Iris Baumgartner

University Hospital of Lausanne, Lausanne, Vaud, Switzerland

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Publications (243)1187.16 Total impact

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    ABSTRACT: For patients with acute iliofemoral deep vein thrombosis, it remains unclear whether the addition of intravascular high-frequency, low-power ultrasound energy facilitates the resolution of thrombosis during catheter-directed thrombolysis. In a controlled clinical trial, 48 patients (mean age 50±21 years, 52% women) with acute iliofemoral deep vein thrombosis were randomized to receive ultrasound-assisted catheter-directed thrombolysis (N=24) or conventional catheter-directed thrombolysis (N=24). Thrombolysis regimen (20 mg r-tPA over 15 hours) was identical in all patients. The primary efficacy end point was the percentage of thrombus load reduction from baseline to 15 hours according to the length-adjusted thrombus score, obtained from standardized venograms and evaluated by a core laboratory blinded to group assignment. The percentage of thrombus load reduction was 55%±27% in the ultrasound-assisted catheter-directed thrombolysis group and 54%±27% in the conventional catheter-directed thrombolysis group (P=0.91). Adjunctive angioplasty and stenting was performed in 19 (80%) patients and in 20 (83%) patients, respectively (P>0.99). Treatment-related complications occurred in 3 (12%) and 2 (8%) patients, respectively (P>0.99). At 3-month follow-up, primary venous patency was 100% in the ultrasound-assisted catheter-directed thrombolysis group and 96% in the conventional catheter-directed thrombolysis group (P=0.33), and there was no difference in the severity of the post-thrombotic syndrome (mean Villalta score: 3.0±3.9 [range 0-15] versus 1.9±1.9 [range 0-7]; P=0.21), respectively. In this randomized controlled clinical trial of patients with acute iliofemoral deep vein thrombosis treated with a fixed-dose catheter thrombolysis regimen, the addition of intravascular ultrasound did not facilitate thrombus resolution. Unique identifier: NCT01482273. © 2015 American Heart Association, Inc.
    Circulation Cardiovascular Interventions 12/2015; 8(1). DOI:10.1161/CIRCINTERVENTIONS.114.002027 · 6.98 Impact Factor
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    ABSTRACT: Type 2 diabetes mellitus and pre-diabetes are risk factors for atherosclerosis and are highly prevalent in patients with coronary artery disease. However, the prevalence of impaired glucose metabolism in patients with peripheral artery disease is not as well elucidated. We aimed at comparing prevalence rates of type 2 diabetes mellitus and pre-diabetes, which were diagnosed according to the current American Diabetes Association criteria, among 364 patients with peripheral artery disease, 529 patients with coronary artery disease and 383 controls. The prevalence of type 2 diabetes mellitus in peripheral artery disease patients was 49.7%. It was significantly higher in these patients than in coronary artery disease patients (34.4%; p < 0.001) and controls (21.4%; p < 0.001). Adjusted for sex, age and body mass index, odds ratios for type 2 diabetes mellitus were 2.0 (95% confidence interval 1.5-2.6) comparing the peripheral artery disease group with the coronary artery disease group (p < 0.001) and 4.0 (2.8-5.8) comparing the peripheral artery disease group with controls (p < 0.001). The prevalence of pre-diabetes among non-diabetic subjects was high in all three study groups (64.5% in peripheral artery disease patients, 63.4% in coronary artery disease patients and 61.8% in controls), without significant between-group differences. In conclusion, the prevalence of type 2 diabetes mellitus is even higher in peripheral artery disease patients than in coronary artery disease patients. This observation underlines the need to consider impaired glucose regulation in the management of peripheral artery disease. © The Author(s) 2015.
