Transradial access for peripheral vascular interventions.

Transradial access for coronary interventions has grown substantially in the last few years. Currently, there is an increased interest in applying this approach to peripheral vascular interventions. This report reviews the current status of transradial peripheral interventions, and offers advice in terms of feasibility, equipment use, and technical challenges.

Study to determine the clinical significance of HEmolysis During Orbital AtheRectomy (CLEAR study).

PURPOSE: To evaluate the incidence of clinically evident hemolysis associated with orbital atherectomy used to treat severe peripheral artery disease. METHODS: The observational CLEAR study enrolled 31 subjects (16 men; mean age 71 ± 10 years, range 44-92) with claudication (58.1%) or critical limb ischemia (38.7%) who underwent orbital atherectomy with the Diamondback 360 system at 4 US centers. The 42 lesions in 31 limbs were located in the superficial femoral (n = 19, 45.2%), popliteal (n = 8, 19.0%), and tibial arteries (n = 15, 35.8%). The majority of lesions (34, 81.0%) were de novo; moderate or severe calcification was identified in 90.5% of cases. Lesion and procedural parameters were analyzed at a core laboratory. Blood samples were collected during and post procedure and analyzed for markers of hemolysis. The primary endpoint was the occurrence of clinically significant hemolysis. The secondary endpoints included the occurrence of any clinical symptoms/signs potentially related to hemolysis. Statistical analysis was performed to identify predictors for hemolysis. RESULTS: Laboratory evidence of hemolysis was seen in 11 (35.5%) subjects. No one met the clinical event criteria, and so the primary endpoint of the study was not reached. The secondary endpoints were hypertensive crisis (1, 3.2%) and transient hemoglobinuria (3, 9.7%). Lower glomerular filtration rates, calcified plaque, long atherectomy runs, and solid crown selection were independent predictors of hemolysis. CONCLUSION: There was no clinically significant hemolysis after orbital atherectomy. The results of this study will enable users to predict conditions that predispose to high levels of red cell hemolysis following orbital atherectomy and to take appropriate measures to limit its occurrence.

Acquired pulmonary vein stenosis resulting in haemoptysis: a case series.

BACKGROUND: Acquired pulmonary vein stenosis (PVS) is an infrequent complication of atrial fibrillation ablation that is often misdiagnosed due to predominant respiratory symptoms. It can result in pulmonary venous hypertension, with varying presentations, ranging from shortness of breath to haemoptysis. CASE SUMMARY: We report two patients with a history of paroxysmal atrial fibrillation treated with radiofrequency ablation and pulmonary vein (PV) isolation, who subsequently developed PVS. Case 1 initially presented with indolent symptoms of shortness of breath and cough. He was initially diagnosed with and treated for pneumonia. In contrast, Case 2 presented with massive haemoptysis, requiring intubation and intensive care unit admission. Both patients were eventually diagnosed with PVS by computed tomography. They were treated with PV angioplasty and stenting. DISCUSSION: While previously limited to the congenital heart disease population, PVS is occurring more frequently now in adult patients as a complication of ablation procedures. It is most effectively treated with angioplasty and stent implantation but has a high rate of recurrence.

Safety and efficacy of transradial aortoiliac interventions.

BACKGROUND: This study compares transradial approach (TRA) aortoiliac angioplasty/stenting to the transfemoral approach (TFA). METHODS: We reviewed our peripheral database for aortoiliac interventions performed between 2007 and 2009. Demographics, clinical characteristics, procedural, and lesion details were collected. The efficacy endpoints included procedural success, ankle-brachial index (ABI) improvement, and time to discharge. The safety endpoints were as follows: occurrence of intra-/periprocedural complications, 30-day MACE, and access-site complications (minor/major). The subjects were divided into two groups, TRA and TFA, and compared using appropriate statistics. RESULTS: Twenty-seven patients had 33 lesions treated via TRA, and 41 patients had 47 lesions treated via TFA access. Baseline demographic differences between the TRA and TFA groups were similar, including mean Rutherford category (2.9 vs. 2.6, P = 0.31) and preintervention ABI (0.64 vs. 0.67, P = 0.80). There was a significantly higher percentage of total occlusions in the TRA group (27.3 vs. 8.5%, P = 0.03). Dye use (238 vs. 213 mL, P = 0.35) and fluoroscopy time (30 vs. 27 min, P = 0.60) were similar. Procedural success rate was similar (87.9 vs. 97.8%, P = 0.15), as well as the improvement in mean ABI (TRA: 0.64-0.77 and TFA: 0.67-0.85, P = 0.77). The time to discharge was significantly shorter for the TRA group (14.4 vs. 20.9 hr, P = 0.003). There were no 30-day MACE or major access-site complications, but minor access-site complications were lower in the TRA group (0.0 vs. 7.3%, P = 0.28), although nonsignificant. CONCLUSIONS: The TRA to aortoiliac interventions is as safe and effective as the TFA with the advantage of a lower rate of access-site complications and shorter hospitalization time.

