Incidence and Predictors of Acute Coronary Syndrome in Patients on Maintenance Hemodialysis: A Prospective Cohort Study.

Background: Cardiovascular diseases are the leading cause of death among patients on hemodialysis, with approximately 40% of the cardiovascular deaths linked to acute coronary syndrome. We aimed to investigate the incidence and risk factors of acute coronary syndrome in patients undergoing hemodialysis. Methods: Patients undergoing hemodialysis were prospectively enrolled from January 2018. Data regarding hospitalization due to acute coronary syndrome were collected at 3-month intervals through December 31, 2021. Cox regression model was used to estimate the association between baseline factors and incident acute coronary syndrome during follow-up. Results: Patients' mean age was 66 years, 48% were men, and 16% had a history of coronary artery disease at enrolment. Over a median follow-up of 1,187 days, 85 patients were hospitalized due to acute coronary syndrome. Left main or triple vessel disease was identified in 67 patients. Risk factors associated with incident acute coronary syndrome included aging, male sex, smoking, low diastolic blood pressure, and baseline comorbidities, in addition to dialysis factors including low urea clearance, central venous catheter use, and history of dialysis access dysfunction. After multivariate analysis, age, diabetes, hyperlipidemia, smoking, and frequent interventions for vascular access remained significant risk factors. Conclusions: A high acute coronary syndrome incidence was observed in our cohort, with traditional risk factors playing a consistent role with that in the general population. A history of frequent dialysis access dysfunction was also associated with incident acute coronary syndrome.

A Randomised Trial Comparing Drug Coated Balloons and Conventional Balloons for the Treatment of Stent Graft Stenosis in Dialysis Vascular Access.

OBJECTIVE: Previous studies on arteriovenous fistulas have demonstrated the potential benefit of drug coated balloons (DCBs) in maintaining the patency of dialysis access. However, stenoses involving stent grafts were excluded from these studies. Therefore, the aim was to evaluate the effectiveness of DCBs in treating stent graft stenosis. METHODS: This was a prospective, single blinded, randomised controlled study. From March 2017 to April 2021, 40 patients with dysfunctional vascular access owing to stent graft stenosis were randomised to treatment with a DCB or conventional balloon. Clinical follow up was scheduled at one, three, and six months, and angiographic follow up was performed six months after the intervention. The primary outcome was angiographic late luminal loss at six months, and secondary outcomes included target lesion and access circuit primary patency at six months. RESULTS: Thirty-six participants completed follow up angiography. The DCB group had a superior mean late luminal loss at six months compared with the control group (1.82 mm ± 1.83 mm vs. 3.63 mm ± 1.08 mm, respectively, p = .001). All 40 patients completed clinical follow up. The DCB group had a superior six month target lesion primary patency compared with the control group [hazard ratio (HR) 0.23, 95% confidence interval (CI) 0.07 - 0.71; p = .005). Additionally, the DCB group had a numerically higher six month access circuit primary patency rate than the control group, although the difference was not statistically significant (HR 0.54, 95% CI 0.26 - 1.11, p = .095). CONCLUSION: Conventional balloon angioplasty is not durable in stent graft stenosis treatment. Treatment with DCBs provides less angiographic late luminal loss and potentially superior primary patency of the target lesion than treatment with conventional balloons. [ClinicalTrials ID: NCT03360279.].

Association of Frailty With Thrombosis of Hemodialysis Vascular Access: A Prospective Taiwanese Cohort Study.

RATIONALE & OBJECTIVE: Frailty, a multidimensional construct, has been associated with poor outcomes in patients receiving maintenance dialysis. This study assessed the association of frailty with dialysis vascular access patency. STUDY DESIGN: Multicenter prospective cohort study. SETTING & PARTICIPANTS: 761 prevalent patients receiving hemodialysis at 9 centers in Taiwan as of January 2018. EXPOSURE: Performance-based frailty was defined as 3 of the following: unintentional weight loss, weakness, exhaustion, low physical activity, and slow gait speed. Patients were categorized as prefrail if they had 1 or 2 of these characteristics. OUTCOME: Rate of and time to dialysis access thrombosis. Data regarding vascular access events were collected for 30 months after enrollment through December 31, 2020. ANALYTICAL APPROACH: Logistic regression analysis was used to estimate the association of clinical characteristics with frailty. Cox proportional hazards regression analysis was used to estimate the association of frailty with vascular access thrombosis adjusted for known clinical risk factors. RESULTS: The patients' mean age was 66 years, 46% were female, 18% had synthetic graft accesses, and 82% arteriovenous fistulas. Overall, 31% were frail, 35% were prefrail, and 34% were not frail. The frailty phenotype was associated with age, female sex, low body mass index, diabetes mellitus, and prior stroke. During a median follow-up of 731 days, 161 patients (21%) had access thrombosis events (not frail, 14%; prefrail, 20%; frail, 30%; P < 0.001). Frail patients had a higher risk of vascular access thrombosis than nonfrail patients (HR, 2.31 [95% CI, 1.55-3.39], P < 0.001). After multivariable adjustment for age and comorbidities, frailty remained significantly associated with access thrombosis for both fistulas and grafts. LIMITATIONS: Limited generalizability and potential residual confounding. CONCLUSIONS: Frailty is associated with an increased risk of vascular access thrombosis. These findings highlight the risks of access failure experienced by frail patients receiving hemodialysis.

A randomized controlled trial of drug-coated balloon angioplasty in venous anastomotic stenosis of dialysis arteriovenous grafts.

OBJECTIVE: Paclitaxel-coated balloons are used to reduce neointimal hyperplasia in native arteriovenous (AV) fistulas. However, no study specifically evaluated their effect on venous anastomotic stenosis of dialysis grafts. We aimed to compare the efficacy of angioplasty with drug-coated balloons (DCBs) and angioplasty with conventional balloons (CBs) for venous anastomotic stenosis in dysfunctional AV grafts. METHODS: In this investigator-initiated, single-center, single-blinded, prospective randomized controlled trial, we randomly assigned 44 patients who had venous anastomotic stenosis to undergo angioplasty with DCBs (n = 22) or CBs (n = 22) from July 2015 to August 2018. Access function was observed per the hemodialysis center's protocols; ancillary angiographic follow-up was performed every 2 months for 1 year after the interventions. The primary end point was target lesion primary patency at 6 months. Secondary outcomes included anatomic and clinical success after angioplasty, circuit primary patency at 6 months and 1 year, and target lesion primary patency at 1 year. RESULTS: At 6 months, target lesion primary patency in the DCB group was significantly greater than that in the CB group (41% vs 9%; hazard ratio [HR], 0.393; 95% confidence interval [CI], 0.194-0.795; P = .006), as was the primary patency of the entire access circuit (36% vs 9%; HR, 0.436; 95% CI, 0.218-0.870; P = .013). At 1 year, the target lesion primary patency in the DCB group remained greater than that in the CB group (23% vs 9%; HR, 0.477; 95% CI, 0.243-0.933; P = .019) but not the primary patency of the access circuit (14% vs 9%; HR, 0.552; 95% CI, 0.288-1.059; P = .056). No difference in anatomic or clinical success was observed; no major complications were noted. CONCLUSIONS: Angioplasty with DCBs showed a modest improvement in primary patency of venous anastomotic stenosis and all dialysis AV grafts at 6 months. The short-term benefit was not durable to 1 year, and reinterventions were eventually needed.

Dimethylarginine Dimethylaminohydrolase 1 Polymorphisms and Venous Intimal Hyperplasia in Hemodialysis Patients.

BACKGROUND: After angioplasty, veins are more prone to intimal hyperplasia than arteries. Veins tend to produce less nitric oxide (NO), which could lead to endothelial dysfunction. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase and contributes to cardiovascular disease. In humans, dimethylarginine dimethylaminohydrolase 1 (DDAH1) is the major enzyme for ADMA degradation. In this study, we aim to determine whether venous intimal hyperplasia in hemodialysis (HD) vascular access is influenced by common polymorphisms in the DDAH1 genes. METHODS: This is a prospective observational cohort study. A total of 473 HD patients referred for the angioplasty of vascular access were enrolled. There were 190 arteriovenous grafts (AVG) and 283 arteriovenous fistulas (AVF). The follow-up lasted for 2 years after the interventions. Seven single nucleotide polymorphisms (SNPs) in DDAH1 were genotyped and ADMA were measured at baseline. The primary outcome was restenosis after angioplasty. RESULTS: Among the 7 SNPs, plasma ADMA levels were significantly different in DDAH1 rs233112 (GA + GG vs. AA, 0.86 ± 0.23 vs. 0.82 ± 0.19 µM, p = 0.03) and rs1498373 (CT + TT vs. CC, 0.87 ± 0.23 vs. 0.82 ± 0.20 µM, p = 0.02) genotypes. The AVF group with GG + GA genotype of rs233112 and CT + TT genotype of rs1498373 had higher risks of early restenosis at 3 months. In the AVG group, only GG + GA genotype of rs233112 was associated with early restenosis. A combined analysis of AVG and AVF groups showed that patients with rs233112 GA + GG genotype and rs1498373 CT + TT genotype had higher risks of early restenosis (both p < 0.001). The multivariate analysis results showed that the association of these genotypes with early restenosis is independent of clinical, access, or biochemical factors. CONCLUSIONS: Our findings suggest that certain DDAH1 polymorphisms modulate circulating ADMA levels and are associated with venous intimal hyperplasia.

Timely thrombectomy can improve patency of hemodialysis arteriovenous fistulas.

OBJECTIVE: The urgency with which salvage of thrombosed vascular accesses for dialysis should be attempted remains unknown. We examined the effect of a timely thrombectomy approach on vascular access outcomes for dialysis. METHODS: A before-and-after study was conducted with patients on hemodialysis who had undergone endovascular thrombectomy. A timely thrombectomy initiative (ie, salvage within 24 hours of thrombosis diagnosis) was started in July 2015 at our institution. Data about thrombectomy procedures, performed within 1 year before and after the initiative was introduced, were abstracted from an electronic database. Immediate outcomes and patency outcomes were compared between the preinitiative (control) and postinitiative (intervention) groups. RESULTS: During the study period, 329 patients were enrolled, including 165 cases before and 164 cases after the initiative. The intervention group had more thrombectomy procedures performed within 24 hours (93% vs 55%; P < .01) and within 48 hours (97% vs 79%; P < .01) than the control group. No between-group differences in procedural success or clinical success rates were found. At 3 months, the intervention group had a higher postintervention primary patency rate than the control group, although this did not reach statistical significance (58% vs 48%; P = .06). After stratification into native or graft accesses, the patency benefit was observed in the native access group (68% vs 50%; P = .03) but not in the graft access group (50% vs 46%; P = .65). After adjusting for potential confounders, timely thrombectomy remained an independent predictor of postintervention primary patency (hazard ratio, 0.449; 95% confidence interval, 0.224-0.900; P = .02) for native dialysis accesses. CONCLUSIONS: Our results suggest that a timely thrombectomy approach, in which salvage is attempted within 24 hours of thrombosis diagnosis, improves postintervention primary patency of native but not graft accesses for dialysis.

Recruiting an Acute Coronary Team to Perform Emergent Mechanical Thrombectomy in Acute Ischemic Stroke Patients: A Successful Case and Team Model in a Local Hospital.

Stroke treatment has entered a new era after the publication of multiple randomized trials involving the use of a stent retriever since 2015. In Taiwan, the demand for interventional neuroradiologists to perform mechanical thrombectomy is high. For this reason, providing this standard care requires reshaping of the care model. Here, we report our experience in recruiting an acute coronary care team to perform emergent mechanical thrombectomy, which is essential in a patient with acute ischemic stroke.

Deterioration of Deceleration Capacity of Heart Rate is Associated with Left Ventricular Hypertrophy in End-Stage Renal Disease Population.

BACKGROUND: Left ventricular hypertrophy (LVH) is prevalent in patients with end-stage renal disease (ESRD), and may be secondary to arterial stiffness and volume overload. It is unclear whether LVH is caused by autonomic nerve dysregulation (AND), a frequent condition in patients with ESRD that is characterized by sympathetic hyperactivity and vagal withdrawal. We hypothesized that AND estimated by heart rate variability (HRV) may be associated with LVH in patients with ESRD. METHODS: We prospectively enrolled patients with ESRD undergoing hemodialysis. Cardiac function and LVH were assessed using echocardiography according to the recommendations of the American Society of Echocardiography. Holter recordings were used to quantify HRV and deceleration capacity (DC). Dataon comorbidities and medications, and serum markers were obtained. Logistic regression analysis was performed. RESULTS: Among the 281 included patients, 63% had LVH. The patients with LVH were older, had more comorbidities and advanced diastolic dysfunction than those without LVH. The root mean square of successive differences (rMSSD) (9.10 ± 5.44 versus 13.25 ± 8.61; p = 0.004) and DC (2.08 ± 1.90 versus 3.89 ± 1.45; p = 0.021) were lower in the patients with LVH than that in those without LVH. Multivariate regression analysis showed that hypertension, asymmetrical dimethylarginine (ADMA), advanced diastolic dysfunction grade, rMSSD, and DC were independently associated with LVH. Among these variables, DC and ADMA showed the highest diagnostic value for LVH with areas under curves of 0.701 and 0.751, respectively. CONCLUSIONS: AND is independently associated with LVH in patients with ESRD.

Catheter-directed therapy for acute renal vein thrombosis in systemic lupus erythematosus: A case report.

We report our experience using catheter-directed thrombectomy/thrombolysis (CDT) to treat a patient with acute renal vein thrombosis (RVT) associated with systemic lupus erythematosus (SLE). A 34-year-old woman presented with persistent left flank pain, and a renal ultrasonography examination revealed an enlarged left kidney. Contrast-enhanced computed tomography confirmed the presence of acute left RVT. Because medical treatment failed to relieve her pain and the renal function was deteriorating, we attempted to salvage the occluded left renal vein using an endovascular approach. The pain was completely relieved after a CDT and an overnight urokinase infusion. A follow-up computed tomography examination revealed the complete resolution of the thrombus. The creatinine level returned to normal (1.7-0.4 mg/dL), along with contrast enhancement in the left kidney, and this suggested the preservation of renal function. To our knowledge, this is the first report utilizing CDT to treat SLE-associated RVT. When the renal function is deteriorating, CDT is worth considering for RVT if conventional medical treatment has failed. © 2016 Wiley Periodicals, Inc.

Deficiency of circulating progenitor cells associated with vascular thrombosis of hemodialysis patients.

Background: Hemodialysis (HD) patients have an increased risk of thrombosis. Endothelial progenitor cells (EPCs), which function in vascular repair, are deficient in HD patients. Nonetheless, the relationship between EPC deficiency and thrombosis in HD patients is unknown. Methods: From January 2010 to December 2012, circulating levels of EPCs that were positive for CD34 and kinase insert domain receptor (KDR) were measured in 269 HD patients. Patients received prospective follow-ups at 6-month intervals until May 2015. The primary outcome was the composite of HD access thrombosis and systemic vascular thrombosis. Results: There were 141 thrombotic events, 50 systemic vascular thrombotic events and 116 HD access thrombotic events. We found significantly negative associations between CD34 + KDR + tertile and overall thrombotic events (low: 61%; middle: 56%; high: 40%; P = 0.02), systemic vascular thrombotic events (low: 27%; middle: 18%; high: 10%; P = 0.03) and HD access thrombotic events (low: 52%; middle: 46%; high: 36%; P = 0.02). Univariate analysis indicated that systemic vascular thrombotic events were positively associated with age, diabetes, dyslipidemia, vascular disease history, urea clearance, albumin and C-reactive protein (CRP), and negatively associated with CD34 + KDR + cell count. HD access thrombosis was positively associated with vascular disease history and CRP, and negatively associated with CD34 + KDR + cell count. Multivariate analysis indicated that a low CD34 + KDR + cell count was an independent risk factor for both types of thrombosis. Conclusions: Our study of a population of HD patients showed that a low level of circulating EPCs is associated with thrombosis.

Serum Indoxyl Sulfate Associates with Postangioplasty Thrombosis of Dialysis Grafts.

Hemodialysis vascular accesses are prone to recurrent stenosis and thrombosis after endovascular interventions.In vitro data suggest that indoxyl sulfate, a protein-bound uremic toxin, may induce vascular dysfunction and thrombosis. However, there is no clinical evidence regarding the role of indoxyl sulfate in hemodialysis vascular access. From January 2010 to June 2013, we prospectively enrolled patients undergoing angioplasty for dialysis access dysfunction. Patients were stratified into tertiles by baseline serum indoxyl sulfate levels. Study participants received clinical follow-up at 6-month intervals until June 2014. Primary end points were restenosis, thrombosis, and failure of vascular access. Median follow-up duration was 32 months. Of the 306 patients enrolled, 262 (86%) had symptomatic restenosis, 153 (50%) had access thrombosis, and 25 (8%) had access failure. In patients with graft access, free indoxyl sulfate tertiles showed a negative association with thrombosis-free patency (thrombosis-free patency rates of 54%, 38%, and 26% for low, middle, and high tertiles, respectively;P=0.001). Patients with graft thrombosis had higher free and total indoxyl sulfate levels. Using multivariate Cox regression analysis, graft thrombosis was independently predicted by absolute levels of free indoxyl sulfate (hazard ratio=1.14;P=0.01) and free indoxyl sulfate tertiles (high versus low, hazard ratio=2.41;P=0.001). Results of this study provide translational evidence that serum indoxyl sulfate is a novel risk factor for dialysis graft thrombosis after endovascular interventions.

Deficiency of Endothelial Progenitor Cells Associates with Graft Thrombosis in Patients Undergoing Endovascular Therapy of Dysfunctional Dialysis Grafts.

BACKGROUND: The deficiency of endothelial progenitor cells has been demonstrated to be associated with cardiovascular events in patients undergoing dialysis. However, their correlation with dialysis graft outcomes remains unknown. The objective of this study was to investigate the relationship between circulating endothelial progenitor cells and dialysis graft outcomes. METHODS: After excluding 14 patients with acute coronary syndrome, decompensated heart failure or graft thrombosis in the prior three months, a total of 120 patients undergoing dialysis who underwent endovascular therapy of dysfunctional dialysis grafts were prospectively enrolled. Blood was sampled from study subjects in the morning of a mid-week non-dialysis day. Surface makers of CD34, KDR, and CD133 were used in combination to determine the number of circulating endothelial progenitor cells. All participants were prospectively followed until June 2013. RESULTS: The median follow-up duration was 13 months, within which 62 patients experienced at least one episode of graft thrombosis. Patients with graft thrombosis had lower CD34+KDR+ cell counts compared with patients without graft thrombosis (median 4.5 vs. 8 per 105 mononuclear cells, p = 0.02). Kaplan-Meier analysis demonstrated thrombosis-free survival was lower in the low CD34+KDR+ cell count group (30%) than in the high CD34+KDR+ cell count group (61%; p = 0.007). Univariate analysis showed diabetes, high sensitive C-reactive protein, lesion length and CD34+KDR+ cell counts associated with graft thrombosis. Multivariate analyses confirmed an independent association between low CD34+KDR+ cell counts and graft thrombosis (hazard ratio, 2.52; confidence interval, 1.43-4.44; p = 0.001). CONCLUSIONS: Our study demonstrated an independent association between low circulating endothelial progenitor cell counts and dialysis graft thrombosis.

Primary Endovascular Intervention for Acute Mesenteric Ischemia Performed by Interventional Cardiologists - A Single Center Experience.

The current standard care for acute mesenteric ischemia (AMEI) involves urgent revascularization and resection of the necrotic bowel. Since 2012, we have used an AMEI protocol of our own design, which focused on early treatment and allowed interventional cardiologists to become involved when interventional radiologist was not available. A total of 8 patients were treated, and two interventional cardiologists performed all the stenting procedures. The procedure success rate was 100% in patients with non-calcified lesions (6/8). The 30-day survival rate was 100% in patients with angiographic success, and was 0% in patients with failed procedure. In two patients with total occlusion of the superior mesenteric artery, laparotomy was avoided when interventions were successful and completed within six hours of protocol activation. Four surviving patients were discharged after short intensive care unit stays (less than 48 hours); these patients returned to and remained at home throughout their 90-day follow-up. The overall procedure success rate and 30-day survival rate were both 75%. There was no access site or intervention-related complications. Using our protocol, we believe that primary endovascular treatment for AMEI is feasible. In geographic regions where healthcare resources are lacking, a time-efficient strategy adopted by interventional cardiologists should be considered for the purpose of saving lives and possibly even avoiding open laparotomy.

Circulating Progenitor Cells Affect Thrombosis of Dialysis Arteriovenous Fistulas.

BACKGROUND: Arteriovenous fistula (AVF) thrombosis is a relevant cause of morbidity in hemodialysis (HD) patients. The number of circulating endothelial progenitor cells (EPCs) has been identified as a surrogate marker for vascular repair and health. Deficiency of EPCs has been demonstrated in dialysis patients to be associated with vascular events. Nonetheless, their role in thrombosis of AVFs remains unknown. METHODS: From January 2010 to May 2013, 147 HD patients with dysfunctional AVFs were enrolled. Surface makers including CD34, KDR and CD133 were used in combination to determine the number of circulating EPCs. All participants were prospectively followed at 6-month interval until December 2015. The primary outcome was thrombosis of dialysis AVFs. RESULTS: The median follow-up was 47 months, within which 42 patients experienced at least one episode of AVF thrombosis. Patients with AVF thrombosis had lower CD34+KDR+ cell counts compared with patients without thrombosis (median 5 vs. 13 per 150,000 mononuclear cells, p < 0.001). Kaplan-Meier analysis demonstrated an inverse relationship between CD34+KDR+ cell count tertiles and thrombosis-free patency (59, 69 and 86% for low, middle and high tertiles; p = 0.02). Using Cox regression analysis, AVF thrombosis was predicted by baseline CD34+KDR+ cell counts (hazards ratio (HR) 0.963, 95% CI 0.928-1.000, p = 0.05) and tertiles (high vs. low, HR 3.266, 95% CI 1.380-7.728, p < 0.01). In multivariate analysis, only CD34+KDR+ cell tertiles, C-reactive protein and lesion length remained independent predictors for thrombosis. CONCLUSION: Our study demonstrated an independently reverse association between circulating EPCs and thrombosis of dialysis AVFs. Further studies are warranted to ascertain whether EPCs serve as a marker or a therapeutic target for AVF thrombosis.

Pulmonary Hypertension in Hemodialysis Patients Following Repeated Endovascular Thrombectomy.

BACKGROUND: The prevalence of pulmonary hypertension is unusually high in Taiwanese patients with end-stage renal disease. Thrombosis of hemodialysis grafts is common and pulmonary embolism has been reported after endovascular thrombectomy. The aim of this study was to evaluate the relationship between pulmonary hypertension and endovascular thrombectomy of hemodialysis grafts. METHODS: One hundred and ten patients on hemodialysis via arteriovenous grafts were enrolled in our study. The mean pulmonary artery pressure (PAP) was measured by right heart catheterization. Clinical information was collected by review of medical records. Comorbid cardiopulmonary disease was evaluated by echocardiography and chest X-ray. The history of patient vascular access thrombosis was reviewed from database, hemodialysis records, and interviews with staff at hemodialysis centers. RESULTS: Fifty-two participants (47%) had pulmonary hypertension diagnosed by right heart catheterization. There was no difference in the number of thrombectomy procedures between patients with and without pulmonary hypertension. Based on multivariate analysis, the number of prior endovascular thrombectomy procedures did not correlate with mean PAP (F-value = 1.10, p = 0.30) nor was it associated with pulmonary hypertension (odds ratio = 0.92, p = 0.17). CONCLUSIONS: Prior endovascular arteriovenous graft thrombectomies were not associated with pulmonary hypertension or increased mean PAP in end-stage renal disease patients on maintenance hemodialysis.

Feasibility and Safety of Coronary Procedures via an Arteriovenous Graft Approach in Patients on Maintenance Hemodialysis.

BACKGROUND: Traditionally, a radial or brachial arterial approach is unadvisable in hemodialysis patients. Consequently, coronary angiography or angioplasty is usually performed via a femoral artery approach in these patients, who carry a higher risk of vascular access complications. In hemodialysis patients, arteriovenous grafts (AVG) are created for repeated punctures; however, the feasibility and safety of a trans-AVG approach for coronary angiography or angioplasty remains unclear. METHODS: In our institution, cardiac catheterizations were attempted via AV grafts in hemodialysis patients with a U-shaped forearm AVG. We retrospectively identified coronary angiography or angioplasty procedures in hemodialysis patients from a computer-based database in our hospital. The procedure details and outcomes were obtained from review of the clinical, angiographic and hemodialysis records. RESULTS: From 2008 to 2013, 167 procedures in hemodialysis patients were identified from 2866 diagnostic or interventional coronary procedures in our institution. Out of these, 24 procedures in 17 patients were performed via a trans-AVG approach. In all AVG procedures, a 6F 16-cm or 7F 10-cm sheath was placed from the AVG into the brachial artery. All diagnostic procedures were successfully performed. In 14 procedures, the patients also underwent angioplasty and all of the angioplasty procedures were successful. There was no arterial spasm, arterial dissection, puncture site hematoma, or acute thrombosis of the AVG during or after the procedures. CONCLUSIONS: A trans-AVG approach appears to be a feasible and safe route for coronary angiography or angioplasty in hemodialysis patients with a U-shaped forearm AVG. However, further studies with a larger patient number are necessary. KEY WORDS: Arteriovenous graft; Hemodialysis; Percutaneous coronary intervention.

Impact on pulmonary arterial pressures after repeated endovascular thrombectomy of dialysis grafts: a prospective follow-up study.

PURPOSE: Vascular access thrombosis is a common complication of arteriovenous dialysis grafts that results in silent pulmonary embolism (PE) in a substantial proportion of patients. However, the impact of repeated PE on the pulmonary vasculature remains unclear. MATERIALS AND METHODS: From January 2010 to April 2012, 110 patients undergoing maintenance hemodialysis via arteriovenous grafts were recruited. Hemodynamic assessments, including transthoracic echocardiography and right heart catheterization, were performed at baseline and after 1 year to evaluate the changes in pulmonary artery (PA) pressures and heart function. RESULTS: Fifty-two patients completed the follow-up hemodynamic assessment at a median duration of 535 days and had at least one endovascular thrombectomy procedure (median of seven). There was no significant difference in mean PA pressures between baseline and the end of follow-up (23.1 mm Hg ± 6.8 vs 21.6 mm Hg ± 6.1; P = .16). The change in mean PA pressure did not correlate with the number of thrombectomy procedures in the overall cohort (r = -0.02, P = .89) or in the subgroup with cardiopulmonary disease (r = -0.30, P = .14). The changes of mean PA pressure were not associated with number of thrombectomy procedures (ß = -0.03, P = .89). CONCLUSIONS: Repeated endovascular thrombectomy procedures are not related to changes in PA pressure in the short term. The present results support the safety of endovascular thrombectomy in the pulmonary vasculature.