Terutoshi Yamaoka

Essential role of monocyte chemoattractant protein-1 in development of restenotic changes (neointimal hyperplasia and constrictive remodeling) after balloon angioplasty in hypercholesterolemic rabbits

Background—Renarrowing of dilated arterial sites (restenosis) hampers the clinical benefits of coronary angioplasty. Infiltration and activation of monocytes in the arterial wall mediated by monocyte chemoattractant protein-1 (MCP-1) might be a major cause of restenosis after angioplasty. However, there is no direct evidence to support a definite role of MCP-1 in the development of restenosis. Methods and Results—We recently devised a new strategy for anti–MCP-1 gene therapy by transfecting an N-terminal deletion mutant of the MCP-1 gene into skeletal muscles. We used this strategy to investigate the role of MCP-1 in the development of restenotic changes after balloon injury in the carotid artery in hypercholesterolemic rabbits. Intramuscular transfection of the mutant MCP-1 gene suppressed monocyte infiltration/activation in the injured arterial wall and thus attenuated the development of neointimal hyperplasia and negative remodeling. Conclusions—MCP-1–mediated monocyte infiltration is necessary in the development of restenotic changes to balloon injury in hypercholesterolemic rabbits. This strategy may be a useful and practical form of gene therapy against human restenosis.

Endovascular Treatment for Infrainguinal Vessels in Patients With Critical Limb Ischemia OLIVE Registry, a Prospective, Multicenter Study in Japan With 12-Month Follow-up

Background—Recent technical advances have made endovascular treatment (EVT) an alternative first-line treatment for critical limb ischemia. Methods and Results—A prospective multicenter study was conducted to evaluate the clinical outcomes of 314 Japanese critical limb ischemia patients (mean age, 73±10 years) with infrainguinal arterial lesions who underwent EVT. Patients were enrolled from December 2009 to July 2011 and were followed-up for 12 months. The primary end point was amputation-free survival (AFS) at 12 months. Secondary end points were anatomic, clinical, and hemodynamic measures, including 12-month freedom from major adverse limb events. The 12-month AFS rate was 74%, with body mass index <18.5 (hazard ratio [HR], 2.22; P=0.008), heart failure (HR, 1.73; P=0.04), and wound infection (HR, 1.89; P=0.03) associated with a poor prognosis for AFS. The 12-month major adverse limb event-free rate was 88%, with hemodialysis (HR, 1.98; P=0.005), heart failure (HR, 1.69; P=0.02), and Rutherford classification 6 (HR, 2.25; P=0.002) associated with a poor prognosis for major adverse limb events. The median time for wound healing was 97 days, with body mass index <18.5 (HR, 0.54; P=0.03) and wound infection (HR, 0.60; P=0.04) being significant risk factors for unhealed wounds after EVT. At 12 months, 34% had undergone reintervention (bypass surgery, 2.6%; repeat EVT, 31.7%), and 73% were major adverse event–free. Conclusions—The high reintervention rate notwithstanding, EVT was an effective treatment for Japanese critical limb ischemia patients with infrainguinal disease, with satisfactory AFS and major adverse limb event-free rates. The results of this study will be helpful for the future evaluation of critical limb ischemia therapy. Clinical Trial Registration—URL: http://www.umin.ac.jp/ctr. Unique identifier: UMIN000002830.

Angiographic Restenosis and Its Clinical Impact after Infrapopliteal Angioplasty

OBJECTIVE To assess 3- and 12-month angiographic restenosis rates and their clinical impact after infrapopliteal angioplasty. DESIGN Prospective multicenter study. MATERIALS AND METHODS We analyzed 68 critical ischemic limbs (tissue loss: 58 limbs) from 63 consecutive patients due to isolated infrapopliteal lesions who underwent angioplasty alone. Primary endpoint was 3-month angiographic restenosis rate; secondary endpoints were 12-month angiographic restenosis rate, and 3- and 12-month rates of mortality, major amputation and reintervention. Three- and 12-month frequency of ambulatory status and of freedom from ischemic symptoms, and time to wound healing in the ischemic wound group, were compared between restenotic and non-restenotic groups. Angiographic restenosis predictors were assessed by multivariable analysis. RESULTS 95% of cases had 3-month angiography; restenosis rate was 73%: 40% restenosis and 33% re-occlusion. Twelve-month follow-up angiography was conducted for the patients without 3-month angiographic restenosis, and restenosis rate at 12 months was 82%. Non-administration of cilostazol and statin, and chronic total occlusion were 3-month angiographic restenosis predictors. Three- and 12-month mortality was 5% and 12%, respectively. Despite no patients having undergone amputation, 15% had persistent ischemic symptoms, and 48% of limbs underwent reintervention within 12 months. During the same study period, ambulatory status and limbs with complete healing were more frequently observed in the non-restenosis group than in the restenosis group. In the tissue loss group, time to wound healing in the restenosis group was longer than in the non-restenosis group (127 days vs. 66 days, p = 0.02). CONCLUSION The extremely high angiographic restenosis rate after infrapopliteal angioplasty may adversely impact clinical status improvement.