Orbital atherectomy for symptomatic lower extremity disease.

BACKGROUND: Plaque-debulking technologies have been proposed as alternative treatment options for peripheral arterial disease. Orbital atherectomy (OA), using the DiamondBack360 device, has emerged as one promising modality. METHODS: We evaluated the safety and efficacy of OA in the first 200 lesions treated at our institution. Patient demographics, clinical characteristics, and lesion and procedural variables were collected and analyzed. The primary safety endpoint was the 30-day major adverse events (MAE), including death, myocardial infarction, stroke, unplanned amputation, or target lesion revascularization. Other safety endpoints included access-site complications, occurrence of dissections, perforations, distal embolization, spasm, and hemolysis. The efficacy endpoints were procedural success, need for adjunctive therapy, and improvement in ankle-brachial index. Multivariate analysis was performed to find independent predictors of the safety endpoints. RESULTS: One hundred seventeen (58.5%) lesions were femoral, 31 (15.5%) were popliteal, and 52 (26.0%) were tibial. The procedural success (residual stenosis ≤30%) was comparable between the femoral and tibial lesions (86.3% vs. 92.5%, P = 0.18), but significantly lower for the popliteal lesions when compared with femoral and tibial (64.7% vs. 86.3%, P = 0.058, and 64.7% vs. 92.5%, P = 0.007 respectively). MAE at 30-days occurred in 3 (2.2%) procedures, and major access-site complications also occurred in 3 (2.2%). There were 31 (15.5%) dissections; independent predictors were diabetes mellitus (OR: 7.3, P = 0.008), crown-to-RVD ratio <0.6 (OR: 11.6, P = 0.005), and atherectomy time >360 sec (OR: 11.8, P = 0.001). There were 2 (1.0%) distal embolizations, 6 (3.0%) arterial spasms, and no perforations. Laboratory evidence of hemolysis was noted in 33.8% of cases. CONCLUSION: Orbital atherectomy allows for a significant procedural success, limited need for stenting, and favorable safety profile.

Transradial peripheral vascular interventions.

Recently the importance of post procedure bleeding contributing to both short-term and long-term mortality has lead to a renewed interest in transradial coronary interventions in the United States. It has been long known that the incidence of access site bleeding is dramatically decreased by transradial access but the procedure is only used in 1% of coronary interventions in the United States, far below the rest of the world. In India, Japan and some European centers 50% of interventions are transradial. To extend this benefit of lower incidence of access site complications, we started using a transradial approach for peripheral interventions for the lower extremities, renal and subclavian arteries. By experience, we realized that in many cases the radial approach makes the procedure actually simpler. Also, in many instances, the transradial approach allows discharge of the patient on the same day. In this paper, we describe our approach to lower extremity, renal and subclavian interventional procedures.

Sex-Related Differences in the Outcomes of Endovascular Interventions for Chronic Limb-Threatening Ischemia: Results from the LIBERTY 360 Study.

