Bruno Vielle

Transcutaneous Oxygen Pressure Measurements on the Buttocks During Exercise to Detect Proximal Arterial Ischemia Comparison With Arteriography

Background—We sought to identify whether transcutaneous oxygen tension (tcPo2) measurements could be used to noninvasively detect lesions in the arterial network supplying blood flow to the hypogastric circulation. Methods and Results—A study was undertaken in vascular patients with suspected (PC, n=43) and not with suspected (NPC, n=34) proximal ischemia. TcPo2 was measured on both buttocks and with a chest reference electrode. Arteriography on the right or left side was positive for stenoses (≥75%) or occlusion of one or more of the following arteries: the aorta, the common iliac arteries, or the internal iliac arteries. The arteriography was compared with the resting tcPo2 values (REST) and with the minimal value (MIN) and maximal change from rest normalized to eventual chest changes (DROP) recorded during or after a treadmill test. REST, MIN, and DROP were, respectively, as follows in positive versus negative arteriograms (mean±SD; in mm Hg): 80.2±10.9 versus 78.6±11.5 (P >0.05), 55.2±20.0 versus 69.9±15.8 (P <0.001), and −31.8±17.6 versus −9.5±6.4 (P <0.0001) in PC and 78.9±14.0 versus 80.5±14.3 (P >0.05), 64.4±21.0 versus 75.1±14.6 (P <0.02), and −24.1±13.5 versus −8.7±4.8 (P <0.0001) in NPC. In PC and NPC respectively, with a cutoff point of −16 and −15 mm Hg, DROP showed, respectively, 83%/82% and 79%/86% sensitivity/specificity in the diagnosis of positive arteriograms. Conclusions—Proximal ischemia is a frequent finding in vascular patients. TcPo2 measurement on the buttocks during exercise is a sensitive and specific indicator for lesions in the arterial tree toward the hypogastric circulation. Potentially it could objectively assess the response to endovascular or surgical approaches to iliac lesions.

Comparison between isoproterenol and nitroglycerin sensitized head-upright tilt in patients with unexplained syncope and negative or positive passive head-up tilt response☆

It is unknown if the head-upright tilt test in patients who receive isoproterenol and nitroglycerin can identify different populations with vasovagal syncope. The aim of this study was to compare the positive or negative responses to passive tilt between isoproterenol- and nitroglycerin-sensitized upright tilt. Ninety-six patients referred for unexplained recurrent syncope underwent passive tilt (45 minutes at 70 degrees angle), which was then systematically followed, within the same session and in a random order, by a 20-minute tilt at a 70 degrees angle after administration of nitroglycerin (NTG-tilt) and 10-minute tilt at a 70 degrees angle with a continuous infusion of isoproterenol (ISO-tilt). NTG-tilt led to significantly more positive responses than passive tilt or ISO-tilt (55% vs 34% vs 42%, respectively). In the subgroup of patients with a positive response during passive tilt, the percentage of positive responses with NTG-tilt was significantly higher than with ISO-tilt (94% vs 67%). The agreement between NTG-tilt and ISO-tilt was very weak (Kappa coefficient 0.06). In the subgroup of patients with a negative response during passive tilt, the percentage of positive responses between NTG-tilt and ISO-tilt was similar (35% vs 29%). The agreement between NTG-tilt and ISO-tilt was good (Kappa coefficient 0.34). NTG-tilt led to a higher number of positive responses than ISO-tilt, especially when passive tilt outcome was positive. These 2 pharmacologic agents may identify 2 different subpopulations of patients because of their specific pharmacologic actions.

Endofibrosis in athletes: is a simple bedside exercise helpful or sufficient for the diagnosis?