Successful and optimized in vivo gene transfer to rabbit carotid artery mediated by electronic pulse

Several gene transfer methods, including viral or nonviral vehicles have been developed, however, efficacy, safety or handling continue to present problems. We developed a nonviral and plasmid-based method for arterial gene transfer by in vivo electronic pulse, using a newly designed T-shaped electrode. Using rabbit carotid arteries, we first optimized gene transfer efficiency, and firefly luciferase gene transfer via electronic pulse under 20 voltage (the pulse length: Pontime 20 ms, the pulse interval: Poff time 80 ms, number of pulse: 10 times) showed the highest gene expression. Exogenous gene expression was detectable for at least up to 14 days. Electroporation-mediated gene transfer of E. coli lacZ with nuclear localizing signal revealed successful gene transfer to luminal endothelial cells and to medial cells. Histological damage was recognized as the voltage was increased but neointima formation 4 weeks after gene transfer was not induced. In vivo electroporation-mediated arterial gene transfer is readily facilitated, is safe and may prove to be an alternative form of gene transfer to the vasculature.

Clinical efficacy of endovascular therapy for patients with critical limb ischemia attributable to pure isolated infrapopliteal lesions

BACKGROUND Prognosis of endovascular therapy (EVT) for isolated infrapopliteal lesions has not been adequately studied. We investigated and risk-stratified long-term prognosis after EVT for critical limb ischemia (CLI) attributable to isolated infrapopliteal lesions. METHODS Between March 2004 and October 2010, 884 patients (1057 limbs) with CLI attributable to isolated infrapopliteal lesions who underwent EVT with angioplasty alone were enrolled. Outcome measures were freedom from major adverse limb events with perioperative death (MALE+POD) and amputation-free survival. Cox proportional hazards models were used to assess independent predictors for these outcomes. RESULTS Freedom from MALE+POD was 82 ± 1% and 74 ± 2% at 1 and 5 years, respectively. Risk factors associated with MALE+POD were age ≥80 years (adjusted hazard ratio [HR], 0.4; P < .001), nonambulatory status (HR, 2.0; P < .001), albumin <3.0 g/dL (HR, 1.4; P < .0001), Rutherford 6 (HR, 2.2; P < .001), C-reactive protein ≥3.0 mg/dL (HR, 2.1; P < .001), and below-the-ankle disease (HR, 2.0; P < .001). One- and 5-year amputation-free survival was 71 ± 2% and 38 ± 3%, respectively. Risk factors associated with major amputation/mortality were nonambulatory status (adjusted HR, 2.1; P < .001), body mass index <18.5 kg/m(2) (HR, 1.4; P = .02), albumin <3.0 g/dL (HR, 1.8; P < .0001), end-stage renal disease (HR, 1.4; P = .004), ejection fraction <50% (HR, 1.6; P < .001), Rutherford 6 (HR, 1.9; P < .001), C-reactive protein ≥3.0 mg/dL (HR, 1.7; P < .0001), and below-the-ankle disease (HR, 1.8; P < .001). In patients with more than four risk factors, both end points at 1 year were below the 71% suggested efficacy objective performance goal. CONCLUSIONS Long-term clinical outcomes were acceptable after EVT for patients with CLI due to pure isolated infrapopliteal lesion. Risk stratification by baseline characteristics is useful in estimating long-term prognosis.

3-Year Outcomes of the OLIVE Registry, a Prospective Multicenter Study of Patients With Critical Limb Ischemia: A Prospective, Multi-Center, Three-Year Follow-Up Study on Endovascular Treatment for Infra-Inguinal Vessel in Patients With Critical Limb Ischemia.

OBJECTIVES This study sought to investigate the 3-year follow-up results of OLIVE registry patients. BACKGROUND Although favorable 12-month clinical outcomes after endovascular therapy (EVT) in OLIVE registry patients with critical limb ischemia (CLI) from infrainguinal disease have been reported, long-term results after EVT remain unknown. METHODS This was a prospective multicenter registry study that consecutively enrolled patients who received infrainguinal EVT for CLI. The primary outcome was 3-year amputation-free survival (AFS), whereas secondary outcome measures were 3-year freedom from major adverse limb events (MALE), wound-free survival, and wound recurrence rate. Prognostic predictors for each outcome were also elucidated by Cox proportional hazard regression analysis or the log-rank test. RESULTS The completion rate of 3-year follow-up was 95%. Three-year AFS, freedom from MALE, and wound-free survival rates were 55.2%, 84.0%, and 49.6%, respectively. Wound recurrence out to 3 years was 43.9%. After multivariable analysis, age (hazard ratio [HR]: 1.43, p = 0.001), body mass index ≤18.5 (HR: 2.17, p = 0.001), dialysis (HR: 2.91, p < 0.001), and Rutherford 6 (HR: 1.64, p = 0.047) were identified as predictors of 3-year major amputation or death. Statin use (HR: 0.28, p = 0.02), Rutherford 6 (HR: 2.40, p = 0.02), straight-line flow to the foot (HR: 0.27, p = 0.001), and heart failure (HR: 1.96, p = 0.04) were identified as 3-year MALE predictors. Finally, CLI due to isolated below-the-knee lesion was a wound recurrence predictor (HR: 4.28, p ≤ 0.001). Three-year survival, freedom from major amputation, and reintervention rates were 63.0%, 87.9%, and 43.2%. CONCLUSIONS In CLI patients with infrainguinal lesions, 3-year clinical results of EVT were reasonable despite high reintervention and moderate ulcer recurrence rate. (A Prospective, Multi-Center, Three-Year Follow-Up Study on Endovascular Treatment for Infra-Inguinal Vessel in Patients With Critical Limb Ischemia [OLIVE 3-Year Follow-Up Study]; UMIN000014759).

Worse Limb Prognosis for Indirect versus Direct Endovascular Revascularization only in Patients with Critical Limb Ischemia Complicated with Wound Infection and Diabetes Mellitus

OBJECTIVES To investigate factors in patients with critical limb ischemia (CLI) and isolated infrapopliteal lesions that adversely affect outcomes of endovascular therapy (EVT) with or without angiosome-oriented revascularization. METHODS This was a retrospective multicenter study. We used a database of 718 consecutive CLI patients (70 ± 11 years, 75% diabetics, 68% on hemodialysis, 24% Rutherford class 6) with ischemic tissue loss due to isolated infrapopliteal lesions undergoing primary EVT. Primary outcome was MALE (major adverse limb event). Association between indirect EVT (recanalization of a non-angiosome-based artery) and outcome was assessed by Cox proportional hazard regression model. RESULTS C-reactive protein (CRP) level was >3 mg/dL in 32% of cases. Indirect EVT (in 307 CLI patients, 43%), was associated with MALE (p = .04, hazard ratio [95% confidence interval] 1.25 [1.01, 1.55]), and interacted with CRP >3 mg/dL (p < .004) but not with other baseline characteristics. Indirect EVT with CRP >3 mg/dL had higher MALE risk (HR 2.08), and interacted with diabetes mellitus (DM) presence. Indirect EVT with CRP >3 mg/dL and DM had higher MALE risk (HR 2.17). CONCLUSION Limb prognosis was equivalent for direct and indirect endovascular revascularization except in the presence of both diabetes and wound infection, when indirect revascularization has a poorer outcome.

Anatomical Predictors of Major Adverse Limb Events after Infrapopliteal Angioplasty for Patients with Critical Limb Ischaemia due to Pure Isolated Infrapopliteal Lesions

OBJECTIVE To identify anatomical factors associated with major adverse limb events (MALE) after angioplasty as the basis for a novel morphology-driven classification of infrapopliteal lesions. DESIGN Retrospective-multicenter study. MATERIALS AND METHODS Between March 2004 and October 2010, 1057 limbs from 884 patients with CLI due to isolated infrapopliteal lesions were studied. Freedom-from MALE, defined as major amputation or any reintervention, was assessed out to 2 years by the Kaplan-Meier methods. Anatomical predictors and risk stratification for MALE were analyzed by multivariate analysis. RESULTS Freedom-from MALE was 47 ± 1% at 2 years. Lesion calcification, target vessel diameter<3.0 mm, lesion length>300 mm and no below-the-ankle (BA) run-off were positively associated with MALE by multivariate-analysis. The total number of risk factors was used to calculate the risk score for each limbs for subsequent categorization into 3 groups with 0 or 1 (low-risk), 2 (moderate-risk) and 3 or 4 (high-risk) factors. Freedom-from MALE at 2 year-rates was 59% in low-risk, 46% in moderate-risk, and 29% in high-risk, respectively. CONCLUSION Target vessel diameter <3.0 mm, lesion calcification, lesion length > 300 mm and no-BA run-off were associated with MALE after infrapopliteal angioplasty. Risk stratification based on these predictors allows estimation of future incidence of MALE in CLI with isolated infrapopliteal lesions.

Impact of angiosome-oriented revascularization on clinical outcomes in critical limb ischemia patients without concurrent wound infection and diabetes.

Purpose To investigate the impact of angiosome-oriented revascularization on clinical outcomes in critical limb ischemia (CLI) patients excluding those with both diabetes and wound infection. Methods Using a retrospective multicenter database, a propensity score matching analysis was performed of 539 consecutive CLI patients (375 men; mean age 71±11 years) without concurrent wound infection and diabetes who underwent balloon angioplasty of isolated infrapopliteal lesions. Propensity score matching produced 2 groups of 182 patients each who underwent angiosome-oriented direct revascularization (123 men; mean age 72±11 years) or indirect revascularization (125 men; mean age 72±11 years). The groups were compared for wound healing rate, freedom from major adverse limb events (MALE), and amputation-free survival (AFS). Results In the overall population, indirect revascularization was performed in 36.6% (n=197). In the propensity matching analysis, the complete wound healing rate at 12 months was higher in the direct group than the indirect revascularization patients (75% vs. 64%, p=0.01), while freedom from MALE (p=0.99) and AFS (p=0.17) were not significantly different at up to 24 months. In multivariate analysis, indirect revascularization had an independent negative impact on wound healing (adjusted hazard ratio 0.7, p=0.008). Conclusion After propensity matching analysis for CLI patients other than those with both diabetes and wound infection, the wound healing rate was higher after direct revascularization than after indirect revascularization, whereas MALE and AFS were not significantly different.

Propensity Score Analysis of Clinical Outcome After Bypass Surgery vs. Endovascular Therapy for Infrainguinal Artery Disease in Patients With Critical Limb Ischemia

Purpose To compare endovascular therapy (EVT) outcomes to those of bypass surgery (BSG) for infrainguinal artery disease in patients with critical limb ischemia (CLI). Methods A retrospective review was conducted of 1053 CLI patients (1053 first treated limbs) who underwent BSG (n=230) or EVT (n=823) for de novo infrainguinal lesions between January 2004 and December 2009 at 14 Japanese centers. Propensity score analysis was used for risk adjustment in multivariate analysis and for one-to-one matching (n=200 in each group). Amputation-free survival, overall survival, limb salvage, and freedom from major adverse limb events (any repeat revascularization or major amputation) were calculated. Results Mean follow-up was 30±16 months. In the overall series, there was no significant difference at 3 years between the EVT and BSG groups in amputation-free survival (60.5% vs. 62.1%, p=0.84), limb salvage (88.7% vs. 85.4%, p=0.24), or overall survival (65.8% vs. 69.2%, p=0.40). However, freedom from adverse limb events was significantly lower in the EVT group (56.6% vs. 69.2%, p=0.02) at 3 years. In the matched pairs analysis, there was no significant difference in any outcome between BSG and EVT at 3 years: amputation-free survival 66.3% vs. 62.0 (p=0.44), limb salvage 88.8% vs. 84.8% (p=0.44), survival 73.8% vs. 68.8% (p=0.61), and freedom from adverse limb events 61.3% vs. 69.1% (p=0.27). Conclusion Our cohort suggested that the frequency of serious adverse events after EVT was comparable to that after BSG in CLI patients who underwent their first infrainguinal revascularization.