Diastolic dysfunction in asymptomatic hemodialysis patients in the light of the current echocardiographic guidelines.

The prevalence of the left ventricular hypertrophy (LVH) is very high in end-stage renal disease treated by hemodialysis. Diastolic dysfunction is a frequent consequence and leads to the development of heart failure with preserved ejection fraction. New American/European echocardiographic guidelines for the assessment of diastolic function simplified the evaluation and were published recently. The aim of this study was to reveal if the new guidelines stratify asymptomatic hemodialysis patients by the levels of brain-natriuretic peptide (BNP). A cohort of 46 patients hemodialyzed in one center with the lack of overt heart failure, systolic dysfunction, arrhythmia or significant valvular disease were examined by echocardiography before and after a single hemodialysis and blood samples for BNP analysis were drawn at both occasions. The LVH was present in 53% of patients, concentric remodeling in another 17%. Higher indexed left ventricular mass was related to higher BNP levels (r = 0.58, p = 0.0001). Before hemodialysis, diastolic dysfunction was present in 61%: grade 1 in 25%, grade 2 in 21% and grade 3 in 8%. The higher grade of diastolic dysfunction was associated with the incremental increase of BNP. The post-dialysis echocardiography did not allow the assessment of diastolic function in as many as 37% of patients. Our study has shown that the application of the current guidelines for the assessment of diastolic function based on simple four criteria differentiate hemodialysis symptomless patients with preserved systolic function according to BNP levels. BNP levels also rose together with the left ventricular mass. The ratio E/e' medial seemed to be a better predictor of increased BNP than E/e' lateral or E/e' averaged.

Decrease of muscle strength in vascular access hand due to silent ischaemia.

BACKGROUND:: Creation of vascular access leads to considerable local haemodynamic changes with decreased hand perfusion. Distal limb tissues then represent a model of hand ischaemia effect on muscles. The aim of our study was to investigate how the presence of vascular access influences the hand muscle strength in end-stage renal disease patients. METHODS:: We included 52 chronically haemodialysed patients with upper limb access without clinical signs of hand ischaemia. Muscle strength was evaluated by dynamometry. Finger pressure was measured on the second and fourth fingers and averaged for further analysis. Thenar tissue oxygenation (rSO2) was analysed using near-infrared spectroscopy. All examinations were performed in both the hands. Basic laboratory analysis was added. Data were processed with unpaired t-test and correlation analysis. RESULTS:: Hands with dialysis access had lower values of handgrip strength (54.2 ± 29.1 lbs vs 48.6 ± 23.4 lbs, p = 0.0006), systolic finger pressure (127.1 ± 32.0 mmHg vs 101.4 ± 31.6 mmHg, p < 10-8) and of thenar rSO2 (45.8% ± 12.9% vs 42.5% ± 13.3%, p = 0.002). Muscle strength (handgrip) was directly related to the thenar oxygenation ( r = 0.36; p = 0.014) and to the finger systolic pressure ( r = 0.38; p = 0.007) on the access extremity. On the extremity without dialysis access, handgrip strength was inversely related to patient's age ( r = -0.41, p = 0.003), dialysis vintage ( r = -0.32, p = 0.02) and red cell distribution width ( r = -0.37, p = 0.01). CONCLUSION:: The presence of dialysis access leads to the decrease of finger pressure, oxygenation, and also muscle strength even in the absence of clinically overt hand ischaemia. All these parameters are interrelated. This study underlines the consequences of inadequate muscle perfusion.

Low Cerebral Oxygenation Is Associated with Cognitive Impairment in Chronic Hemodialysis Patients.

BACKGROUND/AIMS: High rates of cognitive impairment (CI) are an alarming problem in patients undergoing chronic hemodialysis (HD). Its pathophysiology remains unclear and there are indications that brain ischemia might be one of the key causes. Cerebral tissue oxygenation, as measured by near-infrared spectroscopy, is known to be decreased in HD patients. However, it is unknown whether CI is associated or not associated with lower cerebral oxygenation in these patients. The primary aim of our study was to probe this possible association. Our secondary aim was to assess other factors possibly related to cerebral ischemia and CI. METHODS: Thirty-nine patients treated by chronic HD were included in this cross-sectional study. All measurements were performed before the initiation of an HD session. The Montreal Cognitive Assessment (MoCA) was administered according to published recommendations. Regional saturation of oxygen (rSO2) of the left frontal lobe was measured using the INVOS 5100C device. Basic medical history and laboratory data were recorded, and handgrip strength was analyzed. We used the unpaired t test to compare the rSO2 and other variables between cognitively normal patients (MoCA score ≥26) and those who displayed CI (MoCA score <26). Multiple linear regression analysis was used to adjust for principal confounders. RESULTS: Cognitively impaired patients had lower brain rSO2 values compared to cognitively normal patients (48 ± 9 vs. 57 ± 10%, p = 0.01). Among other variables, higher red cell distribution width (15.8 ± 1.9 vs. 13.8 ± 1.6%, p = 0.01) and lower hand grip strength (49.2 ± 23.3 vs. 99.3 ± 31.4 lbs, p < 0.001) also displayed a significant association with CI. The relation between rSO2 and MoCA score was significant after adjustment for age and gender (p = 0.007). CONCLUSION: Decreased brain oxygenation is associated with weaker cognitive performance in patients undergoing chronic HD. Further understanding the causes of cerebral ischemia in HD patients could lead to the prevention of cognitive decline in this population.