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Background: The optimal degree of heparin anticoagulation for peripheral vascular interventions (PVIs) has not been defined. We sought to correlate total heparin dose and peak procedural activated clotting time (ACT) with postprocedural outcomes in patients undergoing PVI., Methods and Results: We studied 4743 patients who received heparin during PVIs in a regional, multicenter registry. From those, 1246 had recorded peak procedural ACT with the same point-of-care device. Periprocedural and in-hospital outcomes were compared between patients who received a total heparin dose <60 U/kg (n=2161) and ≥60 U/kg (n=2582). Similarly, outcomes were evaluated between groups with a peak procedural ACT <250 seconds (n=855) and ≥250 seconds (n=391). Technical and procedural success as well as intraprocedural thrombotic events did not differ between groups. Patients with heparin dose ≥60 U/kg had a higher rate of postprocedural hemoglobin drop ≥3 g/dL (7.09% versus 5.09%, respectively, P=0.004) and a higher transfusion rate compared with those with heparin dose <60 U/kg (4.92% versus 3.15%, respectively, P=0.002). In multivariate analysis, independent predictors of bleeding requiring transfusion were total heparin dose ≥60 U/kg, ACT ≥250 seconds, female sex, age ≥70 years, prior anemia, prior heart failure, low creatinine clearance, hybrid vascular surgery, rest pain, and below-knee intervention. In propensity-matched, risk-adjusted models and after hierarchical modeling, total heparin dose ≥60 U/kg and ACT ≥250 seconds remained strong predictors of post-PVI drop in hemoglobin ≥3 g/dL or transfusion., Conclusions: During PVI, higher total heparin dose (≥60 U/kg) and peak ACT ≥250 seconds were predictors of postprocedural transfusion. The high technical and procedural success in all groups suggests that use of weight-based heparin dosing with a target ACT <250 seconds in PVI may minimize the bleeding risk without compromising procedural success or increasing thromboembolic complications.

Aims: We performed a meta-analysis of randomized controlled trials comparing routine stenting (ST) with percutaneous transluminal angioplasty (PTA) for symptomatic superficial femoral-popliteal artery (SFPA) disease., Methods and Results: Ten trials were pooled randomizing patients to ST (n = 724 limbs) or PTA with provisional stenting (n = 718 limbs) with a follow-up period of 9-24 months. The mean lesion length was similar in the two groups (45.8 mm in the ST group and 43.3 mm in the PTA group). We calculated the summary risk ratios (RRs) for immediate technical failure, restenosis, and target vessel revascularization (TVR) using random-effects models. The immediate technical failure was higher in the PTA group than in the ST group [17.1 vs. 5.9%, respectively, RR = 0.28, 95% confidence interval (CI) = 0.15-0.54, P < 0.001], with 10.3% of the PTA patients undergoing stenting because of suboptimal result. There was a trend for lower restenosis in the ST group (37.6% in ST vs. 45.3% in PTA, RR = 0.85, 95% CI = 0.69-1.06, P = 0.146), but no difference in the need for TVR (20% in ST vs. 20.2% in PTA, RR = 0.98, 95% CI = 0.78-1.23, P = 0.89). In an analysis restricted to nitinol stents, there was a trend towards reduction in TVR (RR = 0.79, 95% CI = 0.59-1.06, P = 0.12)., Conclusion: Despite the higher immediate success, routine stenting was not associated with a significant reduction in the rate of restenosis or TVR. Our data do not support use of routine stenting as the primary endovascular treatment for short SFPA lesions.

Background: This study compared VLTS-589 (plasmid encoding the angiomatrix protein Del-1 in conjunction with poloxamer 188) with poloxamer 188 control, for the treatment of intermittent claudication in patients with moderate to severe peripheral arterial disease., Methods: Subjects with bilateral intermittent claudication and peak walking time (PWT) between 1 and 10 minutes on 2 qualifying (reproducible; within 25% of each other) treadmill tests were enrolled. Patients received VLTS-589 or poloxamer 188 control, administered as 21 intramuscular injections to each lower extremity (42 mL in each extremity). In addition to safety and tolerability, efficacy evaluations compared to baseline included the following: change in PWT at 90 days (primary end point), change in claudication onset time, change in ankle brachial index (ABI), and change in quality of life measures., Results: A total of 105 patients were randomized and treated. During the 30, 90, and 180 days follow-up, mean PWT, claudication onset time, and ABI were significantly increased compared to baseline values in both treatment groups with no significant difference between groups in the primary or secondary end points. In addition, both groups demonstrated significantly improved quality of life at follow-up vs baseline, with no significant differences between groups. Serious adverse events were similar in both groups--none were definitely treatment-related., Conclusion: Intramuscular delivery of both Del-1 expressing plasmid and the control resulted in significant improvement in exercise capacity compared to baseline at 30, 90, and 180 days. There was no difference in outcome measures associated with the Del-1 plasmid.

