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Background: Patients with chronic kidney disease (CKD) are less likely to be submitted to coronary artery bypass grafting (CABG) then clinical medical treatment based on the potential high risk of mortality. However, whether patients on maintenance dialysis who underwent an elective CABG experience high hospital- and long-term mortality is still debatable. Methods: This is a prospective observational study that evaluated patients who underwent elective CABG. Three groups were compared: reference (n = 167, estimated glomerular filtration rate [eGFR] ≥60 mL/min/1.73 m2), CKD3–4 (n = 84, eGFR 15–59 mL/min/1.73 m2), and maintenance hemodialysis (n = 31). Demographic, clinical, biochemical, fluid balance data, and Sequential Organ Failure Assessment (SOFA) scores were assessed daily for the same observer from day 1 (surgery) to hospital discharge. Results: The main outcomes were in-hospital and 1-year mortality. Patients aged 63 ± 10, 63 ± 8, and 65 ± 6 years old, in reference, CKD3–4, and dialysis groups, respectively (p = 0.605). Patients from the reference group had a lower prevalence of diabetes (p = 0.010) and hypertension (p = 0.021). SOFA scores were higher in CKD3–4 and dialysis groups (p = 0.001), though this difference disappeared without the renal component (p = 0.326). In-hospital mortality (n = 17) was similar across groups (p = 0.955). There was no difference in 1-year mortality among groups even after adjustments for age, diabetes, intraoperative blood loss, and time on ventilation. Conclusions: CABG short-term mortality seems not to be greater among selected patients on maintenance dialysis. A multidisciplinary team has been helping cardiologists and cardiac surgeons in the decision-making process regarding the best approach in coronary artery disease, and CABG should be considered a worthy therapeutic option.

Background: Patients undergoing maintenance hemodialysis (HD) exhibit increased levels of uremic toxins, which are associated with poor outcomes. Recently, new dialysis membranes have allowed clearance of solutes with higher molecular weight, without significant albumin losses high-retention-onset-HD (HRO-HD). Methods: Prospective crossover trial, in which 16 prevalent patients switched from high-flux HD (HF-HD) to online hemodiafiltration (olHDF) and HRO-HD for 4 weeks. The following variables were evaluated: pre- and post-dialysis serum concentrations of albumin, urea, phosphate (P), beta-2 microglobulin (β2M), and total mass (TM) extraction and dialyzer clearance of urea, P, and β2M. Results: Comparing HF-HD, olHDF, and HRO-HD, respectively, there were no differences regarding pre-dialysis serum concentrations of albumin (3.94 ± 0.36, 4.06 ± 0.22, and 3.93 ± 0.41 g/dL, p = 0.495), urea (166 ± 29, 167 ± 30, and 164 ± 27 mg/dL, p = 0.971), P (4.9 ± 2.1, 5.2 ± 1.6, and 4.9 ± 2.1 mg/dL, p = 0.879), and β2M (31.3 ± 7.1, 32.6 ± 8.6, and 33.7 ± 5.9 µg/mL, p = 0.646). β2M clearance was significantly lower in HF-HD in comparison to both olHDF and HRO-HD: 43 (37–53) versus 64 (48–85) mL/min, p = 0.013, and 69 (58–86) mL/min, p = 0.015, respectively. Post-dialysis β2M serum concentration was higher in HF-HD in comparison to olHDF and HRO-HD: 11.6 (9.6–12.4) vs. 5.7 (4.5–7.0) µg/mL, p = 0.001, and 5.6 (5.3–7.6) µg/mL, p = 0.001, respectively. TM extraction of urea, P, and β2M were similar across the 3 dialysis modalities. Conclusions: olHDF and HRO-HD were superior to HF-HD regarding β2M clearance, leading to lower post-dialysis β2M levels.

Background/Aims: Peritoneal dialysis (PD) has gained interest over the last decade as a viable option for early start dialysis. It is still unknown if shorter break-in periods and less time for proper patient evaluation and training could influence technique survival in comparison to planned-start PD. Methods: A prospective and observational study that compared technique survival in a cohort of patients who started either early or planned PD. Early start PD was defined as break-in period from 3 to 14 days with no previous nephrologist follow-up or patient training. Results: A total of 154 patients were included (40 as early start PD), followed by a median time of 381 days. Comparing early vs. planned-start PD, groups were similar concerning age 56 (40; 70) vs. 48 (32; 63) years, p=0.071, body mass index (BMI) 23.3 ± 4.2 vs. 23.8 ± 4.0 kg/m2, p=0.567 and male gender (60 vs. 48%, p=0.201), respectively. Comparing early vs. planned-start groups, there were no differences regarding PD dropout for peritonitis (7.5 vs. 11.4%, p=0.764), catheter dysfunction (12.5 vs. 17.5%, p=0.619) and patient burnout (0 vs. 4.4%, p=0.328), respectively. Less patients in early start group quit PD for peritoneal membrane failure in comparison to planned-start group (2.5 vs. 16.7%, p=0.026). In multivariate cox-regression analysis, the only factors independently associated with technique failure were BMI> 25 kg/m² (p=0.033) and Diabetes Mellitus (p=0.013), whereas no differences regarding early vs. planned-PD start were observed (p=0.184). Conclusion: Despite the adverse scenario for initiating dialysis, early start PD had similar outcomes in comparison to planned-start PD in long-term follow-up.

Background: Conventional hemodialysis (HD) is associated with dialysis-induced hypotension (DIH) and ineffective phosphate removal. As the main source of extracellular fluid removed during HD are the legs, we sought to reduce DIH and increase phosphate removal by using cycling and pneumatic compression, which would potentially provide higher venous return, preserving central blood flow and also offering more phosphate to the dialyzer. Methods: We evaluated 21 patients in a randomized crossover fashion in which each patient underwent 3 different HD: control; cycling exercise during the first 60 min; and pneumatic compression during the first 60 min. Data obtained included bioelectrical impedance, hourly blood pressure measurement, biochemical parameters, and direct quantification of phosphate through the dialysate. DIH was defined as a drop in mean arterial pressure (MAP) ≥20 mm Hg. Results: There was no difference in the ultrafiltration rate (p = 0.628), delta weight (p = 0.415), delta of total, intra and extracellular body water among the control, cycling, and pneumatic compression (p = 0.209, p = 0.348, and p = 0.467 respectively). Delta MAP was less changed by pneumatic compression when compared to control, cycling, and pneumatic compression respectively (-4.7 [-17.2, 8.2], -4.7 [-20.5, -0.2], and -2.3 [-8.1, 9.0] mm Hg; p = 0.021). DIH occurred in 43, 38, and 24% of patients in control, cycling, and pneumatic compression respectively (p = 0.014). Phosphate removal did not increase in any intervention (p = 0.486). Higher phosphate removal was dependent on ultrafiltration, pre dialysis serum phosphate, and higher parathyroid hormone. Conclusion: Pneumatic compression during the first hour of dialysis was associated with less DIH, albeit there was no effect on fluid parameters. Neither exercise nor pneumatic compression increased phosphate removal.

Background: Diuretics are widely used in patients with chronic kidney disease (CKD). While thiazide-like diuretics limit urinary calcium excretion, loop diuretics (LD) promote calcium wasting, which might facilitate the development of secondary hyperparathyroidism (HPT2). We sought to investigate, in CKD patients not on dialysis, the influence of either hydrochlorothiazide (Hydro) or furosemide (Furo) on circulating parathyroid hormone (PTH) and whether such actions are determined by the effects of these compounds on calcium excretion. Methods: Electronic charts of all nephrology outpatients (CKD stages 2-5) who were given Hydro or Furo were included. We assessed estimated glomerular filtration rate (eGFR), biochemical parameters and 24-hour calcium excretion. Hyperparathyroidism was defined as PTH >65 pg/ml. Results: Out of 275 patients, 108 (29%) were taking Hydro and 167 (61%) Furo. Patients on Hydro were younger, mostly female and had higher eGFR. The median 24-hour urinary calcium excretion in the overall cohort was 41 (22, 76), being lower in Furo than in Hydro patients (37 (16, 68) vs. 47 (26, 88) mg/24 h, respectively, p = 0.016). Logistic regression showed that, after adjustment for eGFR, calcium excretion rate was found not to increase the risk ratio for HPT2, whereas Furo was a strong predictor of HPT2. Conclusion: Furo increased the risk of HPT2 among CKD patients compared to Hydro. This effect was independent of eGFR or calcium excretion. The use of LD in CKD, currently preferred in advanced stages, should be reappraised.

Background: Cardiovascular disease is an important cause of death in patients on dialysis. Peripheral arterial disease (PAD) is a prognostic factor for cardiovascular disease. The ankle brachial index (ABI) is a noninvasive method used for the diagnosis of PAD. The difference between ABI pre- and post-dialysis had not yet been formally tested, and it was the main objective of this study. Methods: The ABI was assessed using an automated oscillometric device in incident patients on hemodialysis. All blood pressure readings were taken in triplicate pre- and post-dialysis in three consecutive dialysis sessions (times 1, 2, and 3). Results: One hundred and twenty-three patients (85 men) aged 53 ± 19 years were enrolled. We found no difference in ABI pre- and post-dialysis on the right or left side, and there was no difference in times 1, 2, and 3. In patients with a history of PAD, the ABI pre- versus post-dialysis were of borderline significance on the right side (p = 0.088). Conclusion: ABI measured pre- and post-dialysis presented low variability. The ABI in patients with a history of PAD should be evaluated with caution. The applicability of the current method in predicting mortality among patients on hemodialysis therefore needs further investigation.

Obstructive sleep apnea (OSA) is common among patients on maintenance hemodialysis. However, the factors associated with the origin of OSA as well as the cardiovascular consequences in this population are not completely understood. We evaluated, by standard overnight polysomnography, 24-hour ambulatory blood pressure (BP) monitoring and echocardiography in 30 patients (14 males, age 34 ± 11 years, BMI 23.2 ± 5.2) – 15 on short daily hemodialysis (SDH) and 15 matched patients on conventional hemodialysis (CHD). The hemodialysis dose (standard Kt/V) was higher in patients on SDH than on CHD (p = 0.001). OSA (apnea-hypopnea index >5 events/h) was present in 13 patients (43%). Patients with OSA were predominantly males (77 vs. 44%), presented a higher BMI (25.5 ± 6.2 vs. 21.5 ± 3.6), a larger neck circumference (38 ± 1 vs. 34 ± 1 cm) and a lower Kt/V (2.6 ± 0.3 vs. 2.2 ± 0.1) than patients with no OSA (p < 0.05). Neck circumference and lower Kt/V were independently associated with OSA on multivariate analysis. No patient with Kt/V >2.5 (n = 10) presented OSA. On the other hand, hypertensive patients with OSA needed more BP control pills (p = 0.03). Despite similar BP control, patients with OSA presented a higher interventricular septum thickness (11.5 ± 0.5 vs. 9.9 ± 0.3 mm; p = 0.011). In conclusion, among patients on maintenance hemodialysis, the traditional risk factors for OSA are present and interact with hemodialysis efficiency. Among these patients, OSA is associated with difficult BP control and heart remodeling suggesting that OSA may contribute to poor cardiovascular outcome.