Effect of Rivaroxaban and Clopidogrel Combination Therapy on In-Stent Responses After Everolimus-Eluting Stent Implantation in a Porcine Coronary Model.

AIM: According to recent clinical trials, a combination of direct oral anticoagulants with antiplatelet drugs is often recommended for atrial fibrillation patients who receive drug-eluting stents (DESs). Although the optimal combination comprises direct factor Xa inhibitors and a P2Y12 receptor antagonist (or aspirin), their influence on vascular responses to DESs remains unclear. METHODS: Pigs were given either aspirin and clopidogrel (dual antiplatelet therapy [DAPT] group), aspirin and rivaroxaban (AR group), or clopidogrel and rivaroxaban (CR group), followed by everolimus-eluting stent (Promus Element) implantation into the coronary artery. Stented coronary arteries were evaluated via intravascular optical coherence tomography (OCT) and histological analysis at 1 and 3 months. RESULTS: OCT revealed lower neointimal thickness in the DAPT group and comparable thickness among all groups at 1 and 3 months, respectively. Histological analyses revealed comparable neointimal area among all groups and the smallest neointimal area in the CR group at 1 and 3 months, respectively. In the DAPT and AR groups, the neointima continued to grow from 1 to 3 months. A shortened time course for neointima growth was observed in the CR group, with rapid growth within a month (maintained for 3 months). A higher incidence of in-stent thrombi was observed in the AR group at 1 month; no thrombi were found in either group at 3 months. More smooth muscle cells with contractile features were found in the CR group at both 1 and 3 months. CONCLUSIONS: Our results proved the noninferiority of the combination of rivaroxaban with an antiplatelet drug, particularly the dual therapy using rivaroxaban and clopidogrel, compared to DAPT after DES implantation.

Intensive versus moderate atorvastatin therapy and one-year graft patency after CABG: Rationale and design of the ACTIVE (Aggressive Cholesterol Therapy to Inhibit Vein Graft Events) randomized controlled trial (NCT01528709).

RATIONALE: Saphenous vein graft disease remains a major limitation of coronary artery bypass graft surgery (CABG). Statin therapy inhibits the development of vein graft disease and improves outcomes after CABG. However, it is unclear whether treatment with high-dose statins will further slow the process of vein graft disease and improve graft patency, as compared to conventional moderate doses. Therefore, the goal of this study will be to evaluate the efficacy of high-dose statin therapy versus moderate-dose statin therapy for the prevention of saphenous vein graft occlusion following CABG. STUDY DESIGN: The Aggressive Cholesterol Therapy to Inhibit Vein Graft Events (ACTIVE) trial is a multi-center double-blind randomized controlled trial enrolling patients who have undergone multi-vessel CABG with at least one saphenous vein graft. Patients will be randomized to receive either atorvastatin 80mg daily or atorvastatin 10mg daily for one year starting within 5days after surgery. The target enrollment is 100 patients in each arm (200 patients total). Lipid levels will be assessed every 3months. After one year, patients will undergo computed tomography (CT) coronary angiography to assess the incidence of vein graft occlusion and stenosis. CONCLUSION: This trial is the first prospective study to evaluate the impact of early postoperative high-dose statin therapy on graft patency after CABG. Should high-dose statin therapy reduce the incidence of postoperative graft occlusion, the results will add to the growing evidence supporting the role of high-intensity statins for modern lipid management after coronary surgical revascularization (ClinicalTrials.govNCT01528709).

The association of mineral metabolism with vascular access patency.

BACKGROUND: Declining kidney function leads to progressively dysregulated mineral homeostasis and contributes to vascular calcification and a pro-inflammatory milieu, both of which play a critical role in loss of dialysis vascular access patency. We designed this study to examine the relationship between markers of bone and mineral metabolism, vitamin D replacement medications, and vascular access outcomes. We hypothesized that higher levels of calcium, phosphorous, parathyroid hormone (PTH), and albumin are independently associated with vascular access patency and that vitamin D supplementation is associated with lower risk of access failure. METHODOLOGY: We abstracted data on 204 consecutive patients referred for angiographic evaluation of their permanent arteriovenous access over a 25-month period. We followed patients from the time of access salvage until subsequent referral for access failure. RESULTS: The incidence of vascular access failure did not differ by serum phosphorus, PTH, calcium, calcium-phosphorus product or albumin level. Patients receiving any vitamin D replacement therapy, however, had a lower incidence of access failure compared to those receiving no therapy. Those receiving vitamin D3 therapy with or without paricalcitol (Zemplar, Abbot Laboratories, Abbot Park, IL) or calcitriol had an adjusted HR = 0.18 compared to those receiving no vitamin D therapy. CONCLUSIONS: This study suggests a relationship between vitamin D3 usage and better vascular access patency, independent of the effect of vitamin D on PTH. Though this relationship needs more rigorous investigation prior to clinical application, the known differences in the pro- and anti-inflammatory effects of various vitamin D metabolites provide a potential mechanism for these clinical observations.

