Platelet dysfunction and end-stage renal disease

Endovascular Treatment of Intracranial Aneurysms in Patients With Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Little is known about the outcome of endovascular treatment for intracranial aneurysms in patients with autosomal dominant polycystic kidney disease (ADPKD).

OBJECTIVE

To present clinical outcomes in terms of safety, effectiveness, and renal functions to assess contrast-induced nephropathy in endovascular coil embolization for intracranial aneurysms in ADPKD patients.

METHODS

Nineteen ADPKD patients (female:male, 15:4; mean age, 49.8 years; range, 20-67 years) had 26 aneurysms (mean size, 5.86 mm; range, 2.5-11.6 mm) and underwent 22 endovascular treatment sessions from 2001 to 2013. Four patients presented with ruptured aneurysms. Periprocedural complications, clinical outcomes with modified Rankin Scale scores, laboratory findings, and chronic kidney disease (CKD) stage before and after treatment were documented. Acute renal impairment was defined as serum creatinine (Cr) elevation by ≥ 0.5 mg/dL or 25% relative to baseline.

RESULTS

Symptomatic periprocedural complications developed after 1 endovascular procedure (1 of 22, 4.5%), and good clinical outcomes (modified Rankin Scale scores, 0-1) were achieved in 90% of patients (17 of 19). Overall, acute renal impairment occurred in 9.1% of treatment sessions (2 of 22). Acute renal impairment developed in 25% of high-risk patients (baseline Cr > 2.0 mg/dL) and 33.3% of baseline CKD stage 5 sessions but in none of the low-risk patients (baseline Cr ≤ 2.0 mg/dL) and in no CKD stage 1 to 4 sessions.

CONCLUSION

With appropriate management, coil embolization may be safe and effective for intracranial aneurysms in ADPKD. There is a concern about contrast-induced nephropathy in patients with CKD stage 5 or high serum Cr level (>2.0 mg/dL).

Comparison of Drug-Eluting and Bare Metal Stents in Patients With Chronic Kidney Disease: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Drug-eluting stents (DESs) and bare metal stents (BMSs) are both recommended to improve coronary revascularization and to treat coronary artery disease in patients with chronic kidney disease (CKD). However, the potential superiority of DESs over BMSs for reducing the incidence of long-term major adverse cardiovascular events and mortality in CKD patients has not been established, and the results remain controversial. We aimed to systematically assess and quantify the total weight of evidence regarding the use of DESs versus BMSs in CKD patients.

METHODS AND RESULTS

In this systematic review and conventional meta-analysis, electronic studies published in any language until May 20, 2016, were systematically searched through PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We included randomized controlled trials and observational studies comparing outcomes in CKD patients with DESs versus BMSs and extracted data in a standard form. Pooled odd ratios and 95% CIs were calculated using random- and fixed-effects models. Finally, 38 studies involving 123 396 patients were included. The use of DESs versus BMSs was associated with significant reductions in major adverse cardiovascular events (pooled odds ratio 0.75; 95% CI, 0.64-0.88; P<0.001), all-cause mortality (odds ratio 0.81; 95% CI, 0.73-0.90; P<0.001), myocardial infarction, target-lesion revascularization, and target-vessel revascularization. The superiority of DESs over BMSs for improving clinical outcomes was attenuated in randomized controlled trials.

CONCLUSIONS

The use of DESs significantly improves the above outcomes in CKD patients. Nevertheless, large-sized randomized controlled trials are necessary to determine the real effect on CKD patients and whether efficacy differs by type of DES.

Platelet aggregometry cannot identify uremic platelet dysfunction in heart failure patients prior to cardiac surgery

BACKGROUND

Patients with heart failure often have concomitant renal disease which can result in uremic platelet dysfunction. Determining whether uremia has affected platelets by platelet aggregometry can be challenging in these patients since they are often on antiplatelet medications. This study was undertaken to determine if platelet aggregation studies could identify heart failure patients at risk for uremic bleeding prior to cardiac surgery.

METHODS

Platelet aggregation studies from three groups were studied and compared: 17 heart failure patients with mild to moderate renal impairment, 17 heart failure patients without renal abnormalities and 17 healthy volunteers.

RESULTS

Platelet aggregation was severely impaired in both heart failure groups with and without renal abnormalities compared to healthy controls, and there were no significant differences in platelet aggregation in response to any of the agonists. There was a pan-decrease in platelet aggregation to all agonists in all heart failure patients.

CONCLUSION

Platelet aggregometry does not appear to be useful in measuring platelet dysfunction in heart failure patients with mild to moderate renal impairment.

Mitral valve replacement in a dialysis-dependent patient

Patients with end-stage renal disease have a higher risk of morbidity and mortality than those without end-stage renal disease in cardiovascular surgery. Poor outcomes are especially found in patients who undergo valve surgery. We report successful mitral valve replacement (MVR) in a dialysis-dependent patient. The patient recovered well at postoperation and had the complication of anticoagulation at follow-up. Based on this successful case, we believe that myocardial protection, prevention of infection, nutritional support, and close monitoring of blood coagulation function are important in dialysis-dependent patients undergoing valve replacement.

Drug-Eluting Versus Bare-Metal Stents During PCI in Patients With End-Stage Renal Disease on Dialysis

BACKGROUND

In patients undergoing percutaneous coronary intervention (PCI), drug-eluting stents (DES) reduce repeat revascularizations compared with bare-metal stents (BMS), but their effects on death and myocardial infarction (MI) are mixed. Few studies have focused on patients with end-stage renal disease.

OBJECTIVES

This study compared mortality and cardiovascular morbidity during percutaneous coronary intervention with DES and with BMS in dialysis patients.

METHODS

We identified 36,117 dialysis patients from the USRDS (United States Renal Data System) who had coronary stenting in the United States between April 23, 2003, and December 31, 2010, and examined the association of DES versus BMS with 1-year outcomes: death; death or MI; and death, MI, or repeat revascularization. We also conducted a temporal analysis by dividing the study period into 3 DES eras: Transitional (April 23, 2003, to June 30, 2004); Liberal (July 1, 2004, to December 31, 2006); and Selective (January 1, 2007, to December 31, 2010).

RESULTS

One-year event rates were high, with 38 deaths; 55 death or MI events; and 71 death, MI, or repeat revascularization events per 100 person-years. DES, compared with BMS, were associated with a significant 18% lower risk of death; 16% lower risk of death or MI; and 13% lower risk of death, MI, or repeat revascularization. DES use varied, from 56% in the Transitional era to 85% in the Liberal era and 62% in the Selective era. DES outcomes in the Liberal era were significantly better than in the Transitional Era, but not significantly better than in the Selective Era.

CONCLUSIONS

DES for percutaneous coronary intervention appears to be safe for use in U.S. dialysis patients and is associated with lower rates of death, MI, and repeat revascularization.

The Cerebrovascular-Chronic Kidney Disease Connection: Perspectives and Mechanisms

Chronic kidney disease (CKD) is an independent risk factor for the development of cerebrovascular disease, particularly small vessel disease which can manifest in a variety of phenotypes ranging from lacunes to microbleeds. Small vessel disease likely contributes to cognitive dysfunction in the CKD population. Non-traditional risk factors for vascular injury in uremia include loss of calcification inhibitors, hyperphosphatemia, increased blood pressure variability, elastinolysis, platelet dysfunction, and chronic inflammation. In this review, we discuss the putative pathways by which these mechanisms may promote cerebrovascular disease and thus increase risk of future stroke in CKD patients.

The role of cGMP and its signaling pathways in kidney disease

Cyclic nucleotide signal transduction pathways are an emerging research field in kidney disease. Activated cell surface receptors transduce their signals via intracellular second messengers such as cAMP and cGMP. There is increasing evidence that regulation of the cGMP-cGMP-dependent protein kinase 1-phosphodiesterase (cGMP-cGK1-PDE) signaling pathway may be renoprotective. Selective PDE5 inhibitors have shown potential in treating kidney fibrosis in patients with chronic kidney disease (CKD), via their downstream signaling, and these inhibitors also have known activity as antithrombotic and anticancer agents. This review gives an outline of the cGMP-cGK1-PDE signaling pathways and details the downstream signaling and regulatory functions that are modulated by cGK1 and PDE inhibitors with regard to antifibrotic, antithrombotic, and antitumor activity. Current evidence that supports the renoprotective effects of regulating cGMP-cGK1-PDE signaling is also summarized. Finally, the effects of icariin, a natural plant extract with PDE5 inhibitory function, are discussed. We conclude that regulation of cGMP-cGK1-PDE signaling might provide novel, therapeutic strategies for the worsening global public health problem of CKD.

Prediction of Mortality in Incident Hemodialysis Patients: A Validation and Comparison of CHADS2, CHA2DS2, and CCI Scores

Background

The CHADS2 and CHA2DS2 scores are usually applied for stroke prediction in atrial fibrillation patients, and the Charlson comorbidity index (CCI) is a commonly used scale for assessing morbidity. The role in assessing mortality with score system in hemodialysis is not clear and comparisons are lacking. We aimed at evaluating CHADS2, CHA2DS2, and CCI scores to predict mortality in incident hemodialysis patients.

Methods

Using data from the Nation Health Insurance system of Taiwan (NHIRD) from 1 January 2005 to 31 December 2009, individuals ≧20 y/o who began hemodialysis identified by procedure code and receiving dialysis for > 3 months were included for our study. Renal transplantation patients after dialysis or PD patients were excluded. We calculated the CHADS2, CHA2DS2, and CCI score according to the ICD-9 code and categorized the patients into three groups in each system: 0–1, 2–3, over 4. A total of 3046 incident hemodialysis patients enrolled from NHIRD were examined for an association between the separate scoring systems (CHADS2, CHA2DS2, and CCI score) and mortality.

Results

CHADS2 and CHA2DS2 scores revealed good predictive value for total mortality (CHADS2 AUC = 0.805; CHA2DS2 AUC = 0.790). However, the CCI score did not reveal a similarly satisfying result (AUC = 0.576).

Conclusions

Our results show that CHADS2 and CHA2DS2 scores can be applied for mortality prediction in incident hemodialysis patients.

Percutaneous coronary interventions and antiplatelet therapy in renal transplant recipients

Cardiovascular disease is the leading cause of mortality and morbidity following renal transplantation (RT), accounting for 40-50% of all deaths. After renal transplantation, an adverse cardiovascular event occurs in nearly 40% of patients; given the dialysis vintage and the average wait time, the likelihood of receiving coronary revascularization is very high. There is a significant gap in the literature in terms of the outcomes of prophylactic coronary revascularization in renal transplantation candidates. Current guidelines on myocardial revascularization stipulate that renal transplant patients with significant coronary artery disease (CAD) should not be excluded from the potential benefit of revascularization. Compared with percutaneous coronary intervention (PCI), however, coronary artery bypass grafting is associated with higher early and 30-day mortality. About one-third of renal transplant patients with CAD have to be treated invasively and so PCI is currently the most popular mode of revascularization in these fragile and compromised patients. A newer generation drug-eluting stent (DES) should be preferred over a bare metal stent (BMS) because of its lower risk of restenosis and improved safety concerns (stent thrombosis) compared with first generation DES and BMS. Among DES, despite no significant differences being reported in terms of efficacy, the newer everolimus and zotarolimus eluting stents should be preferred given the possibility of discontinuing, if necessary, dual antiplatelet therapy before 12 months. Since there is a lack of randomized controlled trials, the current guidelines are inadequate to provide a specifically tailored antiplatelet therapeutic approach for renal transplant patients. At present, clopidogrel is the most used agent, confirming its central role in the therapeutic management of renal transplant patients undergoing PCI. While progress in malignancy-related mortality seems a more distant target, a slow but steady reduction in cardiovascular deaths, improving pharmacological and interventional therapy, is nowadays an achievable medium-term target in renal transplant patients.

The Biology of Hemodialysis Vascular Access Failure

Arteriovenous fistulas (AVFs) are essential for patients and clinicians faced with end-stage renal disease (ESRD). While this method of vascular access for hemodialysis is preferred to others due to its reduced rate of infection and complications, they are plagued by intimal hyperplasia. The pathogenesis of intimal hyperplasia and subsequent thrombosis is brought on by uremia, hypoxia, and shear stress. These forces upregulate inflammatory and proliferative cytokines acting on leukocytes, fibroblasts, smooth muscle cells, and platelets. This activation begins initially with the progression of uremia, which induces platelet dysfunction and primes the body for an inflammatory response. The vasculature subsequently undergoes changes in oxygenation and shear stress during AVF creation. This propagates a strong inflammatory response in the vessel leading to cellular proliferation. This combined response is then further subjected to the stressors of cannulation and dialysis, eventually leading to stenosis and thrombosis. This review aims to help interventional radiologists understand the biological changes and pathogenesis of access failure.