Objective:Ankle-to-brachial index (ABI) can be easily performed by all physicians. The Ruffier-Dickson (RD) test is an easy procedure to attain moderate exercise at the bedside for physicians who do not have an ergometer. Design:Retrospective analysis. Setting:Tertiary care, institutional practice. Patients:Fifty-three asymptomatic athletes and 22 patients suffering from unilateral pain due to histologically proven exercise-induced arterial endofibrosis (EIAE). Intervention:Brachial and ankle systolic blood pressures were measured in the supine position on the suspected leg in EIAE or left leg in controls, at rest (rest) and at the first minute of the recovery from incremental maximal cycle ergometer exercise (maxCE) and Ruffier-Dickson (RD) exercise tests. Main Outcome Measures:Comparison of ABIrest, ABImaxCE, and ABIRD in discriminating patients from normal subjects, using receiver operating characteristics (ROC) curves. Results:Area (±SE of area) of ROC curve was 0.76 ± 0.06 for ABIrest, 0.83 ± 0.05 for ABIRD (nonsignificant from rest), and 0.99 ± 0.01 for ABImaxCE (P < 0.01 from ABIRD and P < 0.001 from ABIrest). An ABImaxCE below 0.48 was 100% specific and 80% sensitive for EIAE. For the RD test, a 100% negative predictive value was only attained for postexercise ABI values higher than 0.92. Conclusion:ABI after maximal cycle ergometer exercise is more accurate than ABI after an RD test to search for unilateral EIAE in athletes.

Objective determination of the predefined duration of a constant-load diagnostic tests in arterial claudication

OBJECTIVE The predefined duration to arbitrarily stop the tests during constant-load treadmill exercise is a subject of debate and widely variable in the literature. We hypothesized that the upper and lower limits for predefined durations of constant-load 3.2 km/hour 10% grade tests could be derived from the distribution of walking distances observed on a treadmill in a population of subjects referred for claudication or from the optimal cutoff point distance on a treadmill to confirm a limitation self-reported by history. METHODS We conducted a retrospective analysis using a referral center, institutional practice, and ambulatory patients. We studied 1290 patients (86% male), 62.1 +/- 11.2 years of age, 169 +/- 8 cm height, 75.7 +/- 14.2 kg weight. Patients performed a standard constant-load treadmill test: 3.2 km hour(-1), 10% slope, maximized to 1000 meters (approximately 20 minutes). We analyzed the maximal walking distance self-reported (MWD(SR)) by history and the maximal walking distance measured on the treadmill (MWD(TT)). Patients reporting MWD(SR) >or=1000 meters were considered unlimited by history. RESULTS Only 197 patients (15.3%) completed the 20-minute treadmill test. Among the 504 patients who did not stop before 250 meters, 47.8% stopped within the next 250 meters (were unable to walk 500 meters). This proportion falls to 7.5% among the 213 patients who did not stop before 750 meters. When the final goal was to estimate whether the treadmill test can discriminate patients with or without limitation by history, area under the receiver operating characteristic (ROC) curve was 0.809 +/- 0.016 (95% confidence interval [CI], 0.778-0.841; P < .0001), the best diagnostic performance was attained for an MWD(TT) of 299 meters (approximately 6.15 minutes). CONCLUSION In patients undergoing constant-load treadmill exercise with a protocol of 3.2 km hour(-1) and 10% slope: a predefined duration of 7 minutes could be proposed as a lower limit for the predefined duration of the tests specifically if one aims at confirming the limitation by history with treadmill testing. Owing to the low risk that patients that could walk 750 meters (approximately 15 minutes) will have to stop in the next 250 meters, 15 minutes seems a reasonable upper limit for the predefined test duration in clinical routine.

Aging reduces the accuracy of self-reported walking limitation in patients with vascular-type claudication