    Diabetes & Vascular Disease Research 01/2015; 12(2). DOI:10.1177/1479164114560342 · 3.04 Impact Factor
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    ABSTRACT: BACKGROUND Drug-eluting balloons (DEB) may reduce infrapopliteal restenosis and reintervention rates versus percutaneous transluminal angioplasty (PTA) and improve wound healing/limb preservation. OBJECTIVES The goal of this clinical trial was to assess the efficacy and safety of IN.PACT Amphirion drug-eluting balloons (IA-DEB) compared to PTA for infrapopliteal arterial revascularization in patients with critical limb ischemia (CLI). METHODS Within a prospective, multicenter, randomized, controlled trial with independent clinical event adjudication and angiographic and wound core laboratories 358 CLI patients were randomized 2:1 to IA-DEB or PTA. The 2 coprimary efficacy endpoints through 12 months were clinically driven target lesion revascularization (CD-TLR) and late lumen loss (LLL). The primary safety endpoint through 6 months was a composite of all-cause mortality, major amputation, and CD-TLR. RESULTS Clinical characteristics were similar between the 2 groups. Significant baseline differences between the IA-DEB and PTA arms included mean lesion length (10.2 cm vs. 12.9 cm; p = 0.002), impaired inflow (40.7% vs. 28.8%; p = 0.035), and previous target limb revascularization (32.2% vs. 21.8%; p = 0.047). Primary efficacy results of IA-DEB versus PTA were CD-TLR of 9.2% versus 13.1% (p = 0.291) and LLL of 0.61 +/- 0.78 mm versus 0.62 +/- 0.78 mm (p = 0.950). Primary safety endpoints were 17.7% versus 15.8% (p = 0.021) and met the noninferiority hypothesis. A safety signal driven by major amputations through 12 months was observed in the IA-DEB arm versus the PTA arm (8.8% vs. 3.6%; p = 0.080). CONCLUSIONS In patients with CLI, IA-DEB had comparable efficacy to PTA. While primary safety was met, there was a trend towards an increased major amputation rate through 12 months compared to PTA. (C) 2014 by the American College of Cardiology Foundation.
    Journal of the American College of Cardiology 10/2014; 64(15):1568-76. DOI:10.1016/j.jacc.2014.06.1198 · 15.34 Impact Factor
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    ABSTRACT: Objectives To assess whether duration of limb ischemia would serve as a major predictor for limb and patient survival. Background Peripheral artery disease (PAD) is a major cause of cardiovascular ischemic events and amputation. Knowledge gaps exist in defining and measuring key factors that predict these events. Methods The “FReedom from Ischemic Events: New Dimensions for Survival” (FRIENDS) registry enrolled consecutive patients with limb-threatening PAD at a single tertiary care hospital. Demographic information, key clinical care time segments, functional status and use of revascularization and pharmacotherapy data were collected at baseline and vascular ischemic events, cardiovascular mortality and all-cause mortality were recorded at 30 days and one year. Results A total of 200 patients with median (IQR) age of 76 (65, 84) were enrolled in the registry. Median duration of limb ischemia was 0.75 days for acute limb ischemia (ALI) and 61 days for chronic critical limb ischemia (CLI). Duration of limb ischemia of <12, 12-24, and >24 hours in ALI patients was associated with much higher rates of first amputation (P = 0.0002), and worse amputation-free survival (P = 0.037). No such associations were observed in patients with CLI. Conclusions For individuals with ischemic symptoms less than 14 days, prolonged limb ischemia is associated with higher 30 day and 1 year amputation, systemic ischemic event rates, and worse amputation-free survival. No such associations are evident for individuals with chronic CLI. These data imply that prompt diagnosis and revascularization might improve outcomes for patients with ALI.
    American Heart Journal 10/2014; 168(4). DOI:10.1016/j.ahj.2014.06.013 · 4.56 Impact Factor
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    ABSTRACT: During the last decades, the clinical and research interest in atherosclerosis has been mostly focused on coronary arteries. After the publications of the European Society Guidelines and AHA/ACC Guidelines on Peripheral artery diseases, and of the Registry REduction in Atherothrombosis for Continued Health Registry, there has been an increased interest in atherosclerosis of the lower extremity arteries and its presence in multifocal disease. However, awareness in the general population and the medical community of non-coronary artery diseases, and of its major prognostic implications remain relatively low. The aim of this general review stemming out of an ESC Working Group on Peripheral Circulation meeting in 2011 is to enhance awareness of this complex disease highlighting the importance of the involvement of atherosclerosis at different levels with respect to clinical presentation, diagnosis, and co-existence of the disease in the distinct arterial territories. We also emphasize the need of an interdisciplinary approach to face the broad and complex spectrum of multifocal disease, and try to propose a series of tentative recommendations and measures to be implemented in non-coronary atherosclerosis.