INTRODUCTION: Previous studies have suggested that women with chroniclimb-threatening ischemia (CLTI) may have worse outcomes than men. The aim of this study was to determine whether there are sex-related differences in outcomes of patients with CLTI undergoing endovascular treatment with current endovascular technologies. PATIENTS AND METHODS: Data were derived from the LIBERTY 360 study (NCT01855412). Hazard ratios and the respective 95% confidence intervals were synthesized to examine the association between sex and all-cause mortality, target vessel revascularization (TVR), major amputation, major adverse event (MAE) and major amputation/death up to 3 years of follow-up. RESULTS: A total of 689 patients with CLTI (female: N=252 vs male: N=437) treated with any FDA approved or cleared device were included. The mean lesion length was 126.9±117.3mm and 127.4±113.3mm for the female and male patients, respectively. Although a slightly higher incidence of in-hospital mortality was observed in the female group (1.2% vs 0.0%, p=0.049), there was no difference in female vs male survival rates during follow-up. However, the risk of major amputation at 18 months was higher for the male group (male vs female: HR: 2.36; 95% CI: 1.09-5.12; p=0.030). No difference between the two groups was detected in terms of TVR or MAE during follow-up. DISCUSSION: Data regarding sex-related disparity in outcomes after endovascular therapy of patients with CLTI are conflicting. Gender-related characteristics rather than biological sex characteristics might be the cause of these conflicting findings. Further studies are needed to evaluate the role of sex in revascularization outcomes among this high-risk population.

N-Acetylcysteine added to volume expansion with sodium bicarbonate does not further prevent contrast-induced nephropathy: results from the cardiac angiography in renally impaired patients study.

We reviewed data from the multicenter CARE (Cardiac Angiography in Renally Impaired Patients) study to see if benefit could be shown for N-acetylcysteine (NAC) in patients undergoing cardiac angiography who all received intravenous bicarbonate fluid expansion. Four hundred fourteen patients with moderate-to-severe chronic kidney disease were randomized to receive intra-arterial administration of iopamidol-370 or iodixanol-320. All patients were prehydrated with isotonic sodium bicarbonate solution. Each site chose whether or not to administer NAC 1,200 mg twice daily to all patients. Serum creatinine (SCr) levels and estimated glomerular filtration rate were assessed at baseline and 2-5 days after receiving contrast. The primary outcome was a postdose SCr increase 0.5 mg/dL (44.2 mumol/L) over baseline. Secondary outcomes were a postdose SCr increase 25% and the mean peak change in SCr. The NAC group received significantly less hydration (892 +/- 236 mL vs. 1016 +/- 328 mL; P < 0.001) and more contrast volume (146 +/- 74 mL vs. 127 +/- 71 mL; P = 0.009) compared with no-NAC group. SCr increases 0.5 mg/dL occurred in 4.2% (7 of 168 patients) in NAC group and 6.5% (16 of 246 patients) in no-NAC group (P = 0.38); rates of SCr increases 25% were 11.9% and 10.6%, respectively (P = 0.75); mean post-SCr increases were 0.07 mg/dL in NAC group versus 0.11 mg/dL in no-NAC group (P = 0.14). In conclusion, addition of NAC to fluid expansion with sodium bicarbonate failed to reduce the rate of contrast-induced nephropathy (CIN) after the intra-arterial administration of iopamidol or iodixanol to high-risk patients with chronic kidney disease.

Cardiac Angiography in Renally Impaired Patients (CARE) study: a randomized double-blind trial of contrast-induced nephropathy in patients with chronic kidney disease.

BACKGROUND: No direct comparisons exist of the renal tolerability of the low-osmolality contrast medium iopamidol with that of the iso-osmolality contrast medium iodixanol in high-risk patients. METHODS AND RESULTS: The present study is a multicenter, randomized, double-blind comparison of iopamidol and iodixanol in patients with chronic kidney disease (estimated glomerular filtration rate, 20 to 59 mL/min) who underwent cardiac angiography or percutaneous coronary interventions. Serum creatinine (SCr) levels and estimated glomerular filtration rate were assessed at baseline and 2 to 5 days after receiving medications. The primary outcome was a postdose SCr increase > or = 0.5 mg/dL (44.2 micromol/L) over baseline. Secondary outcomes were a postdose SCr increase > or = 25%, a postdose estimated glomerular filtration rate decrease of > or = 25%, and the mean peak change in SCr. In 414 patients, contrast volume, presence of diabetes mellitus, use of N-acetylcysteine, mean baseline SCr, and estimated glomerular filtration rate were comparable in the 2 groups. SCr increases > or = 0.5 mg/dL occurred in 4.4% (9 of 204 patients) after iopamidol and 6.7% (14 of 210 patients) after iodixanol (P=0.39), whereas rates of SCr increases > or = 25% were 9.8% and 12.4%, respectively (P=0.44). In patients with diabetes, SCr increases > or = 0.5 mg/dL were 5.1% (4 of 78 patients) with iopamidol and 13.0% (12 of 92 patients) with iodixanol (P=0.11), whereas SCr increases > or = 25% were 10.3% and 15.2%, respectively (P=0.37). Mean post-SCr increases were significantly less with iopamidol (all patients: 0.07 versus 0.12 mg/dL, 6.2 versus 10.6 micromol/L, P=0.03; patients with diabetes: 0.07 versus 0.16 mg/dL, 6.2 versus 14.1 micromol/L, P=0.01). CONCLUSIONS: The rate of contrast-induced nephropathy, defined by multiple end points, is not statistically different after the intraarterial administration of iopamidol or iodixanol to high-risk patients, with or without diabetes mellitus. Any true difference between the agents is small and not likely to be clinically significant.

Pioglitazone increases adiponectin levels in nondiabetic patients with coronary artery disease.

OBJECTIVES: Hypoadiponectinemia is associated with coronary artery disease (CAD). Pioglitazone has been shown to increase levels of adiponectin in diabetic patients. We sought to assess whether administration of pioglitazone to patients with CAD and without diabetes would affect plasma adiponectin levels and endothelial function. METHODS: Seventeen patients with stable CAD and without evidence of diabetes were treated for 12 weeks with pioglitazone hydrochloride 30 mg daily. Adiponectin levels and endothelium-dependent flow-mediated vasodilation (ED-FMD) measurements were obtained pretreatment, posttreatment, and after a 12-week washout period. RESULTS: Treatment with pioglitazone increased adiponectin levels from an average of 10.6 to 21.1 microg/ml (P=0.001) and improved ED-FMD from 4.45 to 8.43% (P=0.001). CONCLUSION: Treatment with pioglitazone increased plasma adiponectin levels and improved ED-FMD in patients with stable CAD and no evidence of diabetes or insulin resistance.

Comparison of pioglitazone vs glimepiride on progression of coronary atherosclerosis in patients with type 2 diabetes: the PERISCOPE randomized controlled trial.

CONTEXT: No antidiabetic regimen has demonstrated the ability to reduce progression of coronary atherosclerosis. Commonly used oral glucose-lowering agents include sulfonylureas, which are insulin secretagogues, and thiazolidinediones, which are insulin sensitizers. OBJECTIVE: To compare the effects of an insulin sensitizer, pioglitazone, with an insulin secretagogue, glimepiride, on the progression of coronary atherosclerosis in patients with type 2 diabetes. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized, multicenter trial at 97 academic and community hospitals in North and South America (enrollment August 2003-March 2006) in 543 patients with coronary disease and type 2 diabetes. INTERVENTIONS: A total of 543 patients underwent coronary intravascular ultrasonography and were randomized to receive glimepiride, 1 to 4 mg, or pioglitazone, 15 to 45 mg, for 18 months with titration to maximum dosage, if tolerated. Atherosclerosis progression was measured by repeat intravascular ultrasonography examination in 360 patients at study completion. MAIN OUTCOME MEASURE: Change in percent atheroma volume (PAV) from baseline to study completion. RESULTS: Least squares mean PAV increased 0.73% (95% CI, 0.33% to 1.12%) with glimepiride and decreased 0.16% (95% CI, -0.57% to 0.25%) with pioglitazone(P = .002). An alternative analysis imputing values for noncompleters based on baseline characteristics showed an increase in PAV of 0.64% (95% CI, 0.23% to 1.05%) for glimepiride and a decrease of 0.06% (-0.47% to 0.35%) for pioglitazone (between-group P = .02). Mean (SD) baseline HbA(1c) levels were 7.4% (1.0%) in both groups and declined during treatment an average 0.55% (95% CI, -0.68% to -0.42%) with pioglitazone and 0.36% (95% CI, -0.48% to -0.24%) with glimepiride (between-group P = .03). In the pioglitazone group, compared with glimepiride, high-density lipoprotein levels increased 5.7 mg/dL (95% CI, 4.4 to 7.0 mg/dL; 16.0%) vs 0.9 mg/dL (95% CI, -0.3 to 2.1 mg/dL; 4.1%), and median triglyceride levels decreased 16.3 mg/dL (95% CI, -27.7 to -11.0 mg/dL; 15.3%) vs an increase of 3.3 mg/dL (95% CI, -10.7 to 11.7 mg/dL; 0.6%) (P < .001 for both comparisons). Median fasting insulin levels decreased with pioglitazone and increased with glimepiride (P < .001). Hypoglycemia was more common in the glimepiride group and edema, fractures, and decreased hemoglobin levels occurred more frequently in the pioglitazone group. CONCLUSION: In patients with type 2 diabetes and coronary artery disease, treatment with pioglitazone resulted in a significantly lower rate of progression of coronary atherosclerosis compared with glimepiride. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00225277.

Alterations of Blood Flow Through Arteries Following Atherectomy and the Impact on Pressure Variation and Velocity.

Simulations were made of the pressure and velocity fields throughout an artery before and after removal of plaque using orbital atherectomy plus adjunctive balloon angioplasty or stenting. The calculations were carried out with an unsteady computational fluid dynamic solver that allows the fluid to naturally transition to turbulence. The results of the atherectomy procedure leads to an increased flow through the stenotic zone with a coincident decrease in pressure drop across the stenosis. The measured effect of atherectomy and adjunctive treatment showed decrease the systolic pressure drop by a factor of 2.3. Waveforms obtained from a measurements were input into a numerical simulation of blood flow through geometry obtained from medical imaging. From the numerical simulations, a detailed investigation of the sources of pressure loss was obtained. It is found that the major sources of pressure drop are related to the acceleration of blood through heavily occluded cross sections and the imperfect flow recovery downstream. This finding suggests that targeting only the most occluded parts of a stenosis would benefit the hemodynamics. The calculated change in systolic pressure drop through the lesion was a factor of 2.4, in excellent agreement with the measured improvement. The systolic and cardiac-cycle-average pressure results were compared with measurements made in a multi-patient study treated with orbital atherectomy and adjunctive treatment. The agreements between the measured and calculated systolic pressure drop before and after the treatment were within 3%. This excellent agreement adds further confidence to the results. This research demonstrates the use of orbital atherectomy to facilitate balloon expansion to restore blood flow and how pressure measurements can be utilized to optimize revascularization of occluded peripheral vessels.

Physiologic Guidance of Infrainguinal Vascular Interventions Using the Pressure Wire.

OBJECTIVES: To assess the relationship between the resting (RG) and hyperemic (HG) translesional peripheral gradients, with the functional and anatomic parameters before and after an infrainguinal endovascular procedure. BACKGROUND: RGs and HGs are objective tools in defining the hemodynamic significance of an arterial stenosis. METHODS: In 25 subjects with infrainguinal arterial stenosis, RG and HG were measured via a pressure wire before and after angioplasty. Before and after the procedure, all subjects had an ankle-brachial index (ABI) and Duplex ultrasound evaluation, recording prelesion and in-lesion peak systolic velocity (PSV-L), and calculating a peak systolic velocity ratio (PSV-R). A Pearson R correlation coefficient was calculated. RESULTS: The mean age was 73 ± 12 years, 70% were men, median Rutherford class 3. At baseline and after angioplasty, mean ABI was 0.78 ± 0.2 and 0.99 ± 0.1, mean PSV-L was 459 ± 110 cm/s and 126 ± 35 cm/s, and mean PSV-R was 6.7 ± 4 and 1.2 ± 0.5, respectively. RG and HG significantly improved (P<.001) from baseline to after angioplasty (28.7 ± 20.5 mm Hg to 5 ± 13 mm Hg and 40.2 ± 21.4 mm Hg to 10 ± 13 mm Hg, respectively). RG before and after the procedure correlated well with ABI (r = -0.58; r = -0.41), PSV-L (r = 0.40; r = 0.52), and PSV-R (r = 0.46; r = 0.42). An improvement of 9 mm Hg in RG predicted a change of 0.1 in ABI. CONCLUSIONS: Improvement in RG during endovascular intervention in superficial femoral artery correlates well with the improvement in ABI, PSV-L, and PSV-R. A postprocedural decrease in RG of 9 mm HG predicts an improvement in ABI of 0.1.

Identification of vulnerable atherosclerotic plaques.

There has been great interest in the possibility of identifying plaques that might be the site of future acute coronary events. These plaques are termed vulnerable and the majority are lipid-rich with an abundance of inflammatory cells and a thin fibrous cap. Several techniques developed to identify these plaques are in various stages of development and in the near future, one might employ a strategy to potentially identify and therapeutically modify such lesions during percutaneous intervention to avoid future acute events. Although this approach of identifying the vulnerable plaque seems promising, there are significant potential limitations. The natural history of a vulnerable plaque is unknown and clinical trials utilizing this strategy of identification and therapeutic intervention are lacking. Moreover, in any given patient, multiple vulnerable plaques are likely to be present. This article reviews some of the techniques for identifying a vulnerable plaque and discusses the potential advantages and limitations of this strategy.

Percutaneous closure of secundum atrial septal defect in adults a single center experience with the amplatzer septal occluder.

Percutaneous closure of atrial septal defects (ASD) is increasingly performed in pediatric and adult patients. This study reports a single-center experience with the use of the Amplatzer Septal Occluder for percutaneous ASD closure in adults. One hundred and seventeen consecutive patients were prospectively included in the database. The procedure was successful in 106 patients (90.6%). The mean age was 50 years. Eighty-four percent of the patients had a Qp:Qs > 1.5. Other indications included a history of thromboembolism, decreased exercise tolerance, atrial arrhythmias, evidence of pulmonary hypertension or right heart overload. Mean procedure time was 44 minutes, and mean fluoroscopy time was 13 minutes. The mean defect diameter was 17.2 mm (range, 5 30 mm). There was no residual shunting at the end of the procedure in 75% of the patients. Shunting was minimal in all but 2 of the remaining 25 patients (1.8%). No major complications were observed at a mean follow-up of 19 months. Patients in whom the procedure failed had larger defects (mean, 25.0 mm versus 18.3 mm; p < 0.001), larger right ventricles (44.1 mm versus 38.2 mm; p = 0.03) and more significant shunting (Qp:Qs, 3.5 versus 2.1; p < 0.001). New York Heart Association functional class improved in all but 1 patient. Percutaneous ASD closure using ASO is safe and mid-term results compare favorably with those reported with surgical ASD closure. It can therefore be recommended as the first line of treatment in adult patients with secundum ASD.

Orbital atherectomy: device evolution and clinical data.

A number of atherectomy devices were developed in the last few years. Among them, the DiamondBack 360° Peripheral Orbital Atherectomy System (Cardiovascular Systems, Inc) was specifically designed to work in severely calcified plaque. This article reviews the history, mechanism of action, evolution, clinical data, and future applications of this particular atherectomy device.

Optimal techniques with the Diamondback 360° System achieve effective results for the treatment of peripheral arterial disease.

The Diamondback 360® Orbital PAD System (DB360) is a novel orbital atherectomy system for the treatment of calcified lower extremity lesions associated with peripheral arterial disease (PAD). This percutaneous, endovascular system incorporates the use of centrifugal force and differential sanding to modify plaque morphologies. The mechanism of differential sanding discriminates between compliant arterial tissue and diseased fibro-calcific or calcific plaque. An eccentrically mounted diamond-coated crown orbits at high speeds and removes a thin layer of calcific plaque with each pass of the crown. The crown creates a more concentric, smooth vessel lumen with increased diameter, increased lesion compliance and improved blood flow while protecting the vessel media. As a result, the risk for post-procedure thrombus formation and potential for restenosis may be reduced. The risk of intra-procedural events (slow flow, hemolysis, spasm and pain) may be reduced due to the design of this orbital sanding system along with proper technique. Extensive benchtop, in vivo, and clinical testing has confirmed these results and is presented within this paper. In addition, guidelines for selecting the most appropriate crown size and type (solid versus classic) and step-by-step procedural technique and pharmacology information are presented. The DB360 System provides a safe, efficacious, and cost-effective endovascular method for PAD treatment. Careful understanding of procedural methods, use of pharmacological drugs, and understanding of device operation contributes to improved treatment success.