BACKGROUND The published correlations between treadmill performance and the Walking Impairment Questionnaire (WIQ) score are generally fair. We hypothesized that the slope of the relationship of maximal treadmill walking time to WIQ would be lower in older than in younger patients, resulting in (1) a fair correlation in the population considered as a whole and (2) different cutoff points of the WIQ score to predict the ability to complete 5 minutes of treadmill walking in different age groups. METHODS A 9-month prospective study was performed among patients referred for vascular-type claudication. Patients were divided into three age groups by years: <60 (group 1, n = 91), 60 to 70 (group 2, n = 80), and >70 (group 3, n = 77). Patients self-completed the WIQ, which was corrected with a nurse, if necessary, and then completed a treadmill test. We calculated the correlation coefficient and slope of the relationship between the WIQ and maximal treadmill walking time. We used receiver operating characteristics curve analysis to estimate the accuracy of the WIQ score to determine the ability of the patients to complete 5 minutes of treadmill walking. RESULTS Differences in slopes were significant between groups 1 vs 2 (P = .02), 2 vs 3 (P < .002), and 1 vs 3 (P < .001). The R(2) for the regression lines also tended to decrease but was only significant between two extremes (1 vs 2, P = .11; 2 vs 3, P = .07; 1 vs 3, P < .001). In patients aged <60 years (group 1), a WIQ score of 47 predicted the ability to complete a 5-minute test on treadmill with 86.8% accuracy (area under the receiver operating characteristics curve, 0.906; P < .001). The accuracy in predicting treadmill results from the WIQ score was fair in group 2 and nonsignificant in group 3. CONCLUSIONS Prediction of treadmill walking capacity from the WIQ score should account for age. The TransAtlantic Inter-Society Consensus suggests that self-reported limitation has an equal weight as measured walking distance in the treatment choices and follow-up of patients with peripheral arterial disease. The WIQ should probably be used with caution in clinical routine, and constant-load treadmill testing is probably not the ideal candidate in elderly patients. New or adapted tools are likely needed in such patients but remain to be studied.

Heart rate recovery after constant-load exercise tests is decreased in proportion to the importance (severity and diffusion) of exercise-induced lower-limb ischaemia

Background:  Conditions that may influence heart rate recovery at 1 min of recovery from exercise (HRR1: end‐exercise heart rate minus heart rate 1 min after exercise) are not fully understood. We hypothesized that the ‘importance’ (both local severity and regional diffusion) of peripheral skeletal muscle ischaemia is associated with low HRR1.

Simultaneous pain intensity rating and quantification of ischemia throughout exercise and recovery in proximal versus distal arterial claudication

Data on simultaneous hemodynamic changes and pain rating estimation in arterial claudication while walking are lacking. This study was conducted to determine if a difference in transcutaneous oxygen pressure (tcpO2) exists between proximal and distal localization at pain appearance (PAINapp), maximal pain (PAINmax) and pain relief (PAINrel) in proximal or distal claudication and if a relationship exists between tcpO2 changes and pain intensity. We analyzed the pain rating (Visual Analog Scale (VAS)) to lower limb ischemia, measured with the decrease from rest of oxygen pressure (DROP) tcpO2 index during constant-load treadmill tests in patients with calf (n = 41) or buttock (n = 19) claudication. Calves versus buttocks results were analyzed with ANOVA tests. The R2 correlation coefficient between individual VAS versus DROP was calculated. Ischemia intensity versus pain rating changes were correlated. Significant ischemia was required for pain appearance, but pain disappeared despite the persistence of ischemia. We observed no statistical difference for DROP at PAINapp, PAINmax or PAINrel between proximal or distal claudication. A significant correlation between pain rating versus DROP was found: from PAINapp to PAINmax, R2 = 0.750 (calves) and 0.829 (buttocks), and from PAINmax to PAINrel, R2 = 0.608 (calves) and 0.560 (buttocks); p<0.05. Pain appeared after a significant decrease of hemodynamic parameters but disappeared while parameters were not normalized. No difference in pain rating was found in proximal versus distal claudication.