Rivaroxaban for the treatment of saphenous vein graft thrombosis.

Thrombus formafigtion plays a significant role in disease of saphenous vein bypass grafts. Use of oral anticoagulants has not been tested in treatment of thrombotic occlusion of saphenous vein graft (SVG) disease. Here we describe the use of the novel oral anticoagulant rivaroxaban in the treatment of occlusive SVG disease with intraluminal thrombus, leading to successful recanalization.

Percutaneous Coronary Intervention in Native Coronary Arteries Versus Bypass Grafts in Patients With Prior Coronary Artery Bypass Graft Surgery: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

OBJECTIVES: The aim of this study was to examine the frequency, associations, and outcomes of native coronary artery versus bypass graft percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass grafting (CABG) in the Veterans Affairs (VA) integrated health care system. BACKGROUND: Patients with prior CABG surgery often undergo PCI, but the association between PCI target vessel and short- and long-term outcomes has received limited study. METHODS: A national cohort of 11,118 veterans with prior CABG who underwent PCI between October 2005 and September 2013 at 67 VA hospitals was examined, and the outcomes of patients who underwent native coronary versus bypass graft PCI were compared. Logistic regression with generalized estimating equations was used to adjust for correlation between patients within hospitals. Cox regressions were modeled for each outcome to determine the variables with significant hazard ratios (HRs). RESULTS: During the study period, patients with prior CABG represented 18.5% of all patients undergoing PCI (11,118 of 60,171). The PCI target vessel was a native coronary artery in 73.4% and a bypass graft in 26.6%: 25.0% in a saphenous vein graft and 1.5% in an arterial graft. Compared with patients undergoing native coronary artery PCI, those undergoing bypass graft PCI had higher risk characteristics and more procedure-related complications. During a median follow-up period of 3.11 years, bypass graft PCI was associated with significantly higher mortality (adjusted HR: 1.30; 95% confidence interval: 1.18 to 1.42), myocardial infarction (adjusted HR: 1.61; 95% confidence interval: 1.43 to 1.82), and repeat revascularization (adjusted HR: 1.60; 95% confidence interval: 1.50 to 1.71). CONCLUSIONS: In a national cohort of veterans, almost three-quarters of PCIs performed in patients with prior CABG involved native coronary artery lesions. Compared with native coronary PCI, bypass graft PCI was significantly associated with higher incidence of short- and long-term major adverse events, including more than double the rate of in-hospital mortality.

Ultrasound-guided angioplasty of autogenous arteriovenous fistulas in the office setting.

OBJECTIVE: There has been an increasing awareness of the superiority of native arteriovenous fistulas (AVFs) over prosthetic grafts for dialysis access. Many AVFs fail to mature, however, and others develop stenosis while in use. There is growing experience in treating these patients in the interventional suite with percutaneous balloon angioplasty. These procedures, however, are expensive, uncomfortable, and inconvenient for patients and physicians, and involve exposure to radiation and intravenous contrast in patients who are often not on dialysis. This study reviews our experience with ultrasound-guided angioplasty of AVFs in the office setting. METHODS: A retrospective review was performed of all patients treated in our practice with ultrasound-guided AVF angioplasty, from May 2009 to April 2011. The need for intervention was determined by examination and duplex ultrasound. All patients referred to the practice with failing or nonmaturing AVFs were treated in the office under ultrasound guidance, unless a central venous stenosis was suspected. All procedures were performed with the patient under local anesthesia by a single surgeon, and preprocedure, periprocedure, and postprocedure ultrasounds were performed in a single vascular laboratory. RESULTS: There were 31 AVFs in 30 patients in the study. Fifty-five interventions were performed, 48 for AVFs failing to mature and seven for stenosis in functioning AFVs. The 90-day patency was 93%. The overall complication rate was 11%. Two patients had proximal stenosis that could not be crossed (one patient required surgical revision and one patient refused further treatment and thrombosed). There were four perifistular hematomas; three of these resulted in AFV thrombosis. No patients required hospitalization or urgent surgical intervention. Eighty-five percent of patients treated for AVF failing to mature achieved a functional fistula. CONCLUSIONS: AVF intervention can be performed safely and effectively under ultrasound guidance in the office setting and is a valuable tool in the management of dialysis access patients.

Radial artery angiographic string sign: clinical consequences and the role of pharmacologic therapy.

BACKGROUND: The radial artery is an increasingly important graft for coronary artery bypass surgery. Postoperative angiographic studies have shown that a proportion of radial grafts become diffusely narrowed but not occluded, or string signs. METHODS: Four hundred forty patients receiving a radial artery graft enrolled in a large clinical trial underwent postoperative angiography at 1 year. Angiograms were analyzed visually and quantitatively. A complete string sign was defined as diffuse narrowing along the full length of the graft, while a partial string sign was defined as segmental narrowing. Angiographic findings were correlated with medication compliance and clinical sequelae. RESULTS: Thirty-one patients (7.0 %) had radial artery graft string signs versus 4 patients (0.9%) with a saphenous vein graft string sign (p = 0.001). Complete string signs were present in 28 cases, and the mean diameter was 0.76 +/- 0.14 mm (mean +/- SD), whereas 3 cases had a partial string sign with a diameter of 0.89 +/- 0.14 mm. Fifteen radial arteries showed Thrombolysis in Myocardial Infarction Study (TIMI) 1 flow, 3 cases showed TIMI 2 flow, and 13 cases showed TIMI 3 flow. There was no difference in incidence of radial string sign between patients taking nifedipine versus diltiazem postoperatively. Multivariate analysis revealed the presence of radial artery string sign was closely related to the perioperative use of alpha-adrenergic agonists and target vessels stenosis less than 90%. Postoperative symptoms were associated with radial artery string signs with TIMI 1 flow (p = 0.0045). CONCLUSIONS: In the Radial Artery Patency Study, radial artery string sign was present in 7% of patients. Despite diffuse narrowing, 52% of grafts had TIMI 2 flow or better.

[Surgical management of dysfunctions of dialysis fistulas]. / Operatives Management bei Funktionsstörungen von Dialysefisteln.

Due to the superficial position of shunt vessels we do not use complicated equipment or diagnostic procedures in the morphological assessment of shunt insufficiency or shunt occlusion. Preoperatively, we merely conduct a clinical examination including inspection, pulse, palpation of the shunt veins and arteries with and without venous congestion, and shunt auscultation. Subsequently, we reoperate the shunt under local anesthesia, at which time the anastomosis is usually checked and repositioned. From January 1995 to May 1996, 539 shunt operations were performed in 371 patients, whereby 263 of these were reoperations. The reoperations were performed due to shunt occlusion (n = 144), shunt stenoses (n = 60), shunt aneurysms (n = 17), steal syndrome (n = 3), and rare complications such as hematoma, shunt infection, seroma, and other disturbances (n = 6) (32 patients were treated in other clinics after reoperation or the functional disturbance of the shunt was not recorded). Angiography was only conducted if the clinical examination did not provide enough information about the shunt problems, and so, preoperatively, only six angiographic examinations were conducted (stenosis, n = 3; aneurysm, n = 1; steal syndrome, n = 2). All reoperations, with only few exceptions (PTFE shunt), were conducted under local anesthesia. At reoperation, 184 new proximal shunts were made, 14 thrombectomies conducted, seven PTFE fistulas made, 13 shunts positioned on the opposite side, five shunts ligated, and eight various other operations performed (32 patients were given further treatment elsewhere or no treatment records were available). If during reoperation flow disturbances were suspected (arterial stenosis) or the blood was flowing towards center (proximal venous stenosis) angiography was performed intraoperatively to assess the condition of the vessels. The 4% rate of early occlusion using this procedure was very low. Only 21 patients had to have more than two reoperations. After 2 years 65% of the reoperated AV fistulas were still functional. Without further diagnostic procedures, we performed immediate, outpatient reoperation under local anesthesia, preferably positioning new proximal shunts so that dialysis could be conducted immediately using the existing dialysis shunt. Only if there were particularly complex functional shunt disturbances (steal syndrome, proximal venous flow disturbance, or arterial stenosis) did we employ other diagnostic procedures (angiography, DSA). With this approach the functional shunt disturbances could be eliminated quickly and effectively, which also minimized the cost and stress for the patient.