    European Heart Journal 03/2014; DOI:10.1093/eurheartj/ehu071 · 14.72 Impact Factor
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    ABSTRACT: Due to a high burden of systemic cardiovascular events, current guidelines recommend the use of statins in all patients with peripheral artery disease (PAD). We sought to study the impact of statin use on limb prognosis in patients with symptomatic PAD enrolled in the international REACH registry. Statin use was assessed at study enrolment, as well as a time-varying covariate. Rates of the primary adverse limb outcome (worsening claudication/new episode of critical limb ischaemia, new percutaneous/surgical revascularization, or amputation) at 4 years and the composite of cardiovascular death/myocardial infarction/stroke were compared among statin users vs. non-users. A total of 5861 patients with symptomatic PAD were included. Statin use at baseline was 62.2%. Patients who were on statins had a significantly lower risk of the primary adverse limb outcome at 4 years when compared with those who were not taking statins [22.0 vs. 26.2%; hazard ratio (HR), 0.82; 95% confidence interval (CI), 0.72-0.92; P = 0.0013]. Results were similar when statin use was considered as a time-dependent variable (P = 0.018) and on propensity analysis (P < 0.0001). The composite of cardiovascular death/myocardial infarction/stroke was similarly reduced (HR, 0.83; 95% CI, 0.73-0.96; P = 0.01). Among patients with PAD in the REACH registry, statin use was associated with an ∼18% lower rate of adverse limb outcomes, including worsening symptoms, peripheral revascularization, and ischaemic amputations. These findings suggest that statin therapy not only reduces the risk of adverse cardiovascular events, but also favourably affects limb prognosis in patients with PAD.
    European Heart Journal 02/2014; DOI:10.1093/eurheartj/ehu080 · 14.72 Impact Factor
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    ABSTRACT: The effectiveness and durability of endovascular revascularization therapies for chronic critical limb ischemia (CLI) are challenged by the extensive burden of infrapopliteal arterial disease and lesion-related characteristics (e.g., severe calcification, chronic total occlusions), which frequently result in poor clinical outcomes. While infrapopliteal vessel patency directly affects pain relief and wound healing, sustained patency and extravascular care both contribute to the ultimate "patient-centric" outcomes of functional limb preservation, mobility and quality of life (QoL).Methods/design: IN.PACT DEEP is a 2:1 randomized controlled trial designed to assess the efficacy and safety of infrapopliteal arterial revascularization between the IN.PACT AmphirionTM paclitaxel drug-eluting balloon (IA-DEB) and standard balloon angioplasty (PTA) in patients with Rutherford Class 4-5-6 CLI. This multicenter trial has enrolled 358 patients at 13 European centers with independent angiographic core lab adjudication of the primary efficacy endpoint of target lesion late luminal loss (LLL) and clinically driven target lesion revascularization (TLR) in major amputation-free surviving patients through 12-months. An independent wound core lab will evaluate all ischemic wounds to assess the extent of healing and time to healing at 1, 6, and 12 months. A QoL questionnaire including a pain scale will assess changes from baseline scores through 12 months. A Clinical Events Committee and Data Safety Monitoring Board will adjudicate the composite primary safety endpoints of all-cause death, major amputation, and clinically driven TLR at 6 months and other trial endpoints and supervise patient safety throughout the study. All patients will be followed for 5 years. A literature review is presented of the current status of endovascular treatment of CLI with drug-eluting balloon and standard PTA. The rationale and design of the IN.PACT DEEP Trial are discussed.. IN.PACT DEEP is a milestone, prospective, randomized, robust, independent core lab-adjudicated CLI trial that will evaluate the role of a new infrapopliteal revascularization technology, the IA-DEB, compared to PTA. It will assess the overall impact on infrapopliteal artery patency, limb salvage, wound healing, pain control, QoL, and patient mobility. The 1-year results of the adjudicated co-primary and secondary endpoints will be available in 2014.Trial registration: NCT00941733.