Ankle to brachial systolic pressure index at rest increases with age in asymptomatic physically active participants

Background It is commonly acknowledged that the ability to use the ankle–brachial index (ABI), a reliable way to diagnose atherosclerosis, decreases with age in the general population. The aim of this study was to determine the relationship between resting ABI and age in different populations. Methods 674 physically active participants with (active high risk, ACTHR) or without (active low risk, ACTLR) cardiovascular risk factors or/and sedentary (SED) subjects, aged 20–70 years. Systolic arterial pressure was recorded at rest and simultaneously with automatic sphygmomanometers at the arms and ankles. ABI was calculated as the ratio of the lowest, highest or mean ankle pressure to the highest arm pressure. Results Proportion of ABImin<0.90 was 10.3% in SEDHR subjects versus 0.5% and 1.2%, respectively, in ACTHR and ACTLR groups. The averaged ABI value of each group was in the normal range in all groups (ABI>0.90) but was significantly lower in SEDHR compared with all active participants (p<0.001). Regression lines from ABImean versus age could lead to approximately +0.05 every 15 years of age in apparently healthy active participants (ACTLR). Conclusion ABI at rest increases with the increase in age in the groups of low-risk asymptomatic middle-aged trained adults. The previously reported decrease in ABI with age is found only in SEDHR subjects, and is very likely to rely on the increased prevalence of asymptomatic arterial disease in this group. The increase of ABI with age is consistent with the ‘physiological’ stiffness observed in ageing arteries even in the absence of ‘pathological’ atherosclerotic lesions. Trial registration number NIH clinicaltrial.gov: NCT01812343.

Post-exercise ankle blood pressure and ankle to brachial index after heavy load bicycle exercise

The American Heart Association (AHA) recommendations for diagnosing peripheral artery disease (PAD) after exercise are a decrease >20% of ankle brachial index (ABI) or >30 mm Hg of ankle systolic blood pressure (ASBP) from resting values. We evaluated ABI and ASBP values during incremental maximal exercise in physically active and asymptomatic patients. Patients (n = 726) underwent incremental bicycle tests with pre‐ and post‐exercise recording of all four limbs arterial pressures simultaneously. Univariate and multivariate analyses were performed to define the correlation between post‐exercise ABI with various clinical factors, including age. Thereafter, the population was divided into groups of age: less than 40 (G < 40), from 40 to 44 (G40/44) from 45 to 49 (G45/49), from 50 to 54 (G50/54), from 55 to 59 (G55/59), from 60 to 64 (G60/64), and 65 and above (G ≥ 65) years. Results are mean ± SD. * is two‐tailed P < .05 for ANOVA with Dunnetts post‐hoc test from G40. Changes from rest in ASBP were −3 ± 22 (G < 40), −2 ± 20 (G40/44), 4 ± 22* (G45/49), 10 ± 25* (G50/54), 18 ± 21* (G55/59), 23 ± 27* (G60/64), and 16 ± 22* (G ≥ 65) mm Hg. Decreases from rest in ABI were 32 ± 9 (G < 40), 33 ± 9 (G40/44), 29 ± 8 (G45/49), 27 ± 10* (G50/54), 24 ± 7* (G55/59), 22 ± 12* (G60/64), and 21 ± 12* (G ≥ 65) % of resting ABI. Maximal incremental exercise results in ABI and ASBP changes are mostly dependent on age. The AHA limits for post‐exercise ABI are inadequate following maximal incremental bicycle testing. Future studies detecting PAD in active patients should account for the effect of age.

Can the scoring of the walking estimated limitation calculated by history (WELCH) questionnaire be simultaneously simplified and improved

BACKGROUND The WELCH questionnaire includes 4 items (A, B, C and D) and estimates the maximal walking time (MWT) on treadmill in patients with claudication. Its scoring was empirically defined. We aimed to test various methods for scoring to estimate whether the scoring of the WELCH could be improved or simplified. PATIENTS AND METHODS In 423 patients, we tested 8 methods (from H1 to H8) of weighing D or calculating α, β and γ in the equation MWT = (αA + βB + γC) * D. RESULTS While the WELCH Pearson r was 0.639 and area under ROC curve for the ability to walk 5 minutes on treadmill was 0.795 for the reference empirical method, tested hypotheses resulted in values ranging 0.566 to 0.661 for the Pearson r values and 0.750 to 0.809 for the areas under ROC curve respectively. CONCLUSIONS None of the tested methods simultaneously improved the correlation to MWT, remained simple enough to be scored by mental calculation and ranged between intuitive minimal and maximal values. The original empirical scoring seems a good compromise between accuracy and simplicity.