the exercise tests. Oxygen uptake efficiency slope was derived from the logarithmic relation between VO2 and VE during an incremental exercise test. In the Trained Group, OUES after physical training (30.1 +/- 5.8) was significantly (P < 0.01) higher than that before physical training (25.2 +/- 2.6), while in the Control Group, OUES did not change in this study period of 20 weeks. In the Trained Group, changes in OUES correlated with those in the maximum oxygen uptake (r = 0.78, P < 0.001) and the anaerobic threshold (r = 0.61, P < 0.01). It was suggested that OUES was applicable as a monitoring tool for cardiorespiratory functional reserve during physical training in HD patients.