Background: Critical limb ischemia, a manifestation of severe peripheral atherosclerosis and compromised lower-extremity blood flow, results in a high rate of limb loss. We hypothesized that adenoviral delivery of a constitutively active form of the transcription factor hypoxia-inducible factor-1alpha (ie, Ad2/HIF-1alpha/VP16 or HIF-1alpha) into the lower extremity of patients with critical limb ischemia would be safe and might result in a durable clinical response., Methods and Results: This phase I dose-escalation program included 2 studies: a randomized, double-blind, placebo-controlled study and an open-label extension study. In total, 34 no-option patients with critical limb ischemia received HIF-1alpha at doses of 1x10(8) to 2x10(11) viral particles. No serious adverse events were attributable to study treatment. Five deaths occurred: 3 in HIF-1alpha and 2 in placebo patients. In the first (randomized) study, 7 of 21 HIF-1alpha patients met treatment failure criteria and had major amputations. Three of the 7 placebo patients rolled over to receive HIF-1alpha in the extension study. No amputations occurred in the 2 highest-dose groups of Ad2/HIF-1alpha/VP16 (1x10(11) and 2x10(11) viral particles). The most common adverse events included peripheral edema, disease progression, and peripheral ischemia. At 1 year, limb status observations in HIF-1alpha patients included complete rest pain resolution in 14 of 32 patients and complete ulcer healing in 5 of 18 patients., Conclusions: HIF-1alpha therapy in patients with critical limb ischemia was well tolerated, supporting further, larger, randomized efficacy trials.

The objective of this phase II investigation is to assess the safety and efficacy of a plasmid mediated approach to induce angiogenesis/arteriogenesis with the angiomatrix protein Del-1 (developmentally regulated endothelial locus 1), in subjects with intermittent claudication (IC) secondary to peripheral arterial disease (PAD). VLTS-589 is an investigational nonviral therapeutic comprising a plasmid-expressing Del-1 formulated with poloxamer 188 (facilitating agent). One hundred subjects with bilateral PAD and IC will be randomized after careful screening to bilateral intramuscular delivery of VLTS-589 or placebo. A total of 84 mg of plasmid or placebo will be delivered as 42 intramuscular injections (2 ml per injection, 21 injections or 42 ml in each extremity of either plasmid or placebo) in both lower extremities. The subjects in the study will be followed at regular intervals for a year after study drug administration (days 30, 90, 180, and 365) with the primary endpoint being the safety and tolerability of VLTS-589 and change in peak walking time (PWT) at day 90. The secondary endpoints include percent and absolute change in resting ankle brachial Index, claudication onset time, and quality of life measured at various time points. DELTA-1 represents the largest plasmid-based gene transfer trial designed to test the efficacy of a Del-1 as a therapeutic approach in patients with IC caused by PAD. The novel aspects of the protocol include the usage of a Del-1 plasmid-polaxamer formulation to enhance gene transfer at doses that are an order of magnitude different than other comparable trials in a unique bilateral intramuscular dosing pattern to maximize transfection/clinical efficacy and general applicability to patients with PAD.

Extracardiac vascular disease is associated with an increased risk of in-hospital mortality and other complications after coronary interventions, independent from other co-morbidities and baseline characteristics. The underlying cause of this significant association is unclear, but it warrants further investigation in an attempt to improve outcome in this high-risk cohort.

Patients with extracardiac vascular disease were identified from 2,372 consecutive percutaneous coronary intervention (PCI) cases performed between 1997 and 2001. After multivariate adjustment, we found the presence of extracardiac vascular disease to be associated with a significantly higher risk for late mortality (hazard ratio [HR] 1.4, 95% confidence interval [CI] 1.0 to 2.0, p = 0.029). When extracardiac vascular disease was separated into cerebrovascular disease and peripheral vascular disease, cerebrovascular disease was less common but was associated with a trend towards worse survival.

Background: Peripheral vascular disease is a manifestation of systemic atherosclerosis and is associated with an increased risk of cardiovascular morbidity and mortality., Methods and Results: We examined clinical outcomes in 66 consecutive patients undergoing peripheral vascular interventions at our institution between January 2001 and October 2001. At hospital discharge and at 6 months, lifestyle modifications and use of evidence-based therapy was suboptimal. At 6 months, a significant proportion continued to smoke (22.7%) and only half of the patients exercised, controlled their weight, or modified their diet for lipid control. The use of antiplatelet therapy was 77.2%; of angiotensin-converting enzyme, 35.9%; of beta-blockers, 42.5%; and of statins, 50%. Twelve of the 66 patients (18.2%) had a clinical event of death, myocardial infarction, or stroke. An appropriateness algorithm for use of secondary prevention measures was created with the use of evidence-based therapy guidelines, and a composite appropriateness variable was also created. The use of evidence-based therapy was associated with a significant reduction of the composite of death, myocardial infarction, and stroke at 6 months (OR 0.02, 95% CI 0.01 to 0.44, P=0.01)., Conclusions: Atherosclerosis risk factors are very prevalent in patients with peripheral vascular disease, but these patients receive less than optimal treatment after a predominantly technical vascular intervention. Effective secondary prevention with appropriate lifestyle interventions and evidence-based medical therapy needs to be strongly encouraged and implemented in these patients.