Cardioprotective effect of intradialytic exercise on left atrial mechanics.

Left atrial (LA) function plays a pivotal role in cardiac performance by modulating left ventricular (LV) function. Impairments in LV function are commonly reported during hemodialysis (HD), but available data describing changes in LA function are limited. There is growing evidence of the cardioprotective effect of intradialytic exercise (IDE) on LV function, but studies analyzing its effect on LA function are scarce. Our aim was to evaluate whether IDE can limit the severity of HD-induced impairment in LA myocardial function. In this prospective, open-label, two-center randomized crossover trial, 56 stable individuals receiving HD participated in 2 HD sessions in random order: standard HD and a session incorporating 30 min of aerobic exercise. LA and LV global longitudinal strains (GLSs) were obtained before and at peak stress of HD (i.e., 30 min before the HD ending). IDE totally eradicated the decline in LA reservoir strain observed during HD (estimated difference: 3.1%, 95% confidence interval: 0.4/5.8, P = 0.02), whereas it did not affect the other components of LA mechanics. A similar result favoring IDE intervention was also demonstrated on GLS changes over the HD procedure (P < 0.001). Between-session differences of changes in GLS and LA reservoir strain were correlated (r = -0.32, P = 0.03). The cardioprotective effect of IDE disappeared in patients with LA enlargement (i.e., LA volume index >34 mL/m2). In conclusion, even a short duration of IDE at moderate intensity is effective in preventing HD-associated decline in LA reservoir function. Further research is needed to explore the long-term benefits of IDE on LA function.NEW & NOTEWORTHY A single bout of intradialytic exercise (IDE) at moderate intensity can prevent the hemodialysis-associated decline in left atrial (LA) function. This was partially explained by the relative preservation of left ventricular systolic function with IDE. Benefits of IDE on LA function were lost in patients with LA dilation. Further studies are needed to explore the mechanisms behind IDE-induced cardioprotection and evaluate the clinical impacts of the repetitive cardioprotective effects of IDE on LA function.

Cardioprotective Effect of Acute Intradialytic Exercise: A Comprehensive Speckle-Tracking Echocardiography Analysis.

SIGNIFICANCE STATEMENT: Hemodialysis (HD) can lead to acute left ventricular (LV) myocardial wall motion abnormalities (myocardial stunning) due to segmental hypoperfusion. Exercise during dialysis is associated with favorable effects on central hemodynamics and BP stability, factors considered in the etiology of HD-induced myocardial stunning. In a speckle-tracking echocardiography analysis, the authors explored effects of acute intradialytic exercise (IDE) on LV regional myocardial function in 60 patients undergoing HD. They found beneficial effects of IDE on LV longitudinal and circumferential function and on torsional mechanics, not accounted for by cardiac loading conditions or central hemodynamics. These findings support the implementation of IDE in people with ESKD, given that LV transient dysfunction imposed by repetitive HD may contribute to heart failure and increased risk of cardiac events in such patients. BACKGROUND: Hemodialysis (HD) induces left ventricular (LV) transient myocardial dysfunction. A complex interplay between linear deformations and torsional mechanics underlies LV myocardial performance. Although intradialytic exercise (IDE) induces favorable effects on central hemodynamics, its effect on myocardial mechanics has never been comprehensively documented. METHODS: To evaluate the effects of IDE on LV myocardial mechanics, assessed by speckle-tracking echocardiography, we conducted a prospective, open-label, two-center randomized crossover trial. We enrolled 60 individuals with ESKD receiving HD, who were assigned to participate in two sessions performed in a randomized order: standard HD and HD incorporating 30 minutes of aerobic exercise (HDEX). We measured global longitudinal strain (GLS) at baseline (T0), 90 minutes after HD onset (T1), and 30 minutes before ending HD (T2). At T0 and T2, we also measured circumferential strain and twist, calculated as the net difference between apical and basal rotations. Central hemodynamic data (BP, cardiac output) also were collected. RESULTS: The decline in GLS observed during the HD procedure was attenuated in the HDEX sessions (estimated difference, -1.16%; 95% confidence interval [95% CI], -0.31 to -2.02; P = 0.008). Compared with HD, HDEX also demonstrated greater improvements from T0 to T2 in twist, an important component of LV myocardial function (estimated difference, 2.48°; 95% CI, 0.30 to 4.65; P = 0.02). Differences in changes from T0 to T2 for cardiac loading and intradialytic hemodynamics did not account for the beneficial effects of IDE on LV myocardial mechanics kinetics. CONCLUSIONS: IDE applied acutely during HD improves regional myocardial mechanics and might warrant consideration in the therapeutic approach for patients on HD.

Global Policy Barriers and Enablers to Exercise and Physical Activity in Kidney Care.

OBJECTIVE: Impairment in physical function and physical performance leads to decreased independence and health-related quality of life in people living with chronic kidney disease and end-stage kidney disease. Physical activity and exercise in kidney care are not priorities in policy development. We aimed to identify global policy-related enablers, barriers, and strategies to increase exercise participation and physical activity behavior for people living with kidney disease. DESIGN AND METHODS: Guided by the Behavior Change Wheel theoretical framework, 50 global renal exercise experts developed policy barriers and enablers to exercise program implementation and physical activity promotion in kidney care. The consensus process consisted of developing themes from renal experts from North America, South America, Continental Europe, United Kingdom, Asia, and Oceania. Strategies to address enablers and barriers were identified by the group, and consensus was achieved. RESULTS: We found that policies addressing funding, service provision, legislation, regulations, guidelines, the environment, communication, and marketing are required to support people with kidney disease to be physically active, participate in exercise, and improve health-related quality of life. We provide a global perspective and highlight Japanese, Canadian, and other regional examples where policies have been developed to increase renal physical activity and rehabilitation. We present recommendations targeting multiple stakeholders including nephrologists, nurses, allied health clinicians, organizations providing renal care and education, and renal program funders. CONCLUSIONS: We strongly recommend the nephrology community and people living with kidney disease take action to change policy now, rather than idly waiting for indisputable clinical trial evidence that increasing physical activity, strength, fitness, and function improves the lives of people living with kidney disease.

CKD complications in kidney-transplanted patients going back to dialysis: impact on patients outcomes.

AIMS: The management of chronic kidney disease (CKD) complications is not always adequate in patients with a failed kidney transplant. We aimed to evaluate the frequency of CKD complications and assess whether they may lead to worse outcomes in this patient population. METHOD: We analyzed 49 kidney transplant recipients with a failed transplant (T+) and matched non-transplanted patients (T-) starting dialysis between 2000 and 2010 in five dialysis centers in France. CKD complications at dialysis initiation, hospitalizations and death were recorded and compared between the two groups. RESULTS: At dialysis initiation, T+ patients were more likely to have bicarbonate < 22 mmol/l (77.6 vs. 22.0%, p < 0.01), phosphate > 1.5 mmol/l (77.6 vs. 59.2%, p = 0.03), arterial blood pressure > 130/80 mmHg (75.5 vs. 93.9%, p = 0.01), body mass index < 23 (59.2 vs. 32.7%, p = 0.01) and albumin < 38 g/l (69.4 vs. 36.7%) than T- patients. T+ patients were hospitalized more frequently in the year following dialysis initiation (40.8 ± 7.0 vs. 16.3 ± 5.3%, log rank p = 0.01) and 5-year survival rate was lower than in T- patients (82.1 ± 6.2 vs. 64.0 ± 7.4%, log rank p = 0.02). However risk of hospitalization and mortality was lesser after adjustments for CKD complications. CONCLUSION: Despite regular follow-up by nephrologists, CKD complications before initiation of dialysis are more frequent in T+ patients than in T- patients. A better management of CKD complications in T+ patients could improve outcomes after dialysis initiation.

Beneficial effects of an intradialytic cycling training program in patients with end-stage kidney disease.

In chronic kidney disease (CKD), oxidative stress (OS) plays a central role in the development of cardiovascular diseases. This pilot program aimed to determine whether an intradialytic aerobic cycling training protocol, by increasing physical fitness, could reduce OS and improve other CKD-related disorders such as altered body composition and lipid profile. Eighteen hemodialysis patients were randomly assigned to either an intradialytic training (cycling: 30 min, 55%-60% peak power, 3 days/week) group (EX; n = 8) or a control group (CON; n = 10) for 3 months. Body composition (from dual-energy X-ray absorptiometry), physical fitness (peak oxygen uptake and the 6-minute walk test (6MWT)), lipid profile (triglycerides (TG), total cholesterol, high-density lipoprotein, and low-density lipoprotein (LDL)), and pro/antioxidant status (15-F2α-isoprostanes (F2-IsoP) and oxidized LDL in plasma; superoxide dismutase, glutathione peroxidase, and reduced/oxidized glutathione in erythrocytes) were determined at baseline and 3 months later. The intradialytic training protocol did not modify body composition but had significant effects on physical fitness, lipid profile, and pro/antioxidant status. Indeed, at 3 months: (i) performance on the 6MWT was increased in EX (+23.4%, p < 0.001) but did not change in CON, (ii) plasma TG were reduced in EX (-23%, p < 0.03) but were not modified in CON, and (iii) plasma F2-IsoP concentrations were lower in EX than in CON (-35.7%, p = 0.02). In conclusion, our results show that 30 min of intradialytic training, 3 times per week for 3 months, are enough to exert beneficial effects on the most sensitive and reliable marker of lipid peroxidation (IsoP) while improving CKD-associated disorders (lipid profile and physical fitness). Intradialytic aerobic cycling training represents a useful and easy strategy to reduce CKD-associated disorders. These results need to be confirmed with a larger randomized study.

Catheter colonization in acute renal failure patients: comparison of central venous and dialysis catheters.

BACKGROUND: Little is known about vascular access infections in patients with acute renal failure. METHODS: We prospectively compared infection rates of dialysis catheters (DCs) and central venous catheters (CVCs) in patients in the intensive care unit treated with renal replacement therapy for acute renal failure. The same insertion and maintenance procedures were used for CVCs and DCs. To circumvent the allocation bias caused by severity of patient condition, only patients with both types of catheters were included. RESULTS: A total of 150 CVCs and 130 DCs were analyzed in 99 patients with a mean Simplified Acute Physiology Score II of 67 +/- 21. The major cause of acute renal failure was sepsis (62%). Hospital mortality was 62%. Mean catheter duration was shorter for DCs (6.7 +/- 4.4 days) than CVCs (7.8 +/- 4.9 days; P = 0.03). There was no difference between CVCs and DCs in cumulative incidence of catheter colonization (quantitative catheter cultures > or = 10(3) colony-forming units/mL; 4.7% versus 6.2%; P = 0.58) or incidence density of catheter colonization per 1,000 catheter days (5.9 versus 9.1; P = 0.44, respectively). There also was no difference between CVCs and DCs in cumulative incidence and incidence density regardless of whether catheters were placed at the internal jugular (P = 0.34 and P = 0.23) or femoral site (P = 0.57 and P = 0.80), respectively. Three cases of CVC-related bacteremia (the same microorganism responsible for both catheter colonization and blood culture result) were recorded, but none with DC use. CONCLUSION: When severity of patient condition is controlled for, epidemiological characteristics of colonization in CVCs and DCs are similar if similar infection control measures are used for insertion and maintenance.