Platelet dysfunction and end-stage renal disease

Outcomes, Trends, and Predictors of Gastrointestinal Bleeding in Patients Undergoing Transcatheter Aortic Valve Implantation (from the National Inpatient Sample)

Major bleeding has been identified as one of the most common complications after transcatheter aortic valve implantation (TAVI) with some suffering gastrointestinal bleeding (GIB). This study aimed at assessing the incidence and predictors of GIB after TAVI in the United States. We performed a retrospective analysis of data from the National Inpatient Sample database from 2011 to 2018. A total of 216,023 hospitalizations for TAVI were included. Of the included patients, 2,188 (1%) patients had GIB, whereas 213,835 (99%) patients did not have GIB. The presence of arteriovenous malformation was associated with the highest odds of having a gastrointestinal bleed (odds ratio (OR) 24.8, 95% confidence interval (CI) 17.13 to 35.92). Peptic ulcer disease was associated with an eightfold increased risk of bleeding (OR 8.74, 95% CI, 6.69 to 11.43) followed closely by colorectal cancer (OR 7.89, 95% CI, 5.33 to 11.70). Other comorbidities that were associated with higher propensity-matched rates of GIB were chronic kidney disease (OR 1.27,95% CI, 1.14 to 1.41), congestive heart failure (OR 1.18, 95% CI,1.06 to 1.32), liver disease (OR1.83, 95% CI,1.53 to 2.19), end-stage renal disease (OR 2.08,95% CI, 1.75 to 2.47), atrial fibrillation (OR1.63,95% CI,  1.49 to 1.78), and lung cancer (OR 2.80, 95% CI,1.77 to 4.41). Patients with GIB had higher propensity-matched rates of mortality than those without GIB, (12.1% vs 3.2%, p <0.01). Patients with GIB had a higher median cost of stay ($68,779 vs $46,995, p <0.01) and a longer length of hospital stay (11 vs 3 days, p <0.01). In conclusion, health care use and mortality are higher in hospitalizations of TAVI with a GIB. Baseline comorbidities like peptic ulcer disease, chronic kidney disease, liver disease, atrial fibrillation and, colorectal cancer are significant predictors of this adverse event.

A Case of Bilateral Hemorrhagic Pleural Effusion Due to Dual Antiplatelet Therapy in a Dialysis Patient

Etiologies of hemorrhagic pleural effusions (hemithoraces) are multifactorial. They can be traumatic, non-traumatic, or idiopathic in nature. In this report, we present a rare case of a 64-year-old male with end-stage renal disease (ESRD) on chronic hemodialysis and dual antiplatelet therapy (DAPT), due to a recent history of coronary arterial stent placement, who presented with progressive shortness of breath for one month. The CT of the chest revealed bilateral large pleural effusions (left > right) with a complete collapse of the left lung and partial collapse of the right lung. Ultrasound-guided left-sided thoracentesis revealed hemorrhagic pleural effusions. After the discontinuation of DAPT, drainage from the right-sided pleural effusion via a pigtail catheter showed continued drainage of pleural fluid without hemorrhage. The effusion on the left side was also noted to have resolved on the repeat chest X-ray. Prompt recognition of this rare cause of any hemorrhagic pleural effusion is essential for patients on dialysis to avoid complications. This report focuses on the possible etiology and potential complications of a hemorrhagic pleural effusion, followed by a brief discussion on the rare but significant association involving the incidence of a hemorrhagic pleural effusion in a dialysis patient receiving DAPT.

Lower rates of endoscopy and higher mortality in end-stage renal disease patients with gastrointestinal bleeding: A propensity matched national study

BACKGROUND AND AIM

Patients with end-stage renal disease (ESRD) on hemodialysis are considered to be at higher risk of gastrointestinal bleeding (GIB) as compared with those without renal disease (NRD). We conducted a population-based study using the National Inpatient Sample (NIS) database to study the outcomes of GIB in ESRD.

METHODS

Patients admitted with GIB (upper and lower) from 2005 to 2013 were extracted from the NIS database using ICD-9 codes. Patients were divided into NRD and ESRD groups, and a 1:1 propensity matched analysis was performed. Various outcomes were compared in both groups, and subgroup analysis based on the timing of endoscopy was also performed.

RESULTS

A total of 218 032 patients were included in the study. There was an increase in inpatient admissions among ESRD patients with GIB with significant reduction in mortality (P < 0.001). In-hospital mortality, length of stay, and total costs were significantly higher in ESRD patients as compared with NRD. ESRD patients were less likely to undergo endoscopic evaluation compared with NRD (P < 0.001). Late endoscopy (> 48 h) was associated with increased need for transfusion and health-care utilization but without a significant difference in mortality as compared with early endoscopy. On multivariate analysis, endoscopy was associated with significantly lower rate of mortality in ESRD patients with GIB (odds ratio 0.28, P < 0.0001).

CONCLUSION

End-stage renal disease patients with GIB had a significantly higher rate of mortality and a higher health-care utilization with a lower rate of endoscopic evaluation. Endoscopy was associated with a lower mortality rate on multivariate analysis.

Single Versus Multiple Arterial Revascularization in Patients With Reduced Renal Function: Long-term Outcome Comparisons in 23,406 CABG Patients From Ontario, Canada

OBJECTIVE

To compare the long-term outcomes of MAR versus SAR in patients with renal insufficiency.

SUMMARY OF BACKGROUND DATA

Previous studies have been insufficiently powered to address whether MAR confers long-term benefit over SAR in patients with renal dysfunction who require CABG.

METHODS

We conducted retrospective cohort study in Ontario, Canada of patients who underwent isolated CABG (n = 23,406). The primary outcome was MACE, defined as the composite of stroke, myocardial infarction, and repeat revascularization. We compared patients by matching them on the propensity to have received SAR versus MAR, within groups with preoperative glomerular filtration rate (GFR) ≥60 mL/min/1.73 m2; GFR between 30 and 60; and GFR <30.

RESULTS

In patients with GFR ≥60, the use of MAR versus SAR was associated with a lower rate of MACE [hazard ratio (HR) 0.87 (0.80-0.94)], and a lower rate of long-term mortality [HR 0.87 (0.79-0.97)]. In those with GFR between 30 and 60, MAR was not associated with a difference in MACE [HR 1.04 (0.87-1.26)], and a lower rate of long-term mortality [HR 0.75 (0.65-0.87)] was observed. In those with GFR <30, MAR was not associated with a difference in outcomes.

CONCLUSIONS

MAR versus SAR does not correlate with a difference in MACE amongst patients with GFR between 30 and 60 and better survival raises the possibility of indication bias. Furthermore, MAR did not confer a benefit in those with severely reduced renal function. These data suggest that the potential long-term benefits of using MAR in CABG patients with renal insufficiency may be offset by competing health risks.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Predictors of percutaneous access-related complications in aortic endovascular procedures - 'real-world' insights and a comparison to open access

BACKGROUND

Percutaneous endovascular aneurysm repair (PEVAR) is becoming increasingly popular due to fewer access-related complications, shorter procedural times and length of stay (LOS). Our aim was to explore factors associated with access-related complications and their impact on procedural time and LOS.

METHODS

We retrospectively analysed consecutive aorto-iliac endovascular procedures in a tertiary hub comprising 2 institutions and 18 consultant vascular surgeons and interventional radiologists between 2016 - 2017. Access-related complications were defined as: bleeding requiring cutdown or return to theatre, acute limb ischaemia or common femoral artery (CFA) pseudoaneurysm requiring intervention and wound infection or dehiscence needing hospitalization.

RESULTS

Of 511 patients, 354 (69%) had a percutaneous approach via 589 CFA access sites. In this percutaneous group, access-related complications occurred in 11% of sites (65/589); Their rate varied with procedure type ranging between 3.6% to 17.6%. The most common complication was bleeding due to closure device failure in 8.5% (50/589) of access sites. When uncomplicated, percutaneous interventions were faster compared to open surgical access (p<0.0001). Operation time and median LOS (3 vs. 2 days) were longer for elective standard EVAR patients experiencing access-related complications (p=0.033). In the percutaneous group, multivariate regression analysis demonstrated significant associations between accessrelated complications and eGFR (odds ratio (OR) 0.984 [0.972-0.997], p=0.014), CFA depth (OR 1.026 [1.008-1.045], p=0.005), device used (Prostar vs. Proglide (OR 2.177 [1.236-3.832], p=0.007) and procedural type (complex vs. standard EVAR) (OR 2.017 [1.122-3.627], p=0.019). We developed a risk score which had reasonably good predictive power (C-statistic 0.716 [0.646-0.787],p<0.0001) for avoiding access complications.