    Trials 02/2014; 15(1):63. DOI:10.1186/1745-6215-15-63 · 2.12 Impact Factor
    This article is viewable in ResearchGate's enriched format
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    ABSTRACT: Purpose : To assess the extent of early recoil in patients with critical limb ischemia (CLI) undergoing conventional tibial balloon angioplasty. Methods : Our hypothesis was that early recoil, defined as lumen compromise >10%, is frequent and accounts for considerable luminal narrowing after tibial angioplasty, promoting restenosis. To test this theory, 30 consecutive CLI patients (18 men; mean age 76.2±12.1 years) were angiographically evaluated immediately after tibial balloon angioplasty and 15 minutes later. Half the patients were diabetics. Target lesions included anterior and posterior tibial arteries and the peroneal artery with / without the tibioperoneal trunk. Mean tibial lesion length was 83.8 mm. Early elastic recoil was determined on the basis of minimal lumen diameter (MLD) measurements at baseline (MLDbaseline), immediately after tibial balloon angioplasty (MLDpostdilation), and 15 minutes thereafter (MLD15min). Results : Elastic recoil was observed in 29 (97%) patients with a mean luminal compromise of 29% according to MLD measurements (MLDbaseline 0.23 mm, MLD postdilation 2.0 mm, and MLD15min 1.47 mm). Conclusion : Early recoil is frequently observed in CLI patients undergoing tibial angioplasty and may significantly contribute to restenosis. These findings support the role of dedicated mechanical scaffolding approaches for the prevention of restenosis in tibial arteries.
    Journal of Endovascular Therapy 02/2014; 21(1):44-51. DOI:10.1583/13-4486MR.1 · 3.59 Impact Factor
  • DMW - Deutsche Medizinische Wochenschrift 02/2014; 139(6):231-3. DOI:10.1055/s-0033-1359979 · 0.65 Impact Factor
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    ABSTRACT: Patients with ilio-femoral deep-vein thrombosis (DVT) are at high risk of developing the post-thrombotic syndrome (PTS). In comparison to anticoagulation therapy alone, extended venography-guided catheter-directed thrombolysis without routine stenting of venous stenosis in patients with ilio-femoral DVT is associated with an increased risk of bleeding and a moderate reduction of PTS. We performed a prospective single-centre study to investigate safety, patency and incidence of PTS in patients with acute ilio-femoral DVT treated with fixed-dose ultrasound-assisted catheter-directed thrombolysis (USAT; 20 mg rt-PA during 15 hours) followed by routing stenting of venous stenosis, defined as residual luminal narrowing >50%, absent antegrade flow, or presence of collateral flow at the site of suspected stenosis. A total of 87 patients (age 46 ± 21 years, 60% women) were included. At 15 hours, thrombolysis success ≥50% was achieved in 67 (77%) patients. Venous stenting (mean 1.9 ± 1.3 stents) was performed in 70 (80%) patients, with the common iliac vein as the most frequent stenting site (83%). One major (1%; 95% CI, 0-6%) and 6 minor bleedings (7%; 95%CI, 3-14%) occurred. Primary and secondary patency rates at 1 year were 87% (95% CI, 74-94%) and 96% (95% CI, 88-99%), respectively. At three months, 88% (95% CI, 78-94%) of patients were free from PTS according to the Villalta scale, with a similar rate at one year (94%, 95% CI, 81-99%). In conclusion, a fixed-dose USAT regimen followed by routine stenting of underlying venous stenosis in patients with ilio-femoral DVT was associated with a low bleeding rate, high patency rates, and a low incidence of PTS.
    Thrombosis and Haemostasis 01/2014; 111(6). DOI:10.1160/TH13-11-0932 · 5.76 Impact Factor
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    ABSTRACT: There is broad evidence that lowering low-density lipoprotein (LDL) cholesterol will reduce cardiovascular risk. However, in patients on maintenance hemodialysis treatment, lowering LDL cholesterol is not as effective in preventing cardiovascular complications as in the general population. Cholesterol is either endogenously synthesized or absorbed from the intestine. It has been suggested that the benefit of using statins to prevent atherosclerotic complications is less pronounced in people with high absorption of cholesterol. Recent data indicate that patients on hemodialysis have high absorption of cholesterol. Therefore, these patients may benefit from dietary counseling to reduce cholesterol intake, from functional foods containing plant sterols and stanols, and from drugs that interfere with intestinal absorption of sterols (i.e., ezetimibe, bile acid resins, and sevelamer). This review discusses cholesterol homeostasis and the perspective of personalized treatment of hypercholesterolemia in hemodialysis.