Buccal Mucosal Graft Urethroplasty in Patients Awaiting Renal Transplantation

OBJECTIVE

To assess the perioperative morbidity and early outcome of buccal mucosal graft (BMG) urethroplasty in patients with urethral stricture awaiting renal transplantation.

METHODS

Thirteen patients awaiting renal transplantation underwent BMG urethroplasty for long anterior urethral stricture between June 2011 and March 2013. The management issues, complications, and outcome of the BMG urethroplasty in this cohort of patients were studied.

RESULTS

Mean age of the patient was 38.7 ± 12.7 years. History of urethral manipulation was present in 8 patients. Mean stricture length was 6.92 ± 2.90 cm. Mean serum creatinine of the patient was 8.1 ± 3.6 mg%. Three patients required oral exploration for bleeding. Two patients had urinary extravasation, 3 patients had infected hematoma, and 1 patient developed dry gangrene of the glans. One patient had sepsis due to pyonephrosis in the postoperative period and succumbed to it. Mean follow-up of the patients was 34.54 ± 6.46 months. Three patients underwent VIU for recurrence of the stricture in the follow-up. At 3-month follow-up mean Qmax was 23.8 mL/sec, whereas at 6-month and 1-year follow-up, Qmax was 23.6 and 23.4 mL/sec, respectively.

CONCLUSION

This study shows a relatively higher complication rate of urethroplasty in prerenal transplant patients. Although the number of cases is too small to arrive at any definite conclusion, this study does gives an insight into the management issues, complications, and success of urethroplasty in this group of patients.

A Lethal Complication of Endoscopic Therapy: Duodenal Intramural Hematoma

Duodenal intramural hematoma (DIH) usually occurs in childhood and young adults following blunt abdominal trauma. It may also develop in the presence of coagulation disorders and may rarely be an iatrogenic outcome of endoscopic procedures. Management of DIH is usually a conservative approach. A case of intramural duodenal hematoma that developed following endoscopic epinephrine sclerotherapy and/or argon plasma coagulation and that was nonresponsive to conservative therapy in a patient with chronic renal failure who died from sepsis is being discussed in this report. Clinicians should be aware of such possible complications after endoscopic hemostasis in patients with coagulation disorders.

Atrial fibrillation and chronic kidney disease: focus on rivaroxaban

Renal insufficiency increases the risk of stroke and bleeding in atrial fibrillation patients. Although vitamin K antagonists reduce the risk of stroke in patients with moderate renal dysfunction, this observation is less clear in patients with renal impairment. Moreover, the risk of bleeding with vitamin K antagonists increases as renal function worsens. Maintaining international normalized ratio values within therapeutic targets is more difficult in patients with renal dysfunction, and those agents may cause warfarin-related nephropathy and vascular calcification. Rivaroxaban is the only nonvitamin K oral anticoagulant with a dose specifically tested in patients with moderate renal insufficiency. Rivaroxaban is effective for the prevention of stroke in atrial fibrillation patients with moderate renal dysfunction, with a lower risk of intracranial and fatal bleeding.

Risk factors for bleeding evaluated using the Forrest classification in Japanese patients after endoscopic submucosal dissection for early gastric neoplasm

BACKGROUND/AIMS

Bleeding remains a serious complication after endoscopic submucosal dissection (ESD). Second-look endoscopy for hemostasis helps prevent post-ESD bleeding. We investigated the relationships between patient characteristics, tumor characteristics, and the Forrest classification for exposed vessels on artificial ulcers after ESD and evaluated whether hemostasis during second-look endoscopy was useful for preventing post-ESD bleeding.

PATIENTS AND METHODS

We analyzed 250 patients (265 lesions) who underwent ESD for gastric neoplasms. Vessels classified by Forrest classifications during scheduled second-look endoscopy were analyzed for associations with patient characteristics, tumor characteristics, and recurrent bleeding.

RESULTS

Two of 250 patients (0.8%) underwent emergency hemostatic endoscopy before scheduled second-look endoscopy. The remaining 248 patients (99.2%) underwent scheduled second-look endoscopy on the day after ESD. Patients with Forrest classification Ia, Ib, or IIa vessels had a significantly higher risk for recurrent bleeding after scheduled second-look endoscopy compared with patients with IIb or III vessels according to univariate analysis (P<0.05) and multivariate logistic regression analysis (odds ratio: 3.45; 95% confidence interval: 1.04-11.41; P=0.042). Univariate analysis indicated that hemodialysis correlated significantly with the presence of Ia, Ib, or IIa vessels compared with that of IIb or III vessels found during second-look endoscopy (P<0.05). Multivariate analysis indicated a significant relationship between hemodialysis and recurrent bleeding after second-look endoscopy (odds ratio: 10.05; 95% confidence interval: 1.97-51.26; P=0.006).

CONCLUSION

Hemodialysis is a risk factor for post-ESD bleeding. Proper classification of exposed vessels within post-ESD ulcers according to the Forrest classification using second-look endoscopy might help predict or prevent recurrent bleeding.

Antiplatelet Therapy in Hemodialysis Patients Undergoing Percutaneous Coronary Interventions

Context:

Coronary artery disease is highly prevalent among patients with end stage renal disease/hemodialysis (ESRD/HD) and coronary percutaneous interventions (PCI) has been increased by nearly 50% over the past decade. After PCI with stent placement, guidelines recommend dual antiplatelet therapy (DAPT), but no specifically tailored pharmacotherapy approach is outlined for this frail population, mostly excluded from large randomized clinical trials (RCTs).

Evidence Acquisition:

We reviewed current evidences on the use of antiplatelet therapy in patients with ESRD/HD undergoing PCI, focusing on the efficacy and safety of specific agents and their indications for detailed clinical settings.

Results:

Clinical setting in HD patients is the principal determinant of the type, onset, combination and duration of the DAPT. However, irrespective clinical setting, in addition to aspirin, clopidogrel is currently the most used antiplatelet agent even if no information derived from RCTs are available in ESRD. Due to the large experience acquired in routine clinical practice, the awareness of safety is higher for clopidogrel than newer antiplatelet agents. Because of lack of data, the use of prasugrel and ticagrelor is actually not recommended. However, in case of high ischemic and acceptable bleeding risk, they may be selectively used in ESRD/HD.

Conclusions:

This investigation might contribute to delineate the best treatment options for this high risk population.

Hemorrhage as a life-threatening complication after valve replacement in end-stage renal disease patients

OBJECTIVE

Hemodialysis patients have an increased risk of hemorrhage compared to other patients. This study reports the frequencies of hemorrhage and its impact on the survival of hemodialysis patients after valve replacement.

METHODS

A total of 77 consecutive dialysis patients who underwent prosthetic valve surgery from 1991 to 2011 were retrospectively reviewed. Their mean age was 65.8 ± 9.2 years. Forty-three patients (56%) were male. Fifty-nine patients (77%) had aortic valve replacement, and 23 patients (30%) had mitral valve replacement. Bioprosthetic valves were used in 17 patients (22%).

RESULTS

There were seven in-hospital mortalities (9.1%). The overall estimated Kaplan-Meier survival after 3, 5 and 7 years was 66.6 ± 5.6, 51.1 ± 6.3 and 34.4 ± 6.8%, respectively. Seventeen (22%) bleeding events were observed (5.9% per patient-years) in the follow-up period. Six of the nine patients with cerebral hemorrhages and two of the six with gastrointestinal hemorrhages died. There were no differences in the frequencies of hemorrhage between the patients treated with bioprostheses and mechanical valves.

CONCLUSIONS

This study found that 22% of dialysis patients had hemorrhagic events after valve replacement, and approximately half of them died. Particularly, cerebral hemorrhage was fatal and two thirds of the patients died. So we should meditate the methods to reduce hemorrhage. Therefore, new methods to reduce the risk of hemorrhage are urgently needed.

Effect of low-dose proton pump inhibitor on preventing upper gastrointestinal bleeding in chronic kidney disease patients receiving aspirin

BACKGROUND AND AIM

Upper gastrointestinal bleeding (UGIB) leads to significant morbidity and mortality in chronic kidney disease (CKD) patients. This study determined the efficacy of using a low-dose proton pump inhibitor (PPI) to reduce the risk of non-variceal UGIB in CKD patients receiving aspirin.

METHODS

We retrospectively reviewed the medical records of 500 CKD patients who received aspirin between January 2008 and March 2013. Cumulative incidence analysis using the Kaplan-Meier method was performed to analyze the rate of non-variceal UGIB and association with the administration of low-dose PPI.

RESULTS

Of the 500 patients, 191 received low-dose PPI. Over the follow-up period, which lasted 1067 person-years, three patients in the low-dose PPI group (8.9 per 1000 person-years) and 19 patients in the non-PPI group (25.9 per 1000 person-years) developed non-variceal UGIB, respectively (P = 0.113). Low-dose PPI use did not decrease the risk of UGIB in CKD patients, including patients who did not receive dialysis (P = 0.127). However, according to the subgroup analysis of 230 patients who received dialysis, the low-dose PPI group (14.4 per 1000 person-years) demonstrated significantly reduced incidence and risk of non-variceal UGIB in comparison with the non-PPI group (53.8 per 1000 person-years) (P = 0.032).

CONCLUSION

Prophylactic low-dose PPI can reduce the risk of non-variceal UGIB in dialysis patients receiving aspirin.

Renal dysfunction is an independent risk factor for bleeding after gastric ESD

BACKGROUND AND STUDY AIMS

The number of patients with chronic kidney disease (CKD) is increasing worldwide and gastric cancer sometimes occurs with CKD. However, the safety and feasibility of endoscopic submucosal dissection (ESD) for patients with CKD are not clear. The aim of this study is to clarify the feasibility and safety of gastric ESD for patients with CKD.

PATIENTS AND METHODS

This was a multicenter retrospective cohort study. In total, 144 patients with CKD who underwent gastric ESD between May 2003 and October 2012 were enrolled. The patients were divided into three groups: stage 3 (estimated glomerular filtration rate [eGFR]: 30 - 59 mL/min), stage 4 (eGFR: 15 - 29 mL/min), and stage 5 (eGFR: < 15 mL/min) according to the Kidney Disease Improving Global Outcomes Guidelines. The en bloc and curative resection rates and complications were assessed as short-term outcomes. Overall survival was analyzed using Kaplan - Meier methods.

RESULTS

In total, 92 patients were in stage 3 CKD; 23 in stage 4; and 29 in stage 5, including 19 patients in hemodialysis. The en bloc resection rate was 95.8 %. Post-ESD bleeding was observed in four patients with stage 5 CKD (13.8 %), three with stage 4 (13.0 %), and one with stage 3 (1.1 %). All bleeding could be controlled by endoscopic hemostasis, but five patients required blood transfusion. Perforation occurred in two patients (6.9 %) with stage 5 CKD, none (0 %) with stage 4, and two (4.3 %) with stage 3. Multivariate Poisson regression analysis revealed CKD stage 4 was a critical factor related to bleeding, whereas diabetes mellitus and CKD stage 5, which largely consist of patients receiving hemodialysis, were not. The median observation period of patients who achieved curative resection was 25.9 months (range 0.8-112.7 months) and the 3-year overall survival rate was 92.5 %.

CONCLUSIONS

Estimated GFR is a significant independent predictive factor of post-ESD bleeding in patients with CKD.

Long-term risk of upper gastrointestinal hemorrhage after advanced AKI

BACKGROUND AND OBJECTIVES

There are few reports on temporary dialysis-requiring AKI as a risk factor for future upper gastrointestinal bleeding (UGIB). This study sought to explore the long-term association between dialysis-requiring AKI and UGIB.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This nationwide cohort study used data from the Taiwan National Health Insurance Research Database. Patients who recovered from dialysis-requiring AKI and matched controls were selected from hospitalized patients age ≥18 years between 1998 and 2006. The cumulative incidences of long-term de novo UGIB were calculated, and the risk factors of UGIB and mortality were identified using time-varying Cox proportional hazard models adjusted for subsequent CKD and ESRD after AKI.

RESULTS

A total of 4565 AKI-recovery patients and the same number of matched patients without AKI were analyzed. After a median follow-up time of 2.33 years (interquartile range, 0.97-4.81 years), the incidence rates of UGIB were 50 (by stringent criterion) and 69 (by lenient criterion) per 1000 patient-years in the AKI-recovery group and 31 (by stringent criterion) and 48 (by lenient criterion) per 1000 patient-years in the non-AKI group (both P<0.001). When compared with patients in the non-AKI group, the multivariate hazard ratio (HR) for UGIB was 1.30 (95% confidence interval [95% CI], 1.14 to 1.48) for dialysis-requiring AKI, 1.83 (95% CI, 1.53 to 2.20) for time-varying CKD, and 2.31 (95% CI, 1.92 to 2.79) for time-varying ESRD (all P<0.001). Finally, the risk for long-term mortality increased after UGIB (HR, 1.24; 95% CI, 1.12 to 1.38) and dialysis-requiring AKI (HR, 1.66; 95% CI, 1.54 to 1.78).

CONCLUSIONS

Recovery from dialysis-requiring AKI was associated with future UGIB and mortality.

Thienopyridine use after coronary stenting in low income patients enrolled in medicare part D receiving maintenance dialysis

BACKGROUND

Coronary stenting in patients on dialysis has increased by nearly 50% over the past decade, despite heightened risks of associated stent thrombosis and bleeding relative to the general population. We examined clopidogrel, prasugrel or ticlopidine use after percutaneous coronary intervention (PCI) with stenting in patients on dialysis. We conducted 3-, 6-, and 12-month landmark analyses to test the hypothesis that thienopyridine discontinuation prior to those time points would be associated with higher risks of death, myocardial infarction, or repeat revascularization, and a lower risk of major bleeding episodes compared with continued thienopyridine use.

METHODS AND RESULTS

Using the US Renal Data System, we identified 8458 patients on dialysis with Medicare Parts A+B+D undergoing PCI with stenting between July 2007 and December 2010. Ninety-nine percent of all thienopyridine prescriptions were for clopidogrel. At 3 months, 82% of patients who received drug-eluting stents (DES) had evidence of thienopyridine use. These proportions fell to 62% and 40% at 6 and 12 months, respectively. In patients who received a bare-metal stent (BMS), 70%, 34%, and 26% of patients had evidence of thienopyridine use at 3, 6, and 12 months, respectively. In patients who received a DES, there was a suggestion of higher risks of death or myocardial infarction associated with thienopyridine discontinuation in the 3-, 6-, and 12-months landmark analyses, but no higher risk of major bleeding episodes. In patients who received a BMS, there were no differences in death or cardiovascular events, and possibly lower risk of major bleeding with thienopyridine discontinuation in the 3- and 6-month landmark analyses.

CONCLUSIONS

The majority of patients on dialysis who undergo PCI discontinue thienopyridines before 1 year regardless of stent type. While not definitive, these data suggest that longer-term thienopyridine use may be of benefit to patients on dialysis who undergo PCI with DES.

No sustained impact of intermittent extracorporeal liver support on thrombocyte time course in a randomized controlled albumin dialysis trial

Reduction of platelets is a common finding in patients with liver disease and can be aggravated by extracorporeal therapies, e.g. artificial liver support. The impact of extracorporeal albumin dialysis on the time count and time course of platelets in liver failure patients was evaluated in a randomized controlled clinical trial. Mean thrombocyte reduction during a single extracorporeal liver support therapy was -15.1% [95%CI: -17.7; -12.5]. No differences were found between treatments of patients with a more reduced platelet count (<100 GPT/L: -15.6% [-19.5; -11.7%]; n = 43) compared to patients with normal or slightly decreased thrombocytes (-14.6% [-18.3%; -11.0%]; n = 43; P = 0.719). The variation of platelet count within 24 h after onset of extracorporeal therapy treatment was less, albeit significant (-3.5% [-6.3%; -0.7%], P < 0.016). Absolute thrombocyte variability was comparable between both groups (with extracorporeal therapy -5.6 GPT/L [-9.7; -1.4], without extracorporeal therapy -1.3 GPT/L [-7.3; 4.7]; P = 0.243), whereas relative decrease of thrombocytes within a 24-h period of extracorporeal therapy was greater than the changes in patients without extracorporeal therapy (-3.5% [-6.3%; -0.7%] vs. 2.0% [-2.0%; 5.9%]; P = 0.026]. Within a period of two weeks after enrollment, no significant differences of platelet count were observed either between the two groups or in the time course (P(group) = 0.337, P(time) = 0.277). Reduction of platelets during intermittent extracorporeal liver support was less pronounced within a 24-h period as before and after a single treatment and was comparable to variations in the control group without extracorporeal therapy.

Higher mortality due to intracerebral hemorrhage in dialysis patients: a comparison with the general population in Japan

Cerebrovascular diseases, including intracerebral hemorrhage, cerebral infarction, and subarachnoid hemorrhage, remain prevalent causes of morbidity and mortality among dialysis patients. Their mortality rate for cerebrovascular diseases is roughly three times higher than that in the general population. However, whether mortality rates for all subtypes of cerebrovascular diseases are equally higher has not been evaluated. The aim of this study was to determine the mortality rate for each stroke subtype, comparing dialysis patients and the general population in Japan. We used mortality data reported by the Japanese Society for Dialysis Therapy and national Vital Statistics data between 2008 and 2009. We calculated standardized mortality ratios and compared the mortality rates for stroke subtypes including intracerebral hemorrhage, cerebral infarction, and subarachnoid hemorrhage. During the 2-year study period, 51 994 and 933 deaths from intracerebral hemorrhage, 79 124 and 511 deaths from cerebral infarction, and 24 957 and 147 deaths from subarachnoid hemorrhage were recorded per 252 million person-years and per 546 474 dialysis patient-years, respectively. Standardized mortality ratios among dialysis patients relative to the general population were 3.8 (95% confidence interval, 3.6-4.1), 1.3 (1.2-1.4), and 1.3 (1.1-1.6) for intracerebral hemorrhage, cerebral infarction, and subarachnoid hemorrhage, respectively. Intracerebral hemorrhage was the highest cause of mortality in the dialysis population, although cerebral infarction was the highest in the general population. Relative to the general population in Japan, Japanese dialysis patients had higher mortality rates, especially for intracerebral hemorrhage.

Kidney disease and risk of venous thromboembolism: a nationwide population-based case-control study

BACKGROUND

Chronic kidney disease is associated with hemostatic derangements, including both procoagulant activity and platelet dysfunction, which may influence the risk of venous thromboembolism. However, data associating kidney disease with risk of venous thromboembolism are sparse.

OBJECTIVES

We examined whether kidney disease is associated with increased risk of venous thromboembolism.

METHODS

We conducted this nationwide case-control study using data from medical databases. We included 128,096 patients with a hospital diagnosis of VTE in Denmark between 1980 and 2010 (54,473 had pulmonary embolism and 73,623 had deep venous thrombosis only) and 642,426 age- and gender-matched population controls based on risk-set sampling. We identified all previous hospital diagnoses of kidney disease, including nephrotic syndrome, glomerulonephritis without nephrotic syndrome, hypertensive nephropathy, chronic pyelonephritis/interstitial nephritis, polycystic kidney disease, diabetic nephropathy, or other kidney diseases. We used conditional logistic regression models to compute odds ratios (ORs) for venous thromboembolism with adjustment for potential confounders.

RESULTS

Kidney disease was associated with an adjusted OR for venous thromboembolism ranging from 1.41 (95% CI, 1.22-1.63) for hypertensive nephropathy to 2.89 (95% CI, 2.26-3.69) for patients with nephrotic syndrome. The association was strongest within the first 3 months after a diagnosis of chronic kidney disease (adjusted OR for nephrotic syndrome = 23.23; 95% CI, 8.58-62.89), gradually declining thereafter. The risk, however, remained elevated for more than 5 years, especially in patients with nephrotic syndrome and glomerulonephritis.

CONCLUSIONS

Kidney diseases, in particular nephrotic syndrome and glomerulonephritis, were associated with an increased risk of venous thromboembolism.

Platelet volume and plateletcrit in dogs with presumed primary immune-mediated thrombocytopenia

Background

Mean platelet volume (MPV) and plateletcrit (PCT) are indices used in evaluating immune‐mediated thrombocytopenia (IMT) in humans and in dogs with congenital macrothrombocytopenia. These indices may provide clinically valuable information in acquired thrombocytopenia.

Hypothesis/Objectives

Dogs with presumed primary IMT will have increased MPV, and therefore platelet mass (PCT) will increase faster than platelet count (PLT) during recovery.

Animals

Forty‐nine dogs with automated PLT < 30,000/μL because of presumed primary IMT and hematocrit (HCT), PCT, MPV, and platelet distribution width determined from the same complete blood count (CBC), and 46 healthy controls.

Methods

Case‐control retrospective study; PLT, PCT, MPV, and platelet distribution width (PDW) were recorded from CBCs from 49 dogs, with 45 having data collected on the day of presentation. Fifteen were confirmed to have attained a PLT ≥ 75,000/μL on at least 1 CBC within 15 days after admission. The PCT equivalent to a PLT of 75,000/μL (assuming an average MPV) was calculated for comparison with PLT in terms of time to achieve a threshold of platelet mass by the 2 measures.

Results

Mean platelet volume was higher in IMT dogs (17.3 fl) than the reference population (10.5 fl) (P < .0001). The PDW was not significantly different among the groups. The median time for PCT to reach threshold in confirmed responders was faster (3 days) compared with PLT (4 days).

Conclusions and Clinical Importance

Immune‐mediated thrombocytopenia is characterized by increased MPV. Time to achieve a threshold PCT tended to be shorter than PLT, suggesting that PCT may be a useful platelet parameter for monitoring dogs with IMT.

Leptin as an uremic toxin: Deleterious role of leptin in chronic kidney disease

White adipose tissue secretes a large variety of compounds named adipokines amongst which, leptin exhibits pleiotropic metabolic actions. Leptin is an anorexigenic hormone, secreted in proportion of fat mass, with additional effects on the regulation of inflammation, cardiovascular system, immunity, hematopoiesis and bone metabolism. Chronic kidney disease (CKD) is characterized by an increase of plasma leptin concentration that may be explained by a lack of renal clearance. Hyperleptinemia plays a key role in the pathogenesis of complications associated with CKD such as cachexia, protein energy wasting, chronic inflammation, insulin resistance, cardiovascular damages and bone complications. Leptin is also involved in the progression of renal disease through its pro-fibrotic and pro-hypertensive actions. Most of the adverse effects of leptin have been documented both experimentally and clinically. Leptin may therefore be considered as an uremic toxin in CKD. The aim of this review is to summarize the pathophysiological and clinical role of leptin in in vitro studies, experimental models, as well as in patients suffering from CKD.

Anticoagulant and antiplatelet therapy in patients with chronic kidney disease: risks versus benefits review

PURPOSE OF REVIEW

Atrial fibrillation and cardiovascular death are increased in end-stage renal disease (ESRD) patients compared to the general population. The effect of anticoagulant and antiplatelet medications for these indications in ESRD is unclear. However, both classes of medications have been used for the preservation of vascular access. This review explores the risks and benefits of anticoagulant and antiplatelet medications in ESRD.

RECENT FINDINGS

ESRD patients with atrial fibrillation have a two and three-fold greater risk of death and stroke, respectively, than ESRD patients without atrial fibrillation. Warfarin does not appear to decrease this risk, and increases the risk of bleeding and vascular calcification. Warfarin also does not appear to be effective for vascular access preservation. In a few large observational studies, antiplatelet agents did not decrease the risk of cardiovascular death, but confounding by indication is likely. Antiplatelet agents do appear to prolong unassisted arteriovenous graft patency, but the effect is modest.

SUMMARY

The role of anticoagulant and antiplatelet agents for atrial fibrillation and cardiovascular disease in ESRD remains unclear. Well designed randomized controlled trials to determine the role of anticoagulation in ESRD patients with atrial fibrillation, and anticoagulant and antiplatelet medications in the preservation of central venous catheter function are required.

Ameboma: an unusual cause of gastrointestinal bleeding during severe leptospirosis

Background

Severe leptospirosis occurs mainly in a tropical environment and includes icterus, acute renal failure and hemorrhages. These bleedings, which are mainly a consequence of acute homeostatic disturbances, can also reveal simultaneous diseases. Coinfections with other tropical diseases have been previously reported during leptospirosis. To our knowledge, invasive amebiasis, which can induce gastrointestinal bleedings, has never been described in the course of severe leptospirosis.

Case presentation

In this report, we describe a case of a 60 year-old man living in Reunion Island (Indian Ocean, France) admitted to our intensive care unit for severe Leptospira interrogans serovar icterohaemorrhagiae infection with neurological, renal, liver and hematological involvement. Two lower gastrointestinal bleedings occurred 7 and 15 days after admission. The first episode was promoted by hemostatic disturbances while the second bleeding occurred during low-dose heparin therapy. Colonoscopy revealed a pseudo-tumoral inflammatory mass of the recto-sigmoid junction. Histological examination found trophozoites inside mucinous exudate suggestive of Entamoeba histolytica. Amoebic serology was strongly positive whereas careful detection of cysts or trophozoites on saline-wet mount was negative in three consecutive samples of stools. Amoxicillin followed by metronidazole therapy, combined with supportive care, led to an improvement in the clinical and biological patient’s condition and endoscopic appearances.

Conclusion

Clinicians should be aware that gastrointestinal bleeding during severe leptospirosis could not solely be the consequences of hemostatic disturbances. Careful endoscopic evaluation that may reveal curable coinfections should also be considered.

Fatal pulmonary embolism after hemodialysis vascular access declotting

Patient: Male, 59

Final Diagnosis: Pulmonary embolism

Symptoms: Cardiac arrest • chest pain • dyspnea

Medication: —

Clinical Procedure: Angioplasty

Specialty: Nephrology

Hepatic resection for hepatocellular carcinoma patients on hemodialysis for uremia: a nationwide cohort study

BACKGROUND

The association between uremia and survival outcomes of patients undergoing hepatic resection for hepatocellular carcinoma (HCC) has not been well investigated, particularly for perioperative complications. This nationwide cohort study aimed to compare survival outcomes as well as perioperative mortality and complications between uremia-HCC patients and non-uremia-HCC patients who underwent hepatic resection.

METHODS

Using Taiwan's National Health Institute Research Database, 149 uremia-HCC patients who underwent hepatic resection between 1996 and 2008 were enrolled. The control group comprised 596 HCC patients who also received hepatic resection during the same time period. The two groups were matched for age, gender, viral hepatitis status, and underlying liver cirrhosis. Disease-free survival, overall survival, and perioperative complications were compared between the two groups.

RESULTS

For the uremia-HCC cohort, the 1-, 5-, and 10-year overall and disease-free survival rates were 86, 52, and 38 %, as well as 77, 27, and 18 %, respectively. The survival outcomes were comparable between uremia-HCC cohort and the HCC cohort, regardless of extent of hepatic resection. As for perioperative complications, the uremia-HCC cohort had a higher risk of postoperative infections requiring invasive interventions as well as an increased risk of life-threatening heart-associated complications, compared to the HCC cohort.

CONCLUSIONS

Uremia did not influence survival outcomes between the uremia-HCC and the HCC cohorts, irrespective of extent of hepatic resection. This study urges a better perioperative care strategy to avoid potential cardiac and infectious complications in uremia-HCC patients.

Enhanced platelet apoptosis in chronic uremic patients

BACKGROUND

There is a paucity of research on platelet apoptosis and its contribution to platelet dysfunction in uremic patients. The present study sought to analyze platelets apoptosis in uremic patients who underwent different dialysis modalities.

METHODS

Sixteen chronic uremic patients (5 on hemodialysis, 6 on peritoneal dialysis and 5 on non-dialysis) and 16 controls were studied. Platelet-rich plasma was detected for apoptotic events including depolarization of mitochondrial inner membrane potential (ΔΨm), phosphatidylserine (PS) exposure, activation of caspases-3 and Bcl-2 family proteins variations by Flow Cytometry or by Western-Blot. Washed normal platelets were incubated with normal or uremic platelet poor plasma and then were detected apoptotic events. Platelets function was assessed by ristocetin induced aggregative function test.

RESULTS

Compared to controls, uremic platelets demonstrated greater apoptosis for the ΔΨm depolarization (43.48 ± 9.58 vs. 52.76 ± 15.36, p = 0.005) as well as PS exposure (1.36 ± 0.51 vs. 0.99 ± 0.27, p < 0.001). There was no significant difference among different treatment groups (for the ΔΨm depolarization f = 0.16, p = 0.85; for the PS exposure f = 1.06, p = 0.36). Western Blot analyses showed caspase-3 activation and pro-apoptotic Bcl-2 family proteins expression. Platelets exposed to uremic plasma exhibited distinct apoptosis phenomena. Ristocetin induced platelet aggregation was markedly diminished in uremic patients and treated platelets.

CONCLUSIONS

These findings indicate that platelets are incurred apoptosis in uremia patients. Uremic plasma accelerates apoptosis of normal platelets, resulting in a dysfunctional pattern of platelets in uremia. Uremic platelets apoptosis has no relationship with dialysis modality.

Thrombocytopenia in ESRD patients: epidemiology, mechanisms and interventional nephrology perspective

A well-functioning vascular access is essential for provision of life-sustaining dialysis treatment in patients with end-stage renal disease. Arteriovenous accesses are preferred form of vascular access. Although significant advances have been made in the field of dialysis access, arteriovenous access dysfunction remains the single most important cause of morbidity in ESRD patients. While thrombosis and stenosis of AV access are more frequently seen, hemorrhage from AV access can be life threatening with or without risk of permanent access loss. Aside from anticoagulation for comorbidities, qualitative and/or quantitative platelet abnormalities are often the predisposing factors. We describe an ESRD patient who developed new onset but severe thrombocytopenia due to metastatic small cell neuroendocrine carcinoma of lung. Given her persistent thrombocytopenia and presence of prolonged bleeding from the cannulation sites, a right internal jugular tunneled dialysis catheter was placed for continuation of maintenance dialysis. This review discusses the definition of thrombocytopenia, mechanisms of thrombocytopenia in patients with ESRD and with a special focus on implications of thrombocytopenia on dialysis access interventions. The review underscores the need for consensus with regard to cannulating AV access as well as guidelines specific to dialysis access-related endovascular intervention in the setting of thrombocytopenia and other coagulation abnormalities.

Overview of platelet physiology: its hemostatic and nonhemostatic role in disease pathogenesis

Platelets are small anucleate cell fragments that circulate in blood playing crucial role in managing vascular integrity and regulating hemostasis. Platelets are also involved in the fundamental biological process of chronic inflammation associated with disease pathology. Platelet indices like mean platelets volume (MPV), platelets distributed width (PDW), and platelet crit (PCT) are useful as cheap noninvasive biomarkers for assessing the diseased states. Dynamic platelets bear distinct morphology, where α and dense granule are actively involved in secretion of molecules like GPIIb , IIIa, fibrinogen, vWf, catecholamines, serotonin, calcium, ATP, ADP, and so forth, which are involved in aggregation. Differential expressions of surface receptors like CD36, CD41, CD61 and so forth have also been quantitated in several diseases. Platelet clinical research faces challenges due to the vulnerable nature of platelet structure functions and lack of accurate assay techniques. But recent advancement in flow cytometry inputs huge progress in the field of platelets study. Platelets activation and dysfunction have been implicated in diabetes, renal diseases, tumorigenesis, Alzheimer's, and CVD. In conclusion, this paper elucidates that platelets are not that innocent as they keep showing and thus numerous novel platelet biomarkers are upcoming very soon in the field of clinical research which can be important for predicting and diagnosing disease state.

Review article: gastrointestinal angiodysplasia - pathogenesis, diagnosis and management

BACKGROUND

Angiodysplasia (AD) of the gastrointestinal (GI) tract is an important condition that can cause significant morbidity and -rarely - mortality.

AIM

To provide an up-to-date comprehensive summary of the literature evaluating this disease entity with a particular focus on pathogenesis as well as current and emerging diagnostic and therapeutic modalities. Recommendations for treatment will be made on the basis of the current available evidence and consensus opinion of the authors.

METHODS

A systematic literature search was performed. The search strategy used the keywords 'angiodysplasia' or 'arteriovenous malformation' or 'angioectasia' or 'vascular ectasia' or 'vascular lesions' or 'vascular abnormalities' or 'vascular malformations' in the title or abstract.

RESULTS

Most AD lesions (54-81.9%) are detected in the caecum and ascending colon. They may develop secondary to chronic low-grade intermittent obstruction of submucosal veins coupled with increased vascular endothelial growth factor-dependent proliferation. Endotherapy with argon plasma coagulation resolves bleeding in 85% of patients with colonic AD. In patients who fail (or are not suitable for) other interventions, treatment with thalidomide or octreotide can lead to a clinically meaningful response in 71.4% and 77% of patients respectively.

CONCLUSIONS

Angiodysplasia is a rare, but important, cause of both overt and occult GI bleeding especially in the older patients. Advances in endoscopic imaging and therapeutic techniques have led to improved outcomes in these patients. The choice of treatment should be decided on a patient-by-patient basis. Further research is required to better understand the pathogenesis and identify potential therapeutic targets.

End-stage renal disease and outcome in a surgical intensive care unit

Introduction

End-stage renal disease (ESRD) is associated with an increased propensity for critical illness, but whether ESRD is independently associated with a greater risk of death after major surgical procedures is unclear.

Methods

This was a retrospective analysis of prospectively collected data from all adult (>18 years) patients admitted to a 50-bed surgical intensive care unit (ICU) between January 2004 and January 2009. ESRD was defined as the need for chronic peritoneal dialysis or hemodialysis for at least 6 weeks prior to ICU admission. We used multivariable logistic regression analysis and propensity-score matching to adjust for possible confounders.

Results

In total, 12,938 adult patients were admitted during the study period; 199 patients had ESRD at ICU admission, giving a prevalence of 1.5%. Patients with ESRD were more likely to be male (72.9% versus 63.0%, P = 0.004) and had higher severity scores, a higher incidence of diabetes mellitus and cirrhosis, and a lower incidence of cancer at ICU admission than those without ESRD. Patients with ESRD were more likely to have any type of organ failure at ICU admission and during the ICU stay. Patients with ESRD had higher ICU and hospital mortality rates (23.1% and 31.2% versus 5.5% and 10.0%, respectively, P <0.001 pairwise) and longer ICU length of stay (2 (1 to 7) versus 1 (1 to 3) days, P <0.001). In multivariable logistic regression analysis, ESRD was independently associated with a greater risk of in-hospital death (odds ratio = 3.84, 95% confidence interval 2.68 to 5.5, P <0.001). In 199 pairs of patients, hematologic and hepatic failures were more prevalent, ICU and hospital mortality rates were higher (23.1% versus 15.1% and 31.2% versus 19.1%, P <0.05 pairwise), and ICU length of stay was longer (2 (1 to 7) versus 1 (1 to 7) days, P <0.001) in patients with ESRD.

Conclusions

In this large cohort of surgical ICU patients, presence of ESRD at ICU admission was associated with greater morbidity and mortality and independently associated with a greater risk of in-hospital death. Our data can be useful in preoperative risk stratification.

Oral anticoagulant therapy in patients receiving haemodialysis: is it time to abandon it?

Oral anticoagulant (OAC) therapy in haemodialysis patients causes a great deal of controversy. This is because a number of pro- and anticoagulant factors play an important role in end-stage renal failure due to the nature of the disease itself. In these conditions, the pharmacokinetic and pharmacodynamic properties of the OACs used change as well. In the case of the treatment of venous thromboembolism, the only remaining option is OAC treatment according to regimens used for the general population. Prevention of HD vascular access thrombosis with the use of OACs is not very effective and can be dangerous. However, OAC treatment in patients with atrial fibrillation in dialysis population may be associated with an increase in the incidence of stroke and mortality. Doubts should be dispelled by prospective, randomised studies; at the moment, there is no justification for routine use of OACs in the above-mentioned indications. In selected cases of OAC therapy in this group of patients, it is absolutely necessary to control and monitor the applied treatment thoroughly. Indications for the use of OACs in patients with end-stage renal disease, including haemodialysis patients, should be currently limited.