CONCLUSIONS

Physiological (low eGFR level), anatomical (increased CFA depth) and technical factors (choice of device and complex procedures) were identified as predictors of access-related complications in this large retrospective series. These are important for safe selection of patients that would benefit from percutaneous access.

Safety Comparison of Monotherapy Aspirin to Dual Antiplatelet Therapy Following Coronary Artery Bypass Surgery

BACKGROUND

Dual antiplatelet therapy (DAPT) is recommended over single antiplatelet therapy (SAPT) in patients following coronary artery bypass grafting (CABG). The compilation of evidence has focused on the efficacy of DAPT to limit risk of graft occlusion, however the safety, especially in the on-pump CABG population, is less well described. The aim of this study was to assess the safety of DAPT versus SAPT after on-pump CABG.

METHODS

This was a single-center, retrospective cohort analysis of adult patients following isolated on-pump CABG between January 2012 and December 2019 not on oral anticoagulation at discharge. The primary endpoint was occurrence of a composite bleeding event identified by pre-specified ICD codes. Secondary endpoints consisted of 30-day and 1-year mortalities along with individual bleeding components.

RESULTS

Of the 2341 patients included 1250 patients were in the SAPT arm and 1091 patients in the DAPT arm. The study populations differed by age, prior MI, PAD, and CHF status/stage. Bleeding events occurred in a total of 70 patients (3.0%), with 36 patients (2.9%) in the SAPT arm and 34 patients (3.1%) in the DAPT arm (P = .74). 30-day (SAPT 0.7% vs DAPT 0.4%) and 1-year (SAPT 3.3% vs DAPT 2.3%) mortality were not significantly different between groups. The most frequent bleed event was in the gastrointestinal tract.

CONCLUSION

In this study, DAPT was not associated with an increase in composite bleeding compared to SAPT. This study could reduce the barrier to prescribing of DAPT given previous efficacy data.

Comparison of cold snare polypectomy and endoscopic mucosal resection for 3-10-mm colorectal polyps in end-stage renal disease patients

BACKGROUND

: Patients with end-stage renal disease (ESRD) have a higher incidence of clinically relevant complications, such as bleeding and perforation after polyp resection, compared to patients without underlying diseases. Cold snare polypectomy (CSP) is increasingly used for the removal of small polyps and diminutive polyps due to its shorter procedure time and low risk of bleeding and perforation. However, there have been few studies on the effectiveness and safety of CSP in patients with ESRD. The aim of this study was to compare the efficacy and safety of CSP and endoscopic mucosal resection (EMR) in ESRD patients.

METHODS

: This study was a retrospective study. We performed propensity score-matched analysis in patients with ESRD who underwent endoscopic resection for 3-10-mm-sized colorectal polyps at Seoul St. Mary's Hospital, from January 2014 to December 2019.

RESULTS

: After 1:1 ratio matching, 406 polyps were included: 203 polyps were resected with CSP and 203 polyps with EMR. There was no difference between the CSP group and EMR group in incomplete resection rate (4.43% vs. 1.97%, P = 0.16). There were no differences between the CSP and EMR group for immediate bleeding (5.42% vs. 7.88%, P = 0.32) and delayed bleeding (0% vs. 0.49%, P = 1.00). No perforation occurred in either group.

CONCLUSIONS

: There were no differences between the CSP and EMR group in terms of efficacy and safety. CSP can be one of the standard methods for the removal of 3-10-mm-sized colorectal polyps in patients with ESRD.

Laparoscopic Ventral Hernia Repair Postoperative Complications in End Stage Renal Disease Patients

Background:

The prevalence of patients with end stage renal disease (ESRD) requiring general surgical procedures is increasing. Our aim was to explore the effect of ESRD on patients undergoing elective laparoscopic ventral hernia repair.

Methods:

The American College of Surgeons National Surgical Quality Improvement Program (2010–2015) database was used to identify patients who underwent elective laparoscopic ventral hernia repair. Multivariable analysis was performed adjusting for risk variables including age, gender, race, comorbidity status, body mass index ≥ 35, and presence of ESRD.

Results:

A total of 8,789 patients undergoing elective laparoscopic ventral hernia repair were identified. Sixty-four patients (0.73%) had ESRD. ESRD was identified as an independent risk factor for postoperative pneumonia (odds ration [OR] 6.91, p = 0.00363), sepsis (OR 18.58, p = 0.000286), and length of stay (IRR 1.63, 95% confidence interval 1.19 – 2.27, p = 0.0036).

Conclusions:

ESRD patients undergoing elective laparoscopic ventral hernia repair had an increased risk of postoperative pneumonia, sepsis, and length of stay. Clinicians should be cognizant of these risks when performing elective operations on ESRD patients.

A Case of Limb-Threatening Hematoma in a Patient Taking Citalopram and Apixaban Concurrently

Apixaban, a direct oral anticoagulant, has been demonstrated to increase the risk of bleeding in individuals with atrial fibrillation when used concurrently with citalopram [selective serotonin reuptake inhibitor (SSRI)]. This was proposed as a result of their synergistic anticoagulant effects. We discuss a rare case in which a limb-threatening hematoma was noticed in an 85-year-old female patient who was just begun on citalopram and was on apixaban. There are few published case studies demonstrating a link between these two kinds of drugs, and our case study aims to inform our audience about the possible negative effects of concurrent usage of these two medications.

Chronic Kidney Disease of Unknown Etiology (CKDu) in Sri Lanka: Hematological Changes and Pro-Inflammation Suggest Likely Predictors of Advance Disease, as Renal Outcomes Show Prevalent Normoalbuminuria

CKDu needs to be characterized in fundamental areas to improve etiological understanding and disease management. In a cross-sectional study, blood cell profile and plasma inflammatory cytokines were followed by automated analysis and sandwich ELISA, respectively. Disease development stages and proteinuria were ascertained by eGFR and UACR. Comparison among control and stages (ANOVA/Dunnett’s MRT) revealed time-specific changes (p < 0.05), including decreased erythrocytes (G5) and hematocrit (G5), and increased MCHC (G3b, G4), MCV (G5), and MCH (G5). CKDu decreased (p < 0.05) lymphocytes (G3b, G4, G5), monocytes (G3b), MPV (G3b, G4, G5), and plateletcrit (G3b, G4), and increased basophils (G3a, G3b, G4), N/L (G4) and PLR (G4–G5). MCHC and aforesaid leukocyte variables were in correlation (rho > ±0.03, p < 0.05, Pearson’s test) with disease development. MCP-1 and IL-6 spiked (p > 0.05) at G3b. Multivariate analyses confirmed that MCP-1, lymphocytes, and BMI were related to renal dysfunction, pointing to inflammation, compromised immunity, and muscle wasting as CKDu effects. Nonproteinuric CKDu was prevalent (23.2–35.6% of total CKDu) with (p < 0.05) elevated basophils (G3a), N/L (G4), and depleted lymphocytes (G4). In both forms, G1–G2 were unaffected, and the earliest change was G3a basophils. Results suggest that MCP-1, lymphocyte count, N/L, and PLR may verify the stage and predict impending ESRD in advance proteinuric CKDu.

Pediatric hemodialysis access

Pediatric hemodialysis access is a demanding field. Procedures are infrequent, technically challenging, and associated with high complication and failure rates. Each procedure affects subsequent access and transplants sites. The choice is made easier and outcomes improved when access decisions are made by a multidisciplinary, pediatric, hemodialysis access team. This manuscript reviews the current literature and offers technical suggestions to improve outcomes.

Extractions in kidney transplant recipients: A prospective observational pilot study

BACKGROUND

The authors undertook a prospective study to determine whether kidney transplant recipients had an increased risk of developing complications, such as local acute infection, alveolitis, increased bleeding, pain, and delayed healing, after tooth extraction.

METHODS

The authors selected patients who underwent kidney transplants more than 6 months ago (study group) and patients who had not (control group) older than 18 years who needed to undergo extraction of erupted teeth. The same oral surgeon performed all tooth extractions while the patients were under local anesthesia. Another blind researcher examined the patients 3, 7, and 21 days after tooth extraction. The first end point was occurrence of complications (local acute infection, alveolitis, increased bleeding), and the second end point was socket reepithelialization on day 21.

RESULTS

Forty-five tooth extractions were performed on 38 study group participants and 61 on 57 control group participants. There was no statistical difference between the groups regarding the incidence of any complication or delayed socket epithelialization.

CONCLUSIONS

The results of this pilot study suggest that there is no difference in postoperative healing after tooth extractions between stable kidney transplant patients and control patients.

PRACTICAL IMPLICATIONS

This is the first prospective study assessing the frequency of postoperative complications after tooth extraction in kidney transplant recipients. This clinical trial was registered at ClinicalTrials.gov. The registration number is NCT02547753.

ACEi/ARBs associate with lower incidence of gastrointestinal bleeding in peritoneal dialysis patients

BACKGROUND

Gastrointestinal bleeding (GIB) is widespread in patients with impaired renal function. Whether angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEi/ARBs) potentially take a crucial role in avoiding GIB incidence among peritoneal dialysis (PD) patients is unknown.

METHODS

Overall, 734 PD patients were enrolled after using propensity score matching. Kaplan-Meier analysis and COX regression were used to explore correlation between ACEi/ARBs and GIB. Competitive risk model was aimed to identify whether other events were confounding factors. Forest plot was applied to assess the influence of ACEI/ARBs on GIB incidence in different groups.

RESULTS

During 8-year follow-up, 89 (12.13%) cases of GIB were recorded. Kaplan-Meier analysis revealed that the incidence of GIB among patients taking ACEi/ARBs was lower than those subjects who had not (log rank = 6.442, P = 0.011). After adjusted different confounding factors, administration of ACEi/ARBs was associated with lowered GIB incidence (adjusted HR = 0.49, 95% CI 0.32-0.77, P = 0.002). In competitive risk model, considering of other events, the incidence of GIB in two groups was still statistically significant (P = 0.010). Subgroup analysis showed ACEi/ARBs taking impeded GIB in the ≥ 60 age group (HR = 0.52, 95% CI 0.28-0.98, P = 0.040).

CONCLUSION

PD patients who were submitted to ACEi/ARBs inclined to have a lower risk for GIB. In this regard, ACEi/ARBs offered a promising choice to GIB.

Changes in hemostatic factors after kidney transplantation: A retrospective cohort study

Chronic kidney disease affects hemostasis in complex ways, producing both thrombotic and hemorrhagic diatheses. These changes may impact patient morbidity and mortality pre-transplantation, as well as allograft survival after kidney transplantation (KT). This study was conducted to analyze changes in hemostatic factors in the early post-KT period.We retrospectively analyzed 676 recipients of kidney allografts from December 2009 to December 2014. Patients receiving plasmapheresis pre- or post-KT, experiencing early allograft failure, or receiving anticoagulants or antiplatelet agents pre- or post-KT were excluded.Of the 367 included patients, acute (≤1 month) rejection occurred in 4.1% and delayed graft function occurred in 3.3%. Postoperative bleeding complications occurred in 7.9% of patients and thrombotic complications in 3.3%. Pre-transplantation, recipients had below normal hemoglobin, above normal d-dimer and homocysteine levels, and elevated rates of antiphospholipid antibodies. Hemoglobin increased to almost normal by postoperative day (POD) 28 (P  < .001). d-dimer increased on POD7, 14, and 28, although the values were not significantly different from pre-KT. The pattern of d-dimer changes suggested that they were a nonspecific consequence of major surgery. Homocysteine decreased to normal by POD7 (P  < .001). The percentage of patients with ≥1 prothrombotic factor was 82.0% pre-KT and only 14.2% on POD28 (P  < .001).The most of patients exhibited prothrombotic tendencies, including increased d-dimer and homocysteine, and increased prevalence of antiphospholipid antibodies before transplantation. They also had pre-transplantation anemia, suggesting a concomitant bleeding diathesis. However, most of these abnormal hemostatic factors improved or resolved after KT.

Coagulation Abnormalities in Renal Pathology of Chronic Kidney Disease: The Interplay between Blood Cells and Soluble Factors

Coagulation abnormalities in renal pathology are associated with a high thrombotic and hemorrhagic risk. This study aims to investigate the hemostatic abnormalities that are related to the interaction between soluble coagulation factors and blood cells, and the effects of hemodialysis (HD) on it, in end stage renal disease (ESRD) patients. Thirty-two ESRD patients under HD treatment and fifteen healthy controls were included in the study. Whole blood samples from the healthy and ESRD subjects were collected before and after the HD session. Evaluation of coagulation included primary and secondary hemostasis screening tests, proteins of coagulation, fibrinolytic and inhibitory system, and ADAMTS-13 activity. Phosphatidylserine (PS) exposure and intracellular reactive oxygen species (iROS) levels were also examined in red blood cells and platelets, in addition to the platelet activation marker CD62P. Platelet function analysis showed pathological values in ESRD patients despite the increased levels of activation markers (PS, CD62P, iROS). Activities of most coagulation, fibrinolytic, and inhibitory system proteins were within the normal range, but HD triggered an increase in half of them. Additionally, the increased baseline levels of ADAMTS-13 inhibitor were further augmented by the dialysis session. Finally, pathological levels of PS and iROS were measured in red blood cells in close correlation with variations in several coagulation factors and platelet characteristics. This study provides evidence for a complex coagulation phenotype in ESRD. Signs of increased bleeding risk coexisted with prothrombotic features of soluble factors and blood cells in a general hyperfibrinolytic state. Hemodialysis seems to augment the prothrombotic potential, while the persisted platelet dysfunction might counteract the increased predisposition to thrombotic events post-dialysis. The interaction of red blood cells with platelets, the thrombus, the endothelium, the soluble components of the coagulation pathways, and the contribution of extracellular vesicles on hemostasis as well as the identification of the unknown origin ADAMTS-13 inhibitor deserve further investigation in uremia.

Effects of Bivalirudin and Unfractionated Heparin on Liver and Renal Function in Chinese Patients with Coronary Artery Disease Undergoing Coronary Angiography with/without Percutaneous Coronary Intervention

BACKGROUND AND AIMS

Unfractionated heparin (UFH) and bivalirudin are widely used as anticoagulants in cardiovascular medicine, including for thrombosis prevention during coronary angiography (CAG) and percutaneous coronary intervention (PCI). Little is known of the effects of UFH and bivalirudin on liver and kidney function in patients subjected to these procedures. This study compared the effects of bivalirudin and UFH on liver/renal function in patients with coronary artery disease who underwent CAG, with or without PCI.

METHODS

The study comprised 134 consecutive patients (40-89 years-old), who underwent CAG (or CAG and PCI); among them, 66 and 68 patients were subject to, respectively, bivalirudin or UFH. The following indicators of liver/renal function were measured before and after the procedures: plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen, estimated glomerular filtration rate (eGFR), creatinine clearance, and serum creatinine. Patients were further stratified by severity of chronic kidney disease (CKD), based on original eGFR.

RESULTS

Relative to baseline, in the bivalirudin group, ALT and AST were higher after CAG (p=0.005, 0.025), while blood urea nitrogen and serum creatinine were lower (p=0.049, <0.001). In the UFH group, ALT, AST, eGFR, and creatinine clearance were lower after CAG (p≤0.001, all). Patients given bivalirudin with moderate or severe CKD, but not those with mild CKD, gained significant improvement in kidney function.

CONCLUSIONS

Relative to UFH, bivalirudin may better safeguard the renal function of patients with coronary artery disease who undergo CAG, especially patients with moderate-to-severe renal insufficiency. UFH may cause less liver damage than bivalirudin.

Evaluation of platelet function in cats with and without kidney disease: a pilot study

OBJECTIVES

The aims of this study were to determine if stable chronic kidney disease (CKD) cats and uremic crisis cats have altered platelet function, and to determine the prevalence of positive fecal occult blood in CKD cats.

METHODS

Platelet function in normal cats, clinically stable International Renal Interest Society (IRIS) stage 2-4 CKD cats and CKD cats experiencing a uremic crisis were evaluated using impedance aggregometry. Area under the curve (AUC) at 6 mins was calculated for saline, adenosine diphosphate (AUCADP) and arachidonic acid (AUCASPI). The AUC in addition to hematocrit, platelet count and mean platelet volume (MPV) were compared between groups using the Kruskal-Wallis test followed by Dunn's post-hoc analysis. Guaiac fecal occult blood tests were performed on fecal samples and results were compared between groups using a χ2 for trend test.

RESULTS

AUCADP (P = 0.04) and AUCASPI (P = 0.05) were significantly higher in uremic crisis cats compared with normal cats at 6 mins. Hematocrit was significantly higher in normal cats when compared with IRIS stage 3 and 4 (P = 0.002) and uremic crisis (P = 0.0008) cats, with no difference among groups for platelet count or MPV. The proportion of cats with positive fecal occult blood samples was significantly different between groups (P = 0.0017); 50% uremic crisis cats, 33% IRIS stage 3 and 4 cats, and 10% IRIS stage 2 cats were positive, while no normal cats were positive. The proportion of cats with platelet clumping was significantly different between groups (P = 0.03).

CONCLUSIONS AND RELEVANCE

Platelet hyper-reactivity may be occurring in CKD cats experiencing a uremic crisis. The etiology of positive fecal occult blood samples in CKD cats is unclear and did not appear to be related to decreased platelet function as measured in this study and requires further investigation.

Investigation of platelet function in patients with chronic kidney disease stages IV-V

INTRODUCTION

Patients with renal failure are at increased risk of both bleeding and thrombosis. Further descriptions of laboratory investigations in these patients are required.

METHODS

Investigation of 24 patients with chronic kidney disease (CKD) stages IV-V with light transmission aggregometry, platelet secretion assays and platelet nucleotide analysis. Patients were in a nonbleeding state and not on antiplatelet medication. Results were compared with our local reference range used within the clinical haematology service.

RESULTS

Of the 24 patients, two had decreased responses to arachidonic acid, adenosine diphosphate, collagen, thrombin receptor activator peptide-6 and one had decreased responses to high dose ristocetin, and one had increased response to low dose ristocetin. 11 and 13 out of 24 had abnormal platelet secretion release to collagen and thrombin, respectively. Platelet nucleotide analysis in patients was normal with the exception of a reduction in ADP content in one patient and ATP/ADP ratio in one patient.

CONCLUSIONS

In our collection of patients with CKD investigated for platelet function in the nonbleeding state, they generally had normal light transmission aggregometry and nucleotide analysis but around 50% had decreased platelet secretion assays. These results could be important in determining the significance of platelet function tests in patients with bleeding symptoms and renal failure. Further characterization of platelet function tests in future will help characterize haemostasis in renal failure further.

Diagnostic complexity of rifampicin-induced coagulopathy in a patient with spontaneous muscle bleeding: A case report

INTRODUCTION

Rifampicin is currently used to treat various bacterial infections, with the most significant application in the treatment of tuberculosis. Dose-independent side effects of the drug can lead to the development of various coagulation disorders, among which disseminated intravascular coagulation is the most dangerous. The mechanism of coagulopathy itself is multifactorial, but it is thought to be mediated by an immune response (formation of antigen-antibody complexes) and consequent damage to platelets and the vascular endothelium.

PATIENT CONCERNS

A 66-year-old woman, with numerous comorbidities including chronic renal failure, condition after implantation of a permanent pacemaker, and a positive blood culture for Staphylococcus aureus, presented with spontaneous bleeding in the muscle wall, and in the clinical picture of hemorrhagic shock.

DIAGNOSIS

Knowing the multifactorial mechanism of rifampicin-induced coagulopathy, possible factors were considered, such as infections, comorbidities, drug use and drug-drug interactions, pathological laboratory parameters, and coagulograms. Clinical presentation of abdominal pain and intra-abdominal mass, with laboratory verification of prolonged activated partial thromboplastin time and computed tomography-proven hematoma suspected of acute bleeding, redirects clinical suspicion of drug-induced coagulopathy.

INTERVENTIONS

By discontinuing rifapicin and administering vitamin K and fresh frozen plasma, normalization of laboratory coagulation parameters was achieved. Bleeding from the muscle wall required correction of acute anemia with red cell concentrates, surgical intervention, and additional antibiotic therapy for secondary infection of the operative wound.

OUTCOMES

At the end of 6 weeks of antibiotic (antistaphylococcal) therapy (due to the basic suspicion of possible infectious endocarditis), the normalization of inflammatory parameters occurred with a sterile control blood culture and a normal coagulogram.

CONCLUSION

Clinicians should be aware of the possible side effects of the administered drugs, especially taking into account the overall clinical picture of a patient, including comorbidities and possible drug interactions.

Epidemiology, thrombolytic management, and outcomes of acute stroke among patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

The relative frequency of ischemic versus hemorrhagic stroke among patients with chronic kidney disease (CKD) has not been clearly described. Moreover, no recent meta-analysis has investigated the outcomes of patients with CKD treated with thrombolysis for acute ischemic stroke. We conducted a systematic review and meta-analysis to estimate the proportion of stroke subtypes and the outcomes of thrombolysis in CKD.

METHODS

A PubMed, EMBASE and Cochrane literature research was conducted. The primary outcome was the proportion and incidence of ischemic versus hemorrhagic strokes among patients with CKD. In addition, we assessed the impact of CKD on disability, mortality, and bleeding among patients with acute ischemic stroke treated with thrombolysis. The pooled proportion and the risk ratio (RR) were estimated using a random-effects model.

RESULTS

Thirty-nine observational studies were included: 22 on the epidemiology of stroke types and 17 on the outcomes of thrombolysis in this population. In the main analysis (> 99,281 patients), ischemic stroke was more frequent than hemorrhagic among patients with CKD (78.3%, 95% confidence interval 73.3%-82.5%). However, among patients with kidney failure, the proportion of ischemic stroke decreased and was closer to that of hemorrhagic stroke: 59.8% (95% confidence interval 49.4%-69.4%). CKD was associated with worse clinical outcomes in patients with acute ischemic stroke compared with patients with preserved kidney function.

CONCLUSIONS

The relative frequency of hemorrhagic stroke seems to increase as kidney function declines. Among patients with acute ischemic stroke treated with thrombolysis, presence of CKD is associated with higher disability, mortality, and bleeding, compared with patients with preserved kidney function.

Chronic Kidney Disease and Cerebrovascular Disease: Consensus and Guidance From a KDIGO Controversies Conference

The global health burden of chronic kidney disease is rapidly rising, and chronic kidney disease is an important risk factor for cerebrovascular disease. Proposed underlying mechanisms for this relationship include shared traditional risk factors such as hypertension and diabetes, uremia-related nontraditional risk factors, such as oxidative stress and abnormal calcium-phosphorus metabolism, and dialysis-specific factors such as cerebral hypoperfusion and changes in cardiac structure. Chronic kidney disease frequently complicates routine stroke risk prediction, diagnosis, management, and prevention. It is also associated with worse stroke severity, outcomes and a high burden of silent cerebrovascular disease, and vascular cognitive impairment. Here, we present a summary of the epidemiology, pathophysiology, diagnosis, and treatment of cerebrovascular disease in chronic kidney disease from the Kidney Disease: Improving Global Outcomes Controversies Conference on central and peripheral arterial disease with a focus on knowledge gaps, areas of controversy, and priorities for research.

Investigating the Multi-Faceted Nature of Radiation-Induced Coagulopathies in a Göttingen Minipig Model of Hematopoietic Acute Radiation Syndrome

Coagulopathies are well documented after acute radiation exposure at hematopoietic doses, and radiation-induced bleeding is notably one of the two main causes of mortality in the hematopoietic acute radiation syndrome. Despite this, understanding of the mechanisms by which radiation alters hemostasis and induces bleeding is still lacking. Here, male Göttingen minipigs received hematopoietic doses of 60Co gamma irradiation (total body) and coagulopathies were characterized by assessing bleeding, blood cytopenia, fibrin deposition, changes in hemostatic properties, coagulant/anticoagulant enzyme levels, and markers of inflammation, endothelial dysfunction, and barrier integrity to understand if a relationship exists between bleeding, hemostatic defects, bone marrow aplasia, inflammation, endothelial dysfunction and loss of barrier integrity. Acute radiation exposure induced coagulopathies in the Göttingen minipig model of hematopoietic acute radiation syndrome; instances of bleeding were not dependent upon thrombocytopenia. Neutropenia, alterations in hemostatic parameters and damage to the glycocalyx occurred in all animals irrespective of occurrence of bleeding. Radiation-induced bleeding was concurrent with simultaneous thrombocytopenia, anemia, neutropenia, inflammation, increased heart rate, decreased nitric oxide bioavailability and endothelial dysfunction; bleeding was not observed with the sole occurrence of a single aforementioned parameter in the absence of the others. Alteration of barrier function or clotting proteins was not observed in all cases of bleeding. Additionally, fibrin deposition was observed in the heart and lungs of decedent animals but no evidence of DIC was noted, suggesting a unique pathophysiology of radiation-induced coagulopathies. These findings suggest radiation-induced coagulopathies are the result of simultaneous damage to several key organs and biological functions, including the immune system, the inflammatory response, the bone marrow and the cardiovasculature.

Outcomes after drug-coated balloon interventions for de novo coronary lesions in the patients on chronic hemodialysis

The impact of drug-coated balloon (DCB) on hemodialysis (HD) patients with coronary lesions remains unclear. This study aimed to compare outcomes after DCB treatment between HD and non-HD patients with de novo coronary lesions. A total of 235 consecutive patients who electively underwent DCB treatment for de novo coronary lesions were included (HD group: n = 100; non-HD group: n = 135). Angiographic follow-up was performed 6 months after the procedure. Patients were clinically followed up for 2 years. The incidence rates of target lesion revascularization (TLR) and major adverse cardiac events (MACE) were investigated. Diabetes and a history of coronary bypass grafting were more frequent in the HD group than in the non-HD group (69.0% vs. 50.7%, p = 0.007, and 24.0% vs 9.1%, p = 0.013, respectively). The reference diameter and pre-procedural diameter stenosis were greater in the HD group than in the non-HD group (2.49 mm vs. 2.24 mm, p = 0.007, and 65.9% vs. 59.6%, p = 0.015, respectively). Calcification was observed in 65.5% of all lesions, and rotational atherectomy was performed in 30.2% patients. The average diameter of the DCB was 2.51 mm (2.57 mm, HD group vs. 2.47 mm, non-HD group, p = 0.14). Although post-procedural diameter stenosis was similar between the groups, late lumen loss on follow-up angiography was larger in HD patients than in non-HD patients (0.27 mm vs. - 0.03 mm, p = 0.0009). The 2-year rates of freedom from TLR and MACE were lower in HD patients than in non-HD patients [79.3% vs. 91.7%, hazard ratio (HR) 2.76, 95% confidence interval (CI) 1.23-6.77, p = 0.014; and 61.6% vs. 89.4%, HR 4.60, 95% CI 2.30-10.2, p < 0.001, respectively]. In conclusion, the rates of TLR and MACE after DCB treatment were higher in HD patients than in non-HD patients.

Thrombolome and Its Emerging Role in Chronic Kidney Diseases

Patients with chronic kidney disease (CKD) are at an increased risk of thromboembolic complications, including myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism. These complications lead to increased mortality. Evidence points to the key role of CKD-associated dysbiosis and its effect via the generation of gut microbial metabolites in inducing the prothrombotic phenotype. This phenomenon is known as thrombolome, a panel of intestinal bacteria-derived uremic toxins that enhance thrombosis via increased tissue factor expression, platelet hyperactivity, microparticles release, and endothelial dysfunction. This review discusses the role of uremic toxins derived from gut-microbiota metabolism of dietary tryptophan (indoxyl sulfate (IS), indole-3-acetic acid (IAA), kynurenine (KYN)), phenylalanine/tyrosine (p-cresol sulfate (PCS), p-cresol glucuronide (PCG), phenylacetylglutamine (PAGln)) and choline/phosphatidylcholine (trimethylamine N-oxide (TMAO)) in spontaneously induced thrombosis. The increase in the generation of gut microbial uremic toxins, the activation of aryl hydrocarbon (AhRs) and platelet adrenergic (ARs) receptors, and the nuclear factor kappa B (NF-κB) signaling pathway can serve as potential targets during the prevention of thromboembolic events. They can also help create a new therapeutic approach in the CKD population.

The association between platelet indices and cardiovascular events in chronic kidney disease patients without dialysis

PURPOSE

Previous studies have indicated that platelet indices are related to the pathogenesis of cardiovascular diseases (CVD). However, it is unclear which platelet-related indicators are associated with CVD events in patients with chronic kidney disease (CKD) without dialysis.

METHODS

We performed a single-center prospective cohort study involved 1391 CKD patients to explore the relationship between platelet indices and CVD events in CKD patients. A nomogram was generated to predict CVD-free survival after 3 and 5 years of follow-up in terms of the fitted Cox regression model. And the time-dependent receiver-operating characteristic (ROC) curves were applied to evaluate the prediction accuracy of platelet indices on CVD events.

RESULTS

During a median follow-up of 3.41 years, 211 (15.2%) patients experienced CVD events. Results showed that platelet counts (PLT), plateletcrit (PCT), platelet-large cell ratio (P-LCR), and platelet distribution width (PDW) among 5 platelet indices were significantly lower in advanced CKD stages. Cox regression model showed that PLT, PDW, and PCT were associated with CVD events. However, after multivariable-adjusted, low level of PLT, hazard ratio (HR) 0.994 and 95% confidence interval (95% CI 0.989-1.000, p = 0.04), and PDW, HR 0.936 (95% CI 0.878-0.998, p = 0.044) predicted CVD events. The area under the ROC curve (AUC) of platelet indices assessed by time-dependent ROC curve analysis showed that only PLT and PDW were significant for predicting CVD events for 5 years.

CONCLUSIONS

We demonstrated that PLT and PDW among 5 platelet indices were independently associated with CVD events in patients with CKD.

Surgical approach for kidney transplantation under spinal anesthesia

Kidney transplantation is the treatment of choice for patients with end-stage renal disease (ESRD). It has been shown to improve quality of life as well as extending life of patients with ESRD as compared to renal replacement therapy (5-year survival rate of 68% after transplant vs 36% dialysis) (Hart A, Smith JM, Skeans MA. OPTN/SRTR 2015 annual data report: kidney. Am J Transplant 2017;17:21–116). Traditionally, patients undergo general endotracheal tube anesthesia for this surgery. During the COVID-19 pandemic, general anesthesia drugs and airway equipment were in short supply. Additionally, airway manipulation was avoided when possible due to concern for virus spread from aerosolizing procedures (i.e. intubation/extubation). In this case report, we review a 65-year-old female with an ESRD due to hypertension and diabetes that underwent deceased donor kidney transplant under spinal anesthesia. We will further discuss the benefits of spinal anesthesia in renal transplant operations.

Thromboembolic and Bleeding Risk in Atrial Fibrillation Patients with Chronic Kidney Disease: Role of Anticoagulation Therapy

Atrial fibrillation (AF) and chronic kidney disease (CKD) are strictly related; several independent risk factors of AF are often frequent in CKD patients. AF prevalence is very common among these patients, ranging between 15% and 20% in advanced stages of CKD. Moreover, the results of several studies showed that AF patients with end stage renal disease (ESRD) have a higher mortality rate than patients with preserved renal function due to an increased incidence of stroke and an unpredicted elevated hemorrhagic risk. Direct oral anticoagulants (DOACs) are currently contraindicated in patients with ESRD and vitamin K antagonists (VKAs), remaining the only drugs allowed, although they show numerous critical issues such as a narrow therapeutic window, increased tissue calcification and an unfavorable risk/benefit ratio with low stroke prevention effect and augmented risk of major bleeding. The purpose of this review is to shed light on the applications of DOAC therapy in CKD patients, especially in ESRD patients.

Instrumented Posterolateral fusion versus instrumented Interbody fusion for degenerative lumbar diseases in uremic patients under hemodialysis

Background

Advances in hemodialysis have facilitated longer lifespan and better quality of life for patients with end stage renal disease (ESRD). Symptomatic degenerative lumbar diseases (DLD) becomes more common in patients with ESRD. Posterior instrumented fusion remains popular for spinal stenosis combining instability. Only a few sporadic studies mentioned about surgical outcomes in patients with ESRD underwent spine surgeries, but no one discussed about which fusion method was optimal for this kind of patients. In this study, we compared the differences between lumbar posterolateral fusion (PLF) and lumbar interbody fusion (IBF) in uremic patients underwent instrumented lumbar surgeries.

Methods

Between January 2005 and December 2017, ESRD patients under maintenance hemodialysis underwent posterior instrumented fusion for DLD were reviewed. A PLF group and an IBF group were identified. The demographic data was collected using their medical records. Clinical outcomes were evaluated by Oswestry Disability Index (ODI) and the visual analogue scale (VAS); radiographic results were assessed using final fusion rates. Any surgical or implant-related complication was documented.

Results

A total of 34 patients (22 women and 12 men, mean age of 65.4 years) in PLF group and 45 patients (26 women and 19 men, mean age of 65.1 years) in IBF group were enrolled. Both groups had similar surgical levels. The operation time was longer (200.9 vs 178.3 min, p = 0.029) and the amount of blood loss was higher (780.0 vs 428.4 ml, p = 0.001) in the IBF group. The radiographic fusion rate was better in the PLF group but without significant difference (65.2% vs 58.8%, p = 0.356). Seven in the PLF group and ten in the IBF group developed surgical complications (20.5% vs. 22.2%, p = 0.788); three patients in the PLF group (8.8%) and five patients in the IBF group (11.1%) received revision surgeries because of implant-related or wound complications. Comparing to preoperative ODI and VAS, postoperative ODI and VAS obtained significant improvement in both groups.

Conclusions

Successful fusion rates and clinical improvement (VAS, ODI) were similar in IBF and PLF group. Uremic patients underwent IBF for DLD had longer length of operation and higher operative blood loss than underwent PLF.

Incidence and risk factors of colonoscopic post-polypectomy bleeding and perforation in patients with end-stage renal disease

BACKGROUND AND AIMS

Colonoscopic polypectomy in end-stage renal disease (ESRD) patients are at risks of post-polypectomy bleeding and perforation, but evidences are limited. This study aimed to determine the incident polypectomy complications among ESRD patients.

METHODS

In the nationwide ESRD cohort, a propensity score matched case-control study design was conducted to assess risk associated with post-polypectomy bleeding and perforation using the Taiwanese National Health Insurance Research Database from 1997 to 2013 for adults aged 40 years and older; 7011 ESRD and 19 118 non-ESRD patients met the study criteria. A total of 5302 patients in each group were matched for further analyses. The primary endpoint was post-polypectomy bleeding or bowel perforation in 30 days. The secondary endpoint was mortality and length of hospital stay for the bleeding complications requiring hospitalization.

RESULTS

Overall incidences of post-polypectomy bleeding or perforation in patients with ESRD was higher than the non-ESRD group (5.83% vs 1.78%, P < 0.0001) in the matched cohort. High risk of adverse outcomes was associated with ESRD (adjusted odds ratio [aOR], 2.38, 95% confidence interval [CI], 1.85-3.05), female patient (aOR, 1.7, 95% CI, 1.37-2.11), history of acute myocardial infarction (aOR, 1.91, 95% CI, 1.1-3.32), liver disease (aOR, 1.79, 95% CI, 1.37-2.34), diabetes (aOR, 1.45, 95% CI, 1.16-1.82), cancer (aOR, 1.4, 95% CI, 1.09-1.81), inpatient setting (aOR, 13.19, 95% CI, 9.73-17.88), and prior use of clopidogrel (aOR, 1.61, 95% CI, 1.03-2.52) and warfarin (aOR, 2.03, 95% CI, 1.21-3.41).

CONCLUSIONS

End-stage renal disease was associated with approximately twofold higher risk of colonoscopic post-polypectomy bleeding or perforation and should be cautiously performed in this special population cohort.

Cerebro-renal interaction and stroke

Stroke is an event causing a disturbance in cerebral function leading to death and disability worldwide. Both acute kidney injury and chronic kidney disease (CKD) are associated with an increased risk of stroke and cerebrovascular events. The underlying mechanistic approach between impaired renal function and stroke is limitedly explored and has attracted researchers to learn more for developing therapeutic intervention. Common risk factors such as hypertension, hyperphosphatemia, atrial fibrillation, arteriosclerosis, hyperhomocysteinemia, blood-brain barrier disruption, inflammation, etc. are observed in the general population, but are high in renal failure patients. Also, risk factors like bone mineral metabolism, uremic toxins, and anemia, along with the process of dialysis in CKD patients, eventually increases the risk of stroke. Therefore, early detection of risks associated with stroke in CKD is imperative, which may decrease the mortality associated with it. This review highlights mechanisms by which kidney dysfunction can lead to cerebrovascular events and increase the risk of stroke in renal impairment.

Anticoagulation in Patients with End-Stage Renal Disease and Atrial Fibrillation: Confusion, Concerns and Consequences

End-stage renal disease (ESRD) patients have a higher prevalence of diabetes mellitus, hypertension, congestive heart failure and advanced age, along with an increased incidence of non-valvular atrial fibrillation (AF), thereby increasing the risk for cerebrovascular accidents. Systemic anticoagulation is therefore recommended in patients with ESRD with AF to reduce the risk and complications from thromboembolism. Paradoxically, these patients are at an increased risk of bleeding due to great degree of platelet dysfunction and impaired interaction between platelet and endothelium. Currently, CHA2DS2-VASc and Hypertension, Abnormal liver/kidney function, Stroke, Bleeding, Labile INR, Elderly, Drugs or alcohol (HAS-BLED) are the recommended models for stroke risk stratification and bleeding risk assessment in patients with AF. There is conflicting data regarding benefits and risks of medications such as antiplatelet agents, warfarin and direct oral anticoagulants in ESRD patients with AF. Moreover, there is no randomized controlled trial data to guide the clinical decision making. Hence, a multi-disciplinary approach with annual re-evaluation of treatment goals and risk-benefit assessment has been recommended. In this article, we review the current recommendations with risks and benefits of anticoagulation in patients with ESRD with AF.

Platelet Dysfunction Diseases and Conditions: Clinical Implications and Considerations

INTRODUCTION

Platelet diseases and dysfunction are taught early in medical school to all future physicians. Understanding of the coagulation cascade and hemostatic mechanisms has allowed for targeted pharmacological therapies that have been significantly impactful in clinical practice. Platelets are an early participant in hemostasis physiologically and under pathophysiological states.

METHODS

A review of literature involving platelet disfunction.

RESULTS

Various presentations of platelet diseases and dysfunction challenge clinicians and require a firm understanding of normal platelet function, drugs that mediate or modulate platelet effectiveness, and nonpharmacologic etiologies of platelet diseases and dysfunction with corresponding best practice treatment approaches.

CONCLUSION

This review summarizes normal and abnormal states associated with platelets and treatment strategies.

Safety of Dual-Antiplatelet Therapy After Myocardial Infarction Among Patients With Chronic Kidney Disease

Background Although recommended in the guidelines, the safety of chronic P2Y₁₂ inhibitor therapy in patients with chronic kidney disease ( CKD ) after an acute myocardial infarction ( MI ) is not well studied. Methods and Results The TRANSLATE -ACS (Treatment with ADP Inhibitors: Longitudinal Assessment of Treatment Patterns and Events After Acute Coronary Syndrome) study included 11 108 MI patients treated with percutaneous coronary intervention and discharged alive on a P2Y₁₂ inhibitor from 233 US hospitals. We compared rates of GUSTO (Global Use of Strategies to Open Occluded Arteries) severe/moderate bleeding and premature discontinuation of P2Y₁₂ inhibitor by 1 year after MI among patients with varying CKD severity. The majority of MI patients treated with percutaneous coronary intervention had CKD : 42% had stage 2 (mild), 27% had stage 3 (moderate), and 4% had stage ≥4 (severe/end stage). Higher potency P2Y₁₂ inhibitors (prasugrel or ticagrelor) were prescribed at discharge in 39%, 35%, 23%, and 15% ( P<0.01) of patients with stages 1, 2, 3, and ≥4, respectively. One-year GUSTO severe/moderate bleeding rates were higher with each stage of CKD : 1% in patients with CKD stage 1 or no CKD , 2% with an adjusted hazard ratio of 1.61 (95% CI, 1.05-2.35) for CKD stage 2, 4% with an adjusted hazard ratio of 1.92 (95% CI, 1.21-3.02) for CKD stage 3, and 10% with an adjusted hazard ratio of 2.44 (95% CI, 1.40-4.23) for patients with CKD stage ≥4. By 1 year after MI , 16% of patients overall had prematurely discontinued P2Y₁₂ inhibitor therapy; however, this rate was not largely affected by CKD stage. Premature P2Y₁₂ inhibitor-discontinuation rates were higher for patients discharged on higher potency P2Y₁₂ inhibitors in patients with CKD stage ≥2 ( P<0.01). Conclusions CKD severity was associated with a higher bleeding risk among those with acute MI treated with a P2Y₁₂ inhibitor. Patients with more advanced CKD were not significantly more likely than those with less advance CKD to prematurely discontinue P2Y₁₂ inhibitor therapy.

Non-cardiac surgery in patients with coronary artery disease: risk evaluation and periprocedural management

Perioperative cardiovascular complications are important causes of morbidity and mortality associated with non-cardiac surgery, particularly in patients with coronary artery disease (CAD). Although preoperative cardiac risk assessment can facilitate the identification of vulnerable patients and implementation of adequate preventive measures, excessive evaluation might lead to undue resource utilization and surgical delay. Owing to conflicting data, there remains some uncertainty regarding the most beneficial perioperative strategy for patients with CAD. Antithrombotic agents are the cornerstone of secondary prevention of ischaemic events but substantially increase the risk of bleeding. Given that 5-25% of patients undergoing coronary stent implantation require non-cardiac surgery within 2 years, surgery is the most common reason for premature cessation of dual antiplatelet therapy. Perioperative management of antiplatelet therapy, which necessitates concomitant evaluation of the individual thrombotic and bleeding risks related to both clinical and procedural factors, poses a recurring dilemma in clinical practice. Current guidelines do not provide detailed recommendations on this topic, and the optimal approach in these patients is yet to be determined. This Review summarizes the current data guiding preoperative risk stratification as well as periprocedural management of patients with CAD undergoing non-cardiac surgery, including those treated with stents.

Small bowel angioectasia as a marker of frailty and poor prognosis

Background and study aims  This study aimed to establish 5-year survival of patients diagnosed with bleeding small bowel (SB) angioectasia, with the hypothesis that many will suffer deaths relating to comorbidity rather than gastrointestinaI bleeding. Patients and methods  SB capsule endoscopy (SBCE) procedures, performed for suspected SB bleeding or iron deficiency anemia, with angioectasia isolated as the cause of SB bleeding and at least 5 years of follow-up data were isolated (n = 125) along with an age-matched group with "normal" SBCE procedures (n = 125). These were retrospectively analysed with further information on mortality and comorbidity gathered through hospital records. Results  Those with angioectasia had a median age of 72.7 years and comorbidities were common. The 5-year survival was 64.0 % (80/125) compared to 70.4 % (88/125) in those with "normal" SBCE. Those with significant cardiac or vascular comorbidity had a poorer survival (52.9 % (37/70) at 5 years) but anticoagulation/antiplatelets/ number of lesions or requirement endoscopic treatment seemed to make little difference. In those with SB bleeding secondary to angioectasia none of the subsequent deaths were directly attributable to gastrointestinal bleeding. Conclusions  In this cohort, SB angioectasia did not lead to any deaths but the 5-year survival was poor due to those diagnosed often being older and having comorbidities. This would support the hypothesis that a diagnosis of SB bleeding secondary to angioectasia suggests frailty.

Modified regional citrate anticoagulation is optimal for hemodialysis in patients at high risk of bleeding: a prospective randomized study of three anticoagulation strategies

BACKGROUND

Recommended regular saline flushing presents clinical ineffectiveness for hemodialysis (HD) patients at high risk of bleeding with heparin contraindication. Regional citrate anticoagulation (RCA) has previously been used with a Ca²⁺ containing dialysate with prefiltered citrate in one arm (RCA-one). However, anticoagulation is not always achievable and up to 40% results in serious clotting in the venous expansion chamber. In this study, we have transferred one-quarter of the TSC from the prefiltered to the post filter based on RCA-one, which we have called RCA-two. The objective of this study was to compare the efficacy and safety of RCA-two with either saline flushing or RCA-one in HD patients with a high bleeding risk.

METHOD

In this investigator-initiated, multicenter, controlled, prospective, randomized clinical trial, 52 HD patients (77 sessions) were randomized to the RCA-2 and RCA-one group in part one of the trial, and 45 patients (64 sessions) were randomized to the RCA-2 and saline group in part two of the trial. Serious clotting events, adverse events and blood analyses were recorded.

RESULTS

Serious clotting events in the RCA-two group were significantly lower compared with the RCA-one and saline group (7.89% vs. 30.77%, P = 0.011; 3.03% vs. 54.84%, P < 0.001, respectively). The median circuit survival time was 240 min (IQR 240 to 240) in the RCA-two group, was significantly longer than 230 min (IQR 155 to 240, P < 0.001) in the RCA-one group and 210 min (IQR 135 to 240, P = 0.003) in the saline group. The majority of the AEs were hypotension, hypoglycemia and chest tightness, most of which were mild in intensity. Eight patients (20.51%) in the RCA-one group, 4 patients (12.90%) in the saline group and 10 patients (26.31%) in the RCA-two group, P > 0.05.

CONCLUSIONS

Our data demonstrated that the modified anticoagulation protocol was more effective and feasible during hemodialysis therapy for patients at high risk of bleeding.

TRIAL REGISTRATION

GDREC, GDREC2017250H. Registered February 2, 2018; retrospectively registered.

Survival Impact and Clinical Predictors of Acute Gastrointestinal Bleeding in Patients With Bloodstream Infection

PURPOSE

The impact of gastrointestinal bleeding (GIB) on outcomes of patients with bloodstream infection (BSI) has not been studied. We aim to evaluate the risk factors and survival impact of GIB on the outcome of BSI.

MATERIALS AND METHODS

This study was conducted prospectively at National Taiwan University Hospital Yunlin Branch between January 1, 2015, and December 31, 2016. Patients aged ≥18 years for who BSI was confirmed by blood cultures were enrolled and followed for 90 days. Risk factors of GIB were identified by univariable and multivariable logistic regression models. The survival impact of GIB on BSI was evaluated with the Cox proportional hazards model with inverse probability of treatment weighting.

RESULTS

Of the 1034 patients with BSI, 79 (7.64%) developed acute GIB. We identified 5 independent predictors of GIB. Patients with BSI complicated with GIB had an increased 90-day mortality compared to patients without GIB (hazard ratio 1.74, 95% confidence interval: 1.14, 2.65).

CONCLUSIONS

Gastrointestinal bleeding had an adverse impact on the short-term survival in patients with BSI. The clinical predictors may help identify patients who may benefit from active prevention and treatment of GIB.

A prospective, randomized, pilot trial of a polyethylene glycol (PEG)-coated collagen patch (Hemopatch®) for intraoperative hemostasis during deceased donor renal transplant

INTRODUCTION

The objective of this study was to evaluate the safety and feasibility of using a polyethylene glycol (PEG)-coated collagen patch (Hemopatch^®) in patients undergoing deceased donor renal transplant. The primary outcome was the amount of intraoperative estimated blood loss in those patients receiving the patch compared to without. Secondary outcomes were the subjective achievement of hemostasis, perigraft collection, and drop in hemoglobin 48 hours postoperatively.

METHODS

We performed a single-center, prospective, randomized trial. Patients scheduled to undergo deceased donor renal transplant surgery were randomized to receive the PEG-coated patch or standard hemostasis (i.e., electrocautery and clips).

RESULTS

A total of 30 patients were enrolled over 15 months and randomized to receive the PEG-coated patch (n=15) or standard hemostasis (n=15). The mean age was 62.5 years. As determined by the operating surgeon, hemostasis was successfully achieved in all 15 cases using the PEG-coated patch. In the PEG-coated patch group, there was a trend towards less estimated blood loss (237 cc vs. 327 cc; p=0.11) and a lower drop in hemoglobin 48 hours postoperatively (22.27 g/L vs. 29.53 g/L; p=0.09) compared to the standard hemostasis group. Perigraft collection was similar between groups (27% vs. 40%; p=0.43). Subgroup analysis on patients who received anticoagulation therapy revealed no significant difference in blood loss between groups.

CONCLUSIONS

Based on our single-center experience, the PEG-coated patch (Hemopatch^®) is a safe and feasible option to aid hemostasis during deceased donor renal transplant surgery. Hemostasis was successfully achieved in all cases using the PEG-coated patch.

Bleeding after Endoscopic Resection in Patients with End-Stage Renal Disease on Dialysis: A Multicenter Propensity Score-Matched Analysis

Background/Aims

Frequent bleeding after endoscopic resection (ER) has been reported in patients with end-stage renal disease (ESRD). We aimed to evaluate the association and clinical significance of bleeding with ER in ESRD patients on dialysis.

Methods

Between February 2008 and December 2018, 7,571 patients, including 47 ESRD patients on dialysis who underwent ER for gastric neoplasia, were enrolled. A total of 47 ESRD patients on dialysis were propensity score-matched 1:10 to 470 non-ESRD patients, to adjust for between-group differences in variables such as age, sex, comorbidities, anticoagulation use, tumor characteristics, and ER method. Matching was performed using an optimal matching algorithm. For the matched data, clustered comparisons were performed using the generalized estimating equation method. Medical records were retrospectively reviewed. Frequency and outcomes of post-ER bleeding were evaluated.

Results

Bleeding was more frequent in the ESRD with dialysis group than in the non-ESRD group. ESRD with dialysis conferred a significant risk of post-ER bleeding (odds ratio, 6.1; 95% confidence interval, 2.7–13.6; p<0.0001). All post-ER bleeding events were controlled using endoscopic hemostasis except in 1 non-ESRD case that needed surgery.

Conclusions

ESRD with dialysis confers a bleeding risk after ER. However, all bleeding events could be managed endoscopically without sequelae. Concern about bleeding should not stop endoscopists from performing ER in ESRD patients on dialysis.

Long-Term Single-Center Outcomes of Patients With Chronic Renal Dialysis Undergoing Cardiac Surgery

BACKGROUND

The prevalence of dialysis-dependent chronic renal failure (DD-CRF) is growing worldwide. Such patients are exposed to a higher cardiovascular risk because of severe calcification and congestive heart failure caused by volume overload, with poor outcomes. This study aimed to evaluate outcomes of patients with DD-CRF who were undergoing cardiac surgery in a single institution (West German Heart and Vascular Centre Essen, University Hospital Essen, Essen, Germany).

METHODS

A retrospective evaluation of 241 consecutive patients who presented with DD-CRF and were undergoing cardiac-surgery between January 2000 and December 2017 was conducted. End points were major adverse cardiac and cerebrovascular events and long-term survival. Additionally, Cox regression multivariate analysis was performed to detect independent predictors of mortality. Follow-up was 98.3% complete through August 2018.

RESULTS

The mean age of the study cohort was 63 ± 12.2 years, and 65.1% of these patients were male. Congestive heart failure (CHF) was present in 41.5% of patients, 30.7% had a previous myocardial infarction, 9.1% had previous cardiac surgery, and 22.4% needed urgent or emergency surgery. These patients underwent isolated coronary artery bypass grafting (44.8%), isolated procedures other than coronary artery bypass grafting (17.8%), or concomitant procedures (37.3%). Early outcomes reported in-hospital mortality in 10.4%, low cardiac output syndrome in 7.1%, and stroke in 2.1% of patients, respectively. Overall mortality was recorded in 61% of patients at last follow-up. Cox regression multivariate analysis reported age 60 years or older (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.62 to 3.45; P < .001) and CHF (HR, 1.95; 95% CI, 1.37 to 2.78; P < .001) as positive predictors of death and subsequent kidney transplantation (HR, 0.35; 95% CI, 0.20 to 0.59; P < .001) as a negative predictor of death.

CONCLUSIONS

Cardiac surgery in patients with DD-CRF is associated with high morbidity and mortality. Interestingly, overall mortality was mainly not cardiac related, and older patients or those who presented with CHF had the worst life expectancy. However, subsequent kidney transplantation positively affected long-term survival in these patients.

Primary hemostatic function in dogs with acute kidney injury

BACKGROUND

Bleeding tendencies can occur with uremia.

OBJECTIVES

To characterize primary hemostatic function in dogs with acute kidney injury (AKI).

ANIMALS

Ten dogs with International Renal Interest Society AKI grade III or above and 10 healthy controls.

METHODS

Prospective study comparing PCV, platelet count, platelet aggregometry (Multiplate), and von Willebrand factor antigen to collagen binding activity ratio (vWF:Ag:vWF:CBA) in 2 groups of dogs (AKI group versus controls). Buccal mucosal bleeding time was measured in the AKI group only. Data are presented as median [25th, 75th percentile] unless otherwise stated. Significance was set at P < .05.

RESULTS

Mean PCV was significantly lower in the AKI (34.7%; ±SD, 8.8) than in the control (46.1%; ±SD, 3.6; P < .001) group. Platelet count was significantly higher in the AKI (350.5 × 103 /μL [301, 516]) than in the control (241 × 103 /μL [227, 251]; P = .01) group. Collagen-activated platelet aggregometry measured as area under the curve was significantly lower in the AKI (36.9 ± 17.7) than in the control (54.9 ± 11.2; P = .05) group. vWF:Ag:vWF:CBA was significantly higher in the AKI (2.2 [1.9, 2.6]) than in the control (1.1 [1.1, 1.2]; P = .01) group. There was a strong correlation between vWF:Ag:vWF:CBA and creatinine (r = 0.859; P < .001), but no other variables.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with AKI had decreased collagen-activated platelet aggregation and appear to have a type II von Willebrand disease-like phenotype as indicated by the high vWF:Ag:vWF:CBA.

Anticoagulation in Patients With Advanced Chronic Kidney Disease: Walking the Fine Line Between Benefit and Harm

Chronic kidney disease affects more than 3 million Canadians and is highly associated with cardiovascular diseases that require anticoagulation, such as atrial fibrillation and venous thromboembolism. Patients with chronic kidney disease are at a problematic crossroads; they are at high risk of thrombotic conditions requiring anticoagulation and bleeding complications due to anticoagulation. The limited high-quality clinical evidence to guide decision-making in this area further compounds the dilemma. In this review, we discuss the physiology and epidemiology of bleeding and thrombosis in patients with kidney disease. We specifically focus on patients with advanced kidney disease (estimated glomerular filtration rate ≤ 30 mL/min) or who are receiving dialysis and focus on the nephrologist perspective regarding these issues. We summarize the existing evidence for anticoagulation use in the prevention of stroke with atrial fibrillation and provide practical clinical recommendations for considering anticoagulation use in this population. Last, we examine specific scenarios such as the use of a glomerular filtration rate estimating equation and dosing, the use of existing prediction tools for stroke and hemorrhage risk, current patterns of anticoagulation use (including during the dialysis procedure), and vascular calcification with vitamin K antagonist use in patients with chronic kidney disease.

Mechanical versus bioprosthetic valves in patients on dialysis

Background

The aim of this study is to evaluate the outcomes of bioprosthetic versus mechanical valves in patients on dialysis.

Methods

All patients who underwent aortic (AVR) or mitral valve replacement (MVR) at a single institution from 2011-2017 were reviewed. Primary stratification was bioprosthetic versus mechanical valves. The primary outcome was all-cause mortality. Secondary outcomes included hospital readmission, valve reoperation rates and bleeding events. Kaplan-Meier curves were generated and Cox proportional hazards regression models were used for risk-adjustment.

Results

During the study period, 3,969 patients underwent AVR or MVR, of which 97 (2.4%) were on dialysis. In dialysis patients, unadjusted 30-day mortality was comparable between bioprosthetic (12.7%) versus mechanical (5.9%) valves (P=0.31). However, the bioprosthetic group had higher rates of 1-year (40.3% versus 15.2%; P=0.03) and 5-year mortality (67.9% versus 60.7%; P=0.02). Most patients were readmitted within 5 years with no differences between the groups (bioprosthetic 80.3% versus mechanical 100%; P=0.57). There were no valve reoperations in either group at 5 years. The 5-year readmission rate was higher in the mechanical cohort (10.5% versus 53.8%; P=0.05). Risk-adjusted analysis confirmed these findings, where mechanical valves were independently associated with reduced mortality at 1-year and 5-years.

Conclusions

Despite the limited life expectancy of patients on dialysis, mechanical valves have an intermediate term mortality benefit compared to bioprosthetic valves. This comes at the expense of a higher rate of readmission for bleeding. Although valve choice should consider multiple factors, these data suggest that mechanical valve usage in dialysis patients is reasonable.