    Journal of Renal Nutrition 01/2014; 24(2). DOI:10.1053/j.jrn.2013.11.001 · 1.75 Impact Factor
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    ABSTRACT: Transcatheter (or percutaneous) renal denervation is a novel technique developed for the treatment of resistant hypertension. So far, only one randomised controlled trial has been published, which has shown a reduction of office blood pressure. The Swiss Society of Hypertension, the Swiss Society of Cardiology, The Swiss Society of Angiology and the Swiss Society of Interventional Radiology decided to establish recommendations to practicing physicians and specialists for good clinical practice. The eligibility of patients for trancatheter renal denervation needs (1.) confirmation of truly resistant hypertension, (2.) exclusion of secondary forms of hypertension, (3.) a multidisciplinary decision confirming the eligibility, (4.) facilities that guarantee procedural safety and (5.) a long-term follow-up of the patients, if possible in cooperation with a hypertension specialist. These steps are essential until long-term data on safety and efficacy are available.
    Schweizerische medizinische Wochenschrift 01/2014; 144:w13913. DOI:10.4414/smw.2014.13913 · 1.88 Impact Factor
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    ABSTRACT: Advanced lower extremity peripheral artery disease (PAD), whether presenting as acute limb ischemia (ALI) or chronic critical limb ischemia (CLI), is associated with high rates of cardiovascular ischemic events, amputation, and death. Past research has focused on strategies of revascularization, but few data are available that prospectively evaluate the impact of key process of care factors (spanning pre-admission, acute hospitalization, and post-discharge) that might contribute to improving short and long-term health outcomes. The FRIENDS registry is designed to prospectively evaluate a range of patient and health system care delivery factors that might serve as future targets for efforts to improve limb and systemic outcomes for patients with ALI or CLI. This hypothesis-driven registry was designed to evaluate the contributions of: (i) pre-hospital limb ischemia symptom duration, (ii) use of leg revascularization strategies, and (iii) use of risk-reduction pharmacotherapies, as pre-specified factors that may affect amputation-free survival. Sequential patients would be included at an index "vascular specialist-defined" ALI or CLI episode, and patients excluded only for non-vascular etiologies of limb threat. Data including baseline demographics, functional status, co-morbidities, pre-hospital time segments, and use of medical therapies; hospital-based use of revascularization strategies, time segments, and pharmacotherapies; and rates of systemic ischemic events (e.g., myocardial infarction, stroke, hospitalization, and death) and limb ischemic events (e.g., hospitalization for revascularization or amputation) will be recorded during a minimum of one year follow-up. The FRIENDS registry is designed to evaluate the potential impact of key factors that may contribute to adverse outcomes for patients with ALI or CLI. Definition of new "health system-based" therapeutic targets could then become the focus of future interventional clinical trials for individuals with advanced PAD.
    BMC Cardiovascular Disorders 12/2013; 13(1):120. DOI:10.1186/1471-2261-13-120 · 1.50 Impact Factor
    This article is viewable in ResearchGate's enriched format
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    ABSTRACT: No standardized local thrombolysis regimen exists for the treatment of pulmonary embolism (PE). We retrospectively investigated efficacy and safety of fixed low-dose ultrasound-assisted catheter-directed thrombolysis (USAT) for intermediate- and high-risk PE. Fifty-two patients (65 ± 14 years) of whom 14 had high-risk PE (troponin positive in all) and 38 intermediate-risk PE (troponin positive in 91%) were treated with intravenous unfractionated heparin and USAT using 10 mg of recombinant tissue plasminogen activator per device over the course of 15 h. Bilateral USAT was performed in 83% of patients. During 3-month follow-up, two [3.8%; 95% confidence interval (CI) 0.5-13%] patients died (one from cardiogenic shock and one from recurrent PE). Major non-fatal bleeding occurred in two (3.8%; 95% CI, 0.5-13%) patients: one intrathoracic bleeding after cardiopulmonary resuscitation requiring transfusion, one intrapulmonary bleeding requiring lobectomy. Mean pulmonary artery pressure decreased from 37 ± 9 mmHg at baseline to 25 ± 8 mmHg at 15 h (P < 0.001) and cardiac index increased from 2.0 ± 0.7 to 2.7 ± 0.9 L/min/m(2) (P < 0.001). Echocardiographic right-to-left ventricular end-diastolic dimension ratio decreased from 1.42 ± 0.21 at baseline to 1.06 ± 0.23 at 24 h (n = 21; P < 0.001). The greatest haemodynamic benefit from USAT was found in patients with high-risk PE and in those with symptom duration < 14 days. A standardized catheter intervention approach using fixed low-dose USAT for the treatment of intermediate- and high-risk PE was associated with rapid improvement in haemodynamic parameters and low rates of bleeding complications and mortality.
    European Heart Journal 12/2013; DOI:10.1093/eurheartj/eht531 · 14.72 Impact Factor
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    ABSTRACT: In patients with acute pulmonary embolism (PE), systemic thrombolysis improves right ventricular (RV) dilatation, is associated with major bleeding, and is withheld in many patients at risk. This multicenter randomized controlled trial investigated whether ultrasound-assisted catheter-directed thrombolysis (USAT) is superior to anticoagulation alone in the reversal of RV dilatation in intermediate-risk patients. Fifty-nine patients (63±14 years) with acute main or lower lobe PE and echocardiographic right-to-left ventricular dimension (RV/LV) ratio ≥1.0 were randomized to receive unfractionated heparin (UFH) and an USAT regimen of 10-20 mg rt-PA over 15 hours (N = 30, USAT group), or UFH alone (N = 29, heparin group). Primary outcome was the difference in the RV/LV ratio from baseline to 24 hours. Safety outcomes included death, major and minor bleeding, and recurrent venous thromboembolism (VTE) at 90 days. In the USAT group, the mean RV/LV ratio was reduced from 1.28±0.19 at baseline to 0.99±0.17 at 24 hours (p<0.001); in the heparin group, mean RV/LV ratio was 1.20±0.14 and 1.17±0.20, respectively (p=0.31). The mean decrease in RV/LV ratio from baseline to 24 hours was 0.30±0.20 versus 0.03±0.16 (p<0.001), respectively. At 90 days, there was one death (in the heparin group), no major bleeding, 4 minor bleedings (3 in the USAT group and 1 in the heparin group; p=0.61), and no recurrent VTE. In PE patients at intermediate risk, a standardized USAT regimen was superior to anticoagulation with heparin alone in reversing RV dilatation at 24 hours, without an increase in bleeding complications. Identifier: NCT01166997.
    Circulation 11/2013; DOI:10.1161/CIRCULATIONAHA.113.005544 · 14.95 Impact Factor
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    ABSTRACT: Purpose : To assess the need for clinically-driven secondary revascularization in critical limb ischemia (CLI) patients subsequent to tibial angioplasty during a 2-year follow-up. Methods : Between 2008 and 2010, a total of 128 consecutive CLI patients (80 men; mean age 76.5±9.8 years) underwent tibial angioplasty in 139 limbs. Rutherford categories, ankle-brachial index measurements, and lower limb oscillometries were prospectively assessed. All patients were followed at 3, 6, 12 months, and annually thereafter. Rates of death, primary and secondary sustained clinical improvement, target lesion (TLR) and target extremity revascularization (TER), as well as major amputation, were analyzed retrospectively. Primary clinical improvement was defined as improvement in Rutherford category to a level of intermittent claudication without unplanned amputation or TLR. Results : All-cause mortality was 8.6%, 14.8%, 22.9%, and 29.1% at 3, 6, 12, and 24 months. At the same intervals, rates of primary sustained clinical improvement were 74.5%, 53.0%, 42.7%, and 37.1%; for secondary improvement, the rates were 89.1%, 76.0%, 68.4%, and 65.0%. Clinically-driven TLR rates were 14.6%, 29.1%, 41.6%, 46.2%; the rates for TER were 3.0%, 13.6%, 17.2%, and 27.6% in corresponding intervals, while the rates of major amputation were 1.5%, 5.5%, 10.1%, and 10.1%. Conclusion : Clinically-driven TLR is frequently required to maintain favorable functional clinical outcomes in CLI patients following tibial angioplasty. Dedicated technologies addressing tibial arterial restenosis warrant further academic scrutiny.
    Journal of Endovascular Therapy 10/2013; 20(5):707-713. DOI:10.1583/13-4375MR.1 · 3.59 Impact Factor
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    ABSTRACT: Background/aimObesity is a risk factor for chronic venous disease. However, the mechanisms behind this association are poorly understood. We tested the hypothesis that obese subjects have a higher diurnal leg volume increase compared to non-obese subjects.Methods In this prospective cohort study including obese (BMI 30 kg/m(2)) and non-obese (BMI 25 kg/m(2)) subjects without venous insufficiency, lower leg volume was assessed by optoelectronic volumetry in the morning and in the evening. All subjects underwent duplex ultrasound and light reflection rheography (venous pump power and venous refill time, VRT) to investigate lower extremity venous function. A pedometer was carried between the morning and evening visit to assess the daily number of footsteps. A backward multivariable linear regression model was used to determine factors associated with diurnal lower leg volume increase.Results42 limbs in 24 obese subjects and 29 limbs in 15 non-obese subjects were analyzed. Obese subjects had larger common femoral vein diameters (17.1±2.4 mm vs 15.5±2.4 mm, P<0.01) and slower peak, mean and minimal velocities (25.1±10.6 cm/s vs 44.3±14.3 cm/s; 6.8±2.4 cm/s vs 12.7±5.6 cm/s; -0.2±6.4 cm/s vs -6.3±11.9 cm/s; P<0.01 for all) than non-obese subjects. VRT was shorter in obese subjects (40.5±15.0 s vs 51.0±12.1 s, P<0.01) and decreased significantly in the course of the day only in obese subjects (P<0.01). Obesity, male gender, CEAP class, total time between the two visits, and difference between morning and evening VRT were positively associated with higher lower leg volume increase; morning VRT and the total number of footsteps showed a negative association (P<0.04 for all).Conclusion Obesity was found to be an independent predictor of higher diurnal leg volume increase. One potential mechanism is a progressive failure of venous valve function in the course of the day in obese subjects.International Journal of Obesity accepted article preview online, 13 September 2013. doi:10.1038/ijo.2013.178.
    International journal of obesity (2005) 09/2013; DOI:10.1038/ijo.2013.178 · 5.22 Impact Factor
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    ABSTRACT: Despite the fact that numerous studies pursued the strategy of improving collateral function in patients with peripheral artery disease (PAD), there is currently no method available to quantify collateral arterial function of the lower limb. Pressure-derived collateral flow index [CFIp=(Poccl-CVP)/(Pao-CVP); pressure values in mmHg)] of the left superficial femoral artery (SFA) was obtained in patients undergoing elective coronary angiography using a combined pressure/Doppler wire (n=30). Distal occlusive pressure (Poccl) and toe oxygen saturation (SaO2) were measured for 5 minutes (min) under resting conditions, followed by an exercise protocol (repetitive plantar-flexion movements in supine position, n=28). In all patients, balloon occlusion of the SFA over 5 min was painless under resting conditions. CFIp increased during the first 3 min from 0.451±0.168 to 0.551±0.172 (P=0.0003), while SaO2 decreased from 98±2% to 93±7% (P=0.004). Maximal changes of SaO2 were inversely related to maximal CFIp (r(2)=0.33, P=0.003). During exercise, CFIp dropped within 1 min from 0.560±0.178 to 0.393±0.168 (P<0.0001) and reached its minimum after 2 min of exercise (0.347±0.176) while SaO2 declined to a minimum of 86±6% (P=0.002). Twenty-five patients (89%) experienced pain or cramps/tired muscles, while 3 (11%) remained symptom-free for an occlusion time of 10 min. CFIp values were positively related to the pain-free time span (r(2)=0.50, P=0.002). Quantitatively assessed collateral arterial function at rest determined in the non-stenotic SFA is sufficient to prevent ischemic symptoms during a total occlusion of 5 minutes. During exercise, there is a decline in CFIp indicating a supply-demand mismatch via collaterals or - alternatively - a steal phenomenon. Identifier: NCT01742455.
    Circulation 07/2013; 128(7). DOI:10.1161/CIRCULATIONAHA.112.000516 · 14.95 Impact Factor
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    ABSTRACT: Objective To assess the impact of an orthostatic challenge on arterial and venous hemodynamics and its relation to lower leg volume. Methods Hemodynamic parameters of 18 healthy subjects (six men; mean age, 38 ± 11 years) were assessed in the left proximal superficial femoral artery and femoral vein in supine position and during a 10-minute orthostatic challenge using duplex sonography. Lower leg volume was measured using an optoelectronic device. Results During orthostatic challenge, vein diameter increased significantly while artery diameter decreased compared with the supine position (P < .01 for both). Arterial and venous blood flow in the supine (baseline) position was similar (P = .54). During the first 2 minutes of orthostatic challenge, both arterial and venous blood flow significantly decreased, with a more important decrease in venous blood flow (P < .01 compared with artery). Following this nadir, venous blood flow increased above baseline levels, followed by a plateau flow similar to baseline. Arterial flow returned to flow level inferior to baseline values (P < .05). Lower leg volume increased from 2348 ± 399 mL to 2423 ± 433 (P < .001) within the first 5 minutes with no further increase thereafter. Conclusions A 10-minute orthostatic challenge has a marked impact on both arterial and venous hemodynamics with a multiphasic change of venous and arterial flow. Lower leg volume increase correlates with venous and arterial flow response. These findings help to better understand the role of gravitational force in various vascular diseases of the lower extremities.
    07/2013; 1(3):250–256. DOI:10.1016/j.jvsv.2012.12.001
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    ABSTRACT: BACKGROUND: Stenting has been shown to improve patency after femoral artery revascularization in comparison to balloon angioplasty (PTA). Limited data are available evaluating endovascular treatment for obstructive lesions of the popliteal artery (PA). METHODS AND RESULTS: This prospective, randomized, multi-centre trial compares primary nitinol stent (NS) placement to PTA in patients with peripheral artery disease Rutherford-Becker class (RC) 2-5 who had a de-novo lesion in the PA. The primary study endpoint was 1-year primary patency defined as freedom from target lesion restenosis (luminal narrowing of ≥50%) detected with duplex ultrasound. Secondary endpoints included target lesion revascularization (TLR) rate and changes in RC. Provisional stent placement was considered as TLR and loss of primary patency.Two-hundred-forty-six patients were included in this trial. The mean target lesion length was 42.3mm. One-hundred-ninety-seven patients were available for the1-year follow-up. The 1-year primary patency rate was significantly higher in the NS group (67.4%) than in the PTA group (44.9%, P=0.002). TLR rates were 14.7% and 44.1% (P=0.0001). However, when provisional NS placement was not considered as TLR and loss in patency no significant differences prevailed between the study groups (67.4% vs. 65.7%, P=0.92 for primary patency). Approximately 73% of patients in the PTA group and 77% in the NS group showed an improvement of at least one RC (P=0.31). CONCLUSIONS: Primary NS of obstructive lesions of the popliteal artery achieves superior acute technical success and higher 1-year primary patency, only if provisional stenting is considered as TLR. Provisional stenting, as part of a PTA strategy has equivalent 1-year patency, and should be preferred over primary stenting. CLINICAL TRIAL REGISTRATION INFORMATION: Identifier: NCT00712309.
    Circulation 05/2013; 127(25). DOI:10.1161/CIRCULATIONAHA.113.001849 · 14.95 Impact Factor

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  • 2015
    • University Hospital of Lausanne
      Lausanne, Vaud, Switzerland
  • 2013
    • Universitäts-Herzzentrum Freiburg - Bad Krozingen
      باد کروزینگن, Baden-Württemberg, Germany
  • 1996–2013
    • Inselspital, Universitätsspital Bern
      • • Department of Angiology
      • • Swiss Cardiovascular Center Bern
      • • Department of Cardiac and Vascular Surgery
      • • University Institute of Diagnostic, Interventional and Pediatric Radiology
      • • Department of Cardiology
      • • Department of General Internal Medicine
      Berna, Bern, Switzerland
  • 2012
    • Ospedale Regionale di Mendrisio
      Mendrisio, Ticino, Switzerland
  • 2011
    • Medical University of Silesia in Katowice
      Catowice, Silesian Voivodeship, Poland
  • 2005–2011
    • Universität Bern
      • Institut für Anatomie
      Berna, Bern, Switzerland
  • 2008
    • Pierre and Marie Curie University - Paris 6
      Lutetia Parisorum, Île-de-France, France
  • 1996–2007
    • University of Zurich
      Zürich, Zurich, Switzerland
  • 2000
    • Tufts University
      • Department of Medicine
      Medford, MA, United States
  • 1998
    • St. Elizabeth's Medical Center
      Boston, Massachusetts, United States