Evaluation of aortic arch calcification in hemodialysis patients

BACKGROUND: In the general population, aortic arch calcification (AAC) is related to cardiovascular (CV) disease. Vascular calcifications are common findings in dialysis patients; therefore, we carried out a retrospective study evaluating which risk factors are associated to AAC in stable hemodialysis (HD) patients. METHODS: Standard posterior-anterior chest radiographs, performed the day after the midweek HD session in 132 patients (mean age 65 +/- 12 yrs) who had been on renal replacement therapy (RRT) for 33 months (range 1-471), were analyzed. Cardiothoracic ratio (CTR) was also calculated. RESULTS: AAC was detected in 51% of patients. They were older (68 +/- 8 vs. 62 +/- 14 yrs; p = 0.003), were on RRT for longer (51 (range 2-471) vs. 22 (range 1-195) months; p = 0.0001), had greater CTR (54 (32-71) vs. 50% (40-65); p = 0.034) and higher prevalence of peripheral vascular disease (PVD) (40 vs. 17%; p = 0.049), whilst body weight was lower (62 +/- 14 vs. 68 +/- 14 kg; p = 0.04) than those without AAC. On the contrary, sex, diabetes frequency, smoking habit, history of hypertension and hyperphosphatemia, cerebrovascular and ischemic heart disease (IHD), blood pressure (BP) and antihypertensive therapy, lipids, albumin, degree of anemia, calcium, phosphate and their product were no different between the two groups. Logistic regression analysis showed that age (odds ratio (OR) 1.069 95% confidence interval (95% CI) 1.02-1.11; p = 0.003), length of time on RRT (OR 1.02 95% CI 1.01-1.03; p = 0.0002), calcium-phosphate product (OR 1.03 95% CI 1.007-1.07; p = 0.016), systolic BP (OR 1.03 95% CI 1.005-1.06; p = 0.02) and PVD (OR 3.08 95% CI 1.17-8.06; p = 0.02) were independently associated to AAC. CONCLUSIONS: We conclude that AAC is related to atherosclerosis and to renal failure-related CV risk factors. A careful evaluation of a frequently performed investigation is useful in CV disease risk stratification in HD patients.     

Acute effects of intermittent hemodialysis and sustained low-efficiency hemodialysis (SLED) on the pulmonary function of patients under mechanical ventilation

The effects of hemodialysis (HD) on pulmonary function are still controversial. The objective of this study was to evaluate the effect of intermittent hemodialysis (IHD) and sustained low-efficiency dialysis (SLED) on the respiratory mechanics of ICU patients under invasive mechanical ventilation. We prospectively studied 31 patients. Laboratory and respiratory evaluation (static and dynamic compliance and resistance) was performed pre- and post-HD. Forty HD sessions were studied and grouped in: SLED (n = 17; Qa = 200-250 mL/min, Qd = 300 mL/min) and IHD (n = 23; Qa = 250-300 mL/min, Qd = 500 mL/min). There was no difference between the groups according to age, gender, comorbidities, APACHE II, and cause of mechanical ventilation, but pre-HD, patients in the IHD group had higher levels of plasma creatinine (5.4 +/- 2.0 vs. 4.2 +/- 1.3 mg/dL, p = 0.048) and platelets (286 +/- 186 vs. 174 +/- 95 10(3)/mm(2), p = 0.032) and lower arterial pH (7.37 +/- 0.07 vs. 7.42 +/- 0.05, p = 0.02). The efficiency of the treatment was similar (p > 0.05) with both types of HD regarding fluid removal, urea reduction rate, and decrease in plasma creatinine. Pre-HD, the ventilatory conditions of both groups were similar (p > 0.05) except for pressure support ventilation and airflow resistance. There were no changes (pre- versus post-HD p > 0.05) induced either by IHD or SLED in the ratio PaO(2)/FiO(2) or in any measured ventilatory parameter. In conclusion, neither IHD nor SLED modifies the pulmonary function of patients under mechanical ventilation.     

Leukopenia and thrombocytopenia in hemodialysis patients with hepatitis B or C virus infection and non-hemodialysis patients with hepatitis cirrhosis

AIMS: To investigate the relation of leukopenia and thrombocytopenia in hemodialysis (HD) patients with hepatitis C virus (HCV) infection. MATERIALS AND METHODS: The study included 86 HD patients with hepatitis B surface antigen-negative and hepatitis C antibody-negative, 28 HD patients with hepatitis C antibody-positive, 22 HD patients with hepatitis B surface antigen-positive, 78 non-HD patients with hepatitis B-induced liver cirrhosis and 38 non-hemodialysis patients with hepatitis C-induced liver cirrhosis. The following parameters were checked: anti-HCV, hepatitis B surface antigen, hemoglobin, hematocrit, white blood cells, platelets, calcium, phosphate, iron, ferritin, albumin, globulin, aspartate transaminase (AST), alanine transaminase (ALT) and C-reactive protein. The history of blood transfusions, medications, erythropoietin doses and adequate dialysis (KTNV) for 6 consecutive months was also recorded from charts. RESULTS: The HD patients with positive serum anti-HCV and non-HD patients with hepatitis B- or C-induced liver cirrhosis had higher prevalences of leukopenia (39.3%, 43.6% and 50% vs. 15.1%; p < 0.001) and thrombocytopenia (67.9%, 89.7% and 81.6% vs. 34.9%: p < 0.001) than HD patients with serum anti-HCV(-)HbsAg(-). The WBC (4,432 +/- 1,394, 4,792 +/- 2,263 and 4,624 2,446 vs. 5,590 +/- 1,500/mm3; p < 0.001) and platelet counts (140 +/- 45, 80 +/- 50 and 89 +/- 65 vs. 186 +/- 62 x 10(3)/mm3; p < 0.001) of HD patients with positive serum anti-HCV and non-HD patients with hepatitis B- or C-induced cirrhosis were also lower than HD patients without anti-HCV antibody. The liver cirrhosis patients had more thrombocytopenia than the HD patients with anti-HCV(+). The WBC and platelet counts did not vary between HD patients with HbsAg(+) and HD patients with anti-HCV(-)HBsAg(-). The durations of HD, hepatitis and liver cirrhosis were not related to the leukopenia or thrombocytopenia (p > 0.05). CONCLUSIONS: HCV infection associated with leukopenia and/or thrombocytopenia in HD patients is as common as in non-HD patients with liver cirrhosis. This may be due to the direct effect of hemopoiesis rather than the hyperspleenism of liver cirrhosis patients. There is a need for further prospective investigation to ascertain the clinical significance of leukopenia and thrombocytopenia in HD patients with anti-HCV(+). The prevalence of leukopenia and thrombocytopenia was higher in HD patients with hepatitis C than in HD patients with hepatitis B and HD patient without hepatitis.     

Reduction in erythropoietin doses by the use of chronic intravenous iron supplementation in iron-replete hemodialysis patients

BACKGROUND: Iron deficiency is the most common cause of suboptimal response to recombinant human erythropoietin (rHuEPO) in chronic hemodialysis (HD) patients. Iron supply can correct this situation, however, optimal dosage, route of administration, and monitoring of iron status during rHuEPO therapy in maintenance HD patients remains controversial. METHODS: We conducted a 12-month intravenous iron substitution trial in 149 iron-replete chronic HD patients receiving subcutaneous rHuEPO therapy. The available iron pool was maintained with 100 mg iron every 2 weeks or 1 month depending on serum ferritin and transferrin saturation levels, the rHuEPO dosage titrated depending on hematocrit (Hct) levels. RESULTS: After 12-month protocol, the Hct increased (28.7 +/- 4.1 vs 27.7 +/- 2.6, p = 0.003), rHuEPO requirement reduced 25% (46.1 +/- 28.9 vs 61.5 +/- 67.8 U/kg/week, p = 0.006), serum ferritin increased (1,383 +/- 727 vs 930 +/- 857 ng/ml, p < 0.001), so did the transferrin saturation (36.1 +/- 12.7 vs 27.5 +/- 12.8%, p < 0.001). The serum albumin decreased slightly but reached statistical significance (4.1 +/- 0.48 vs 4.2 +/- 0.36 g/dl, p = 0.006), so did the cholesterol levels (166 +/- 41 vs 173 +/- 38 mg/dl, p = 0.044) and pre-dialysis creatinine (11.3 +/- 2.3 vs 11.5 +/- 2.4 mg/dl, p = 0.015). Besides, the iPTH levels did not interfere with the rHuEPO dosage reduction and Hct increment in our patients. CONCLUSION: We conclude that maintaining high levels of serum ferritin and transferrin saturation could further reduce the requirement of rHuEPO in chronic HD patients, but the long-term effect of iron overloading to patients' nutritional status must be further evaluated in contrast to the economic saving.     

Perioperative clinical predictors of atrial fibrillation occurrence following coronary artery surgery.

OBJECTIVE: Atrial fibrillation (AF) is the most frequently encountered arrhythmic complication associated with coronary surgery. The aim of this paper was then to identify the clinical predictors of post-CABG AF occurrence. METHODS: 150 consecutive patients were included in this study and divided into two groups according to the absence (SR group, 104 male and 22 female, age 58.4+/-8.8 years) or presence (AF group, 23 male and 1 female, age 65.4+/-6.3 years) of post-CABG AF. Forty-seven perioperative variables were considered. RESULTS: After univariate analysis, advanced age (SR vs. AF: 58.4+/-8.8 vs. 65.4+/-6.3, P < 0.001), an increased BMI (SR vs. AF: 26.1+/-2.7 vs. 27.4+/-2.5, P = 0.026), a prior history of paroxysmal AF (SR vs. AF: 3.2% vs. 16.7%, P = 0.028), left atrial enlargement (SR vs. AF: 21.1% vs. 70.8%, P < 0.001) and a more severe coronary artery disease (CAD) (SR vs. AF: no. of diseased vessels: 2.42+/-0.7 vs. 2.91+/-0.3, P = 0.001; three-vessel CAD (54.1% vs. 91.3%, P = 0.002) were the only factors that statistically differed between the groups. Multivariate logistic regression analysis identified left atrial enlargement (P < 0.0001), a prior history of paroxysmal AF (P = 0.007) and a more severe CAD (P = 0.0047) to be independent correlates for AF. CONCLUSIONS: Post-CABG AF seems to require a well definite anatomical and electrical substrate that is generated by increased left atrial dimensions, a greater extension of coronary lesions and a possible electrical remodeling consequent to prior repetitive episodes of paroxysmal AF.     

Intravenous ascorbic acid in hemodialysis patients with functional iron deficiency: a clinical trial

BACKGROUND: Hemodialysis (HD) patients with functional iron deficiency (FID) often develop resistance to recombinant human erythropoietin (rHuEpo). In these patients, iron therapy may be a hazard, leading to iron overload and consequently to hemosiderosis. Recent studies suggest that intravenous ascorbic acid (IVAA) may circumvent rHuEpo resistance. The aim of our study was to show the effects of IVAA on FID and whether this results in a better correction of anemia in HD patients with stable hemoglobin (Hb) concentration and FID. METHODS: Twenty-seven HD patients with serum ferritin >300 microg/l, transferrin saturation (TS) <20% and hemoglobin (Hb) <10 g/dL were selected andrandomly divided into two groups to enter a cross-over trial with IVAA. In group I IV vitamin C 500 mg was administered three times a week for three months and discontinued in the next three months of the study. Vitamin C was not given the first three months in group II (control group, first three months of the study), who then received 500 mg IV three times a week for the next three months. RESULTS: Hb and TS% significantly increased (baselines vs 3 months, Hb 9.2 +/- 0.2 vs 10.0 +/- 0.3 g/dL, TS% 17.5 +/- 0.6 vs 25.7 +/- 1.7, respectively p < 0.01 and p <0.001) in group I after three months; ferritin fell significantly from 572 +/- 40 to 398 +/- 55 microg/L (p<0.004). Ten patients completed the study: mean Hb and TS% fell significantly (3 months vs final, Hb 9.9 +/- 0.3 vs 8.9 +/- 0.2 g/dL, TS% 25.1 +/- 1.2 vs 19.1 +/- 1.1, respectively p < 0.01 and p <0.001), while mean ferritin did not change. Mean Hb, ferritin and TS% remained unchanged in group II after three months. Hb and TS% mean values rose significantly (3 months vs final, Hb 9.0 +/- 0.2 vs 9.9 +/- 0.2 g/dl, TS% 18.4 +/- 1.0 vs 27.0 +/- 1.0, respectively p < 0.005 and p <0.001), and ferritin markedly decreased from 450 +/- 50 to 206 +/- 24 microg/L (p < 0.001) at the end of the study. The rHuEpo dose was kept unchanged throughout the study. Differences were analyzed after three months. Mean Hb rose (0.8 +/- 0.2 g/dL) in group I but dropped (-0.1 +/- 0.1 g/dL) (p< 0.009) in group II. Ferritin dropped in both groups (group I vs group II, -173 + /-48 vs - 33 +/- 21 microg/L) (p < 0.01) while TS% increased (group I vs group II, 8.2 +/- 1.5 vs 0.4 +/- 0.7) (p < 0.001). CONCLUSION: IVAA may partially correct FID and consequently help rHuEpo hyporesponsive anemia.     

Effects of optimized heart failure therapy and anemia correction with epoetin beta on left ventricular mass in hemodialysis patients

BACKGROUND: In chronic hemodialysis (HD) patients, the presence and degree of left ventricular hypertrophy (LVH) correlates with mortality. Previous studies have shown that interventions, such as anemia correction or treatment of hypertension and/or chronic heart failure (CHF), can result in moderate regression of LVH. The primary objective of our study was to investigate the effects of a multi-interventional treatment strategy on LVH in HD patients. METHODS AND RESULTS: In a series of 202 consecutive HD patients, we combined optimized CHF therapy, including beta-blockers (BB), ACE inhibitors and angiotensin receptor blockers (ARBs), to target doses with full anemia correction by epoetin beta (hemoglobin (Hb) target males 14.5 g/dl, females 13.5 g/dl). Serial echocardiograms were recorded every 3-6 months. Mean follow-up was 3.4 +/- 1.2 years. Mean Hb at baseline was 11.4 +/- 1.4 vs. 14.6 +/- 1.6 g/dl (p < 0.001) at study end. There was a significant reduction in left ventricular mass index (LVMI, 159 +/- 65 vs. 132 +/- 46 g/m2 (p < 0.001)), an improvement in left ventricular ejection fraction (LVEF, 60 +/- 15 vs. 66 +/- 12% (p < 0.01)) and in NYHA class (2.8 +/- 0.76 vs. 1.96 +/- 0.76 (p < 0.01)) from baseline to follow-up in the overall study population. In a subgroup of 70 patients, LVMI returned to normal (169 +/- 33 vs. 114 +/- 14 g/m2 (p < 0.001)) after 1.4 +/- 1 years. CONCLUSIONS: Our study shows that optimized CHF therapy, in combination with anemia correction to normal Hb targets, results in a significant reduction of LVH, an increase in LVEF and an improvement in NYHA class. Moreover, in contrast to previous studies, our data also demonstrate that complete regression and prevention of LVH in HD patients is possible.     

Ionized serum calcium levels during acute renal failure: intermittent hemodialysis vs. Continuous hemodiafiltration

BACKGROUND: Achieving "adequacy of dialysis" includes the maintenance of normal serum ionized calcium concentrations and is an important therapeutic goal in the treatment of acute renal failure (ARF). It is unknown whether this goal is best achieved with intermittent or continuous renal replacement therapy. METHODS: We compared the effects of continuous veno-venous hemodiafiltration (CVVHDF) and intermittent hemodialysis (IHD) on serum ionized calcium concentrations using daily morning blood tests in 88 consecutive intensive care patients of which half were treated with IHD and half with CRRT. RESULTS: Mean patient age was 54 +/- 14 years for IHD and 60 +/- 14 years for CVVHDF (NS). However, patients who received CVVHDF were significantly more critically ill (mean APACHE II scores: 24.4 +/- 5.1 for IHD vs. 29.2 +/- 5.7 for CVVHDF, p < 0.003). Before treatment, the mean ionized calcium concentration was 1.177 +/- 0.03 mmol/l for IHD and 1.172 +/- 0.04 mmol/l for CVVHDF (NS), with abnormal values in 51.6% of IHD patients and in 68% of CVVHDF patients (NS). During treatment, hypocalcemia was significantly more common among CVVHDF patients (24.5% vs. 14.9%; p < 0.011) while hypercalcemia was more frequent during IHD (36.1% vs. 25.6%; p < 0.019). CONCLUSIONS: Abnormal serum ionized calcium concentrations are frequent in ARF patients before and during renal replacement. Once dialytic therapy is applied, CVVHDF is more likely to lower serum calcium concentrations, while IHD is more likely to induce hypercalcemia. Appreciation of these different biochemical effects may assist clinicians in adjusting dialytic therapy in selected patients.     

Smoking is associated with alterations of blood thiol-group related antioxidants in patients on hemodialysis

Cardiovascular disease is the major complication and cause of mortality in the dialysis population, accounting for about 40% of deaths. Oxidative stress has been strongly implicated in the pathogenesis of these events. As patients in end-stage renal disease (ESRD) are in a state of elevated free radical activity, the aim of the present study was to investigate the negative impact of smoking in 45 male hemodialysis (HD) patients. These patients, who were 40-85 years of age (mean age 60.9 +/- 13.3 years), had been on hemodialysis for at least 12 months before participating in this study. Fasting blood sampling for serum lipid, albumin, urate, lipid peroxides total blood glutathione (tGSH), non-GSH free sulfhydryl compounds (non-GSH fSH), plasma glutathione peroxidase (pGSHPx), erythrocytes glutathione peroxidase (rGSHPx), plasma glutathione S-transferase (pGST) and erythrocytes glutathione S-transferase (rGST) were determined. Our study showed that the plasma malonyldialdehyde (MDA) concentration was significantly higher in HD patients who smoked than in those who were non- smokers (1.99 +/- 0.53 vs. 1.55 +/- 0.46 nmol/ml, p = 0.008). No association was found between levels of MDA in smokers and BMI, serum cholesterol and triglycerides and smoking index. We also found that the circulating plasma levels of tGSH and non-GSH fSH was lower in the HD patients who smoked (tGSH 164.9 +/- 41.5 vs. 203.4 +/- 45.3 microg/ml; fSH 271.1 +/- 55.8 vs. 308.8 +/- 46.7 microg/ml; p < 0.05 and p < 0.001, respectively). There were no significant differences in the plasma levels of uric acid, pGSHPx, rGSHPx, pGST, rGST, albumin, and age between the 2 groups. Partial correlation analysis of the plasma levels of the measured antioxidants and the smoking index revealed a negative correlation between the plasma levels of tGSH and smoking index (r = -0.62, p < 0.003). Similarly, the plasma levels of tGSH was found negatively correlated with the levels of plasma MDA (r = -0.32, p < 0.05) of the HD patients. In conclusion, our data suggest that cigarette smoking has a negative impact on plasma-circulating products of lipid peroxidation in HD patients. The lower blood levels of the tGSH and non-GSH fSH in HD patients who smoked suggests that these patients may be more susceptible to oxidative damage caused by smoking.     

Blood pressure and ejection fraction changes due to ultrafiltration in hemodialysis

BACKGROUND: Nocturnal hypertension (NH) is an unsolved problem in hemodialysis (HD) patients. The effect of ultrafiltration (UF) on NH and myocardial performance has not been systematically investigated in HD patients. METHODS: Seventeen reverse-dipper (RD) HD patients were subjected to intensified UF. Before and after UF, echo-cardiographic and blood pressure (BP) measurements were taken. RESULTS: Excluding daytime diastolic BP, all BP parameters (mmHg), namely daytime systolic BP (138.1 +/- 15.1; 131.1 +/- 12.5), night-time systolic BP (150.4 +/- 17.6; 125.3 +/- 16.5), night-time diastolic BP (87.3 +/- 10.3; 76.5 +/- 11.6), daytime pulse pressure (56.1 +/- 7.6; 50.5 +/- 5), night-time pulse pressure (63.3 +/- 9.4; 48.7 +/- 7), significantly decreased (p < 0.001 for all comparisons). Thirteen patients converted to non-dipper and two patients converted to dippers, whereas two patients remained on RD. Unit for measurement of diameters was mm. Ejection fractions (EF) increased (51.23 +/- 9.01; 64.05 +/- 7.23, p < 0.001), left atrial diameters (LAD) decreased (35 +/- 8.29; 32.05 +/- 7.12, p < 0.001), the vena cava inferior collapse index increased (VCICI) [24.82 +/- 8.20 (%); 51.76 +/- 9.65 (%), p < 0.001], left ventricular end-systolic (LVES) and diastolic diameters (LVED) decreased (3.19 +/- 0.60; 2.77 +/- 0.51, p < 0.001; 4.39 +/- 0.65; 4.18 +/- 0.56, p = 0.002, respectively). Percentage reduction in night-time diastolic BP correlated with the percentage reduction in LAD (p = 0.038). Percentage reduction in night-time pulse pressure correlated with the percentage increase in EF (p < 0.013). Similarly, percentage reductions in night-time systolic BP, night-time diastolic BP and night-time mean BP correlated with the percentage reduction in LVESD (p = 0.014, p < 0.001 and p = 0.001, respectively). CONCLUSIONS: NH in HD patients is a volume dependent phenomenon. Improved night-time BP parameters have a more profound effect on myocardial function than daytime BP parameters.     

Successful radiofrequency ablation determines atrio-ventricular remodelling and improves systo-diastolic function at tissue Doppler-imaging.

BACKGROUND: Clinical, echocardiographic results and determinants of atrial fibrillation (AF) recurrence following AF ablation during mitral valve surgery (AFAMVS) were evaluated. METHODS: Fifty-two patients undergoing radiofrequency AFAMVS between January 2003 and December 2005, underwent serial echocardiographies with tissue Doppler imaging to assess atrio-ventricular function. Recurrence of AF, hospital readmission, episodes of congestive heart failure (CHF) were recorded. Predictors for AF-recurrence were evaluated. RESULTS: At a 29.5+/-8.6 months of follow-up (100% complete), 78.8% patients were in sinus rhythm (SR). Freedom from AF-recurrence was 64.6+/-0.76%, from hospital readmission 88.9+/-0.47%, from CHF 91.6+/-0.63%. SR-patients demonstrated better freedom from hospital readmission (97.4 vs 60.6%; p=0.0003) and from CHF (100 vs 72.7%; p=0.008) during follow-up. At follow-up SR-patients demonstrated left atrial (preoperative 5.8+/-0.8 cm vs follow-up 5.1+/-0.9; p=0.013) and ventricular reverse remodelling (preoperative LVDd 5.7+/-1.1cm vs follow-up 5.2+/-1.1; p=0.048 - preoperative LVDs 4.0+/-1.4 vs follow-up 3.6+/-1.1; p=0.036). E/A ratio was normal in 73.1% (92.7% of SR-patients). TDI at the level of the left lateral annulus showed an improved left ventricular systole (Sm), and diastole (Em, E/Em) of SR-patients, compared with AF-patients (Sm 9.40+/-1.74 vs 7.72+/-1.5, p=0.0001; Em: 10.45+/-1.98 vs 7.68+/-0.72, p=0.001; E/Em: 0.07+/-0.02 vs 0.10+/-0.04, p=0.0001). Large preoperative atrial diameter (OR=5.81; p=0.002), preoperative NYHA-IV (OR=3.55; p=0.001), high diuretics at discharge (OR=1.27; p=0.03), tricuspid insufficiency at follow-up (OR=2.31; p=0.02) were independent predictors of AF-recurrence. CONCLUSIONS: Radiofrequency AFAMVS achieves 78.8% of SR recovery. Maintenance of SR improves clinic, haemodynamic and echocardiographic endpoints. Pre- and post-operative cardiac failure is the main determinant of AF-recurrence.     

Hemodialysis with low-temperature dialysate: a long-term experience

The effect of cool dialysate in hemodialysis (HD)-induced symptoms was studied in a group of 8 patients, neither diabetic nor anephric, with a high incidence of HD-induced hypotension (20-90%). Patients were studied during two consecutive periods of 6 months, the first one with dialysate at 37 degrees C (598 sessions) and the second one at 35 degrees C (599 sessions). Dialysis at low temperature was associated with a decrease in symptomatic hypotension (SH) (47.4 vs. 33.9%, p less than 0.001), a greater loss of weight during HD (1.52 +/- 0.03 vs. 1.71 +/- 0.03 kg, p less than 0.001) and stabilization of predialysis systolic blood pressure (SBP) at a lower level (144 +/- 0.69 vs. 139 +/- 0.98 mm Hg, p less than 0.001). At 37 degrees C, SH was associated with a higher ultrafiltration (1.71 +/- 0.05 vs. 1.32 +/- 0.05 kg, p less than 0.001). There was an improvement of symptoms both taken as a whole (55.6 vs. 45.8%, p less than 0.01) or one by one, cramps were the only exception as they increased at 35 degrees C (2.7 vs. 10.9%, p less than 0.001) being related with a greater weight loss at both temperatures (1.47 +/- 0.04 vs. 2.04 +/- 0.25 kg at 37 degrees C, p less than 0.001; 1.76 +/- 0.03 kg vs. 2.23 = 0.10 kg at 35 degrees C, p less than 0.001). In spite of the increase in the frequency of cramps, 7 out of 8 patients experienced some amelioration of dialysis symptoms (range between 7 and 21.4%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Atrial fibrillation and plasma troponin I elevation after cardiac surgery: relation to inflammation-associated parameters

BACKGROUND: Recent studies have demonstrated correlation between inflammation to plasma troponin (cTnI) levels elevation and atrial fibrillation (AF) in noncardiac surgery settings. The goal of this prospective study was to examine the relation between inflammation associated parameters (IAPs) to post cardiac surgery cTnI elevation and AF. METHODS: A single post CABG cTnI measurement was assessed in 156 consecutive patients. Clinical, operative and postoperative data, IAPs (hypophosphatemia, preoperative statin treatment, immediate postoperative fever, and prolonged mechanical ventilation) and in-hospital AF episodes were prospectively recorded. RESULTS: Mean cTnI level was 14.4 +/- 12.4 ng/mL. In the two in-hospital deaths (1.2%) cTnI concentration was less than 12 ng/mL. Cardiac troponin-I levels were significantly higher in patients not preoperatively treated with statins (21.6 +/- 4.1 vs. 13.3 +/- 0.9, p = 0.05), in patients who needed intraoperative cardioversion (16.7 +/- 2.2 vs. 12.2 +/- 0.9, p = 0.07), in patients with postoperative hypophosphatemia (16.9 +/- 10.0 vs. 11.1 +/- 13.7, p = 0.04), postoperative fever (18.6 +/- 3.0 vs. 13.7 +/- 1.0, p = 0.07) and postoperative respiratory complications (23.9 +/- 4.3 vs. 13.5 +/- 1.0, p = 0.04). Step-wise logistic regression analysis revealed the following parameters as independently associated with elevated cTnI levels: preoperative statin treatment (CI 95%-15.9; -1.7, p = 0.02), intraoperative ventricular arrhythmia (CI 95%-0.7; 13.8, p = 0.08), hypophosphatemia (CI 95% 0.9; 8.6, p = 0.02), postoperative fever (CI 95% 0.9; 11.0, p = 0.02), and postoperative respiratory complications (CI 95% 0.1; 0.5, p = 0.01). Of the 156 patients, 50 (32.1%) had postoperative AF. The first episode of AF occurred between postoperative day 1 and 6 (mean-day 2). Mean duration of AF was 21.8 +/- 8.1 hours. Postoperative AF was significantly associated with age above 75 (50% vs. 29.4%, p = 0.01), hypertension (37% vs. 18%, p = 0.02), preoperative calcium channel blockers treatment (44% vs. 26%, p = 0.02), furosemide treatment (58% vs. 30%, p = 0.05), and preoperative left atrial diameter above 40 mm (56% vs. 29%, p = 0.01). Postoperatively, AF was significantly associated with postoperative renal failure (70% vs. 29%, p = 0.01), respiratory complications (61% vs. 29%, p = 0.02), and prolonged hospital stay (OR 1.1; CI 1.0-1.3; p < 0.05). No association was found between troponin levels and postoperative AF. Multivariable analysis found only left atrial enlargement and prolonged hospital stay independently associated with AF. CONCLUSIONS: A significant correlation between clinical IAPs and cTnI plasma level elevation was found after cardiac surgery. There was no correlation between these parameters and postoperative AF, and there was no correlation between postoperative plasma cTnI levels and the occurrence of AF. Preoperative treatment with statins may be beneficial in reducing postoperative inflammatory response but further study has to be carried out.     

Oxidative stress, sister chromatid exchanges and apoptosis in the pathogenesis of lymphocytopenia in ESRD patients

BACKGROUND: In end-stage renal disease (ESRD) patients on hemodialysis (HD) there may be a link between oxidative stress, genomic damage and the tendency of peripheral lymphocytes to die by apoptosis. Our aim was to verify this hypothesis, and to ascertain whether the link, if present, could explain lymphopenia in uremic patients. METHODS: The series investigated comprised 55 participants: 30 HD patients on regular maintenance acetate-free bio-filtration (AFB) and 25 age-matched healthy volunteers. One blood sample was drawn from the cubital vein of each participant. In HD patients, samples were drawn 3 times: predialytic, postdialytic and interdialytic (24 hours after the end of the session). Thiobarbituric acid reactants (TBARs), sister chromatid exchange (SCE) rate, high frequency cells (HFCs), total circulating lymphocytes and the percentage of circulating apoptotic lymphocytes were assayed in all samples. A statistical analysis of the findings was made using multiple and linear regression. RESULTS: In AFB patients, TBAR levels appeared higher than in controls, even at baseline (2.15 +/- 0.5 micromol/L vs. 1.20 +/- 0.4 micromol/L; p < 0.05). The highest peak occurred at the end of the session (3.2 +/- 0.4 micromol/L; p < 0.05 vs. basal), and a prompt return to basal values was observed 24 hours later (2.2 +/- 0.6 micromol/L, p < 0.5 vs. basal). In AFB patients, the per-centages of HFCs (8.63% vs. 3%; p < 0.05), SCE (6 +/- 0.6 vs. 4.65 +/- 2.18; p < 0.04) and apoptotic lymphocytes (3-fold) were greater than in controls, even at baseline, whereas the values for total lymphocytes were lower (1,140 +/- 652 vs. 1,590 +/- 822). After an AFB session the differences between patients and control values appeared greater (HFCs, 16.81%, p < 0.04 vs. basal; SCE, 7.02 +/- 1.2, p < 0.03; apoptotic lymphocytes 3.5-fold greater than control values). Twenty-four hours later, a further increase was observed in the expression of genomic damage (HFCs, 50%, p < 0.05 vs. basal; SCE, 9.82 +/- 2.1, p < 0.03) and the percentage of apoptotic lymphocytes (4.7-fold greater than control values), while the lowest peak occurred for total circulating lymphocyte count (997 +/- 854, p < 0.04). At linear regression, a strong positive correlation was found between HFCs and TBARs at the beginning and at the end of the AFB session(r = 0.7, p < 0.03). With multiple regression analysis, a strong positive correlation was found between TBAR levels at the end of AFB session, HFC rate and apoptotic lymphocytes at 24 hours, with the last as the dependent variable (multiple r = 0.8, TBARs, beta = 0.51, p < 0.04; HFCs, beta = 0.43, p < 0.03). DISCUSSION AND CONCLUSIONS: An AFB session has an immediate impact, causing an increase in TBAR levels, genomic da-mage and lymphocytic apoptosis. Twenty-four hours after the session there was a further expression of genomic damage, and an increase in apoptosis, while the peak for lymphocytes dropped sharply. Our findings indicate that lymphopenia affecting end-stage renal disease (ESRD) patients may be strictly related to genomic damage exerted, at least in part, by TBARs, and to a dysregulation in programmed cell death.     

Infective endocarditis in maintenance hemodialysis patients: fifteen years' experience in one medical center

BACKGROUND: Infective endocarditis (IE) is a serious infectious condition, with high morbidity and mortality in hemodialysis (HD) patients. This study was undertaken to determine the IE risk factors in maintenance HD patients, and the mortality risk factors. METHODS: We retrospectively reviewed all IE cases of maintenance HD patients at our center over the past 15 yrs (the study group). Regular HD patients without IE in the same period were used as the control group. The basic data of the two groups were analyzed to determine IE risk factors in HD patients. The in-hospital parameters of survival and mortality in the study group patients were used for mortality risk factors analysis. RESULTS: There were 18 definite, and two possible, IE diagnoses in the study group and no cases in the 268 controls. There was no significant difference in age, sex, diabetes, hypertension, underlying malignancy, previous cerebral vascular accident (CVA) history, and calcium multiplied by phosphate product. There was a significant difference between the two groups (study group vs. controls) in pacemaker implant history (15 vs. 1.1%, p<0.01), previous heart surgery history (15 vs. 0.4%, p<0.01), congestive heart failure (CHF) (50 vs. 10.4%, p<0.05), duration on maintenance HD (12.9+/-19.1 vs. 57.9+/-42.3 months, p<0.001), serum albumin at the time of admission (2.91+/-0.40 vs. 3.96+/-0.52 g/dL, p<0.001). There were more patients dialyzed via non-cuffed dual-lumen catheters in the study group (55 vs. 0%, p<0.001), and fewer patients dialyzed via arteriovenous fistula (AVF) (25 vs. 87.7%, p<0.001). The mortality in HD patients with IE was high (60%), especially in patients with methicillin-resistant Staphylococcus aureus (MRSA) endocarditis (100%). The most common pathogen was S. aureus (n=12). MRSA was more common than methicillin-susceptible S. aureus (MSSA) (67 vs. 33%). Univariant analysis of in-hospital clinical parameters for mortality revealed no significant difference in age, diabetes, dual-lumen catheter implantation, serum albumin, time to diagnosis, and time to antibiotic use. Borderline statistical significance was noted in serum C-reactive protein (CRP) (p=0.051), and blood glucose level (p=0.056). There were more IE cases due to MRSA in the mortality group than in the survival group (8 vs. 0 cases, p=0.013), but fewer cases due to MSSA (0 vs. 4 cases, p=0.050). CONCLUSIONS: IE should be considered in HD patients with the following risk factors, which include previous heart surgery or pacemaker implantation, shorter HD duration, and especially for patients dialyzed via dual-lumen catheters. The in-hospital clinical parameters including CRP and blood sugar level can offer information concerning prognosis. Since MRSA has increased in recent years and is associated with high mortality, strategies for prevention and treatment require development.     

Heart rate variability, left ventricular functions, and cardiac autonomic neuropathy in patients undergoing chronic hemodialysis

OBJECTIVE: Autonomic neuropathy and impairment of left ventricular functions (LVF) have been frequently encountered in chronic renal failure (CRF). The aim of the present study was to evaluate the relationship of cardiac autonomic modulation impairments, as assessed by means of heart rate variability (HRV), with clinical characteristics, and left ventricular function in the patients with CRF undergoing hemodialysis (HD). METHODS: Twenty control subjects (Group I) and 22 comparable by age and gender patients with CRF undergoing hemodialysis (Group II) were enrolled in the study. After routine clinical and biochemical evaluations, electrocardiography, and 2 Dimensional, M Mode echocardiography were performed in all participants. Frequency domain HRV analysis was studied by using Kardiosis System. The powers (P1 and P2) and the central frequencies (F1 and F2) of low and of high frequency spectral bands were recorded. RESULTS: End systolic (ESV) and end diastolic volumes (EDV) were significantly higher in Group II (59.3 +/- 21.1mL vs. 34.0 +/- 14.3 mL and 131.5 +/- 37.3 mL vs. 96.9 +/- 18.9 mL, p < 0.01, p < 0.05, respectively) when compared to those of Group I. Ejection fraction (EF) and fractional shortening (FS) were significantly lower in Group II than in control subjects (52.3 +/- 2.4% vs. 63.7 +/- 10.1% and 0.29 +/- 0.01 vs. 0.34 +/- 0.07, p < 0.001, p < 0.05, respectively). P and P2 were decreased in Group II than in Group I (136.2 +/- 173.9 m s2 vs. 911.0 +/- 685.5 and 96.5 +/- 149.6 vs. 499.7 +/- 679.5, p < 0.001, p < 0.01, respectively). Significant correlations were found between high frequency spectral power and dialysis duration (DD), ESV, EDV, EF, FS (r = 0.52 p < 0.01, r = 0.68 p < 0.001, r = 0.65 p < 0.002, r = 0.66 p < 0.02, and r = 0.69 p < 0.01). CONCLUSION: As a result, the dependence of cardiac autonomic neuropathy on the disease duration and degree of left ventricular function impairment was shown in the patients undergoing chronic hemodialysis.     

Factors that affect oxygen affinity of hemoglobin in chronic hemodialysis patients

To investigate various factors that possibly affect oxygen affinity of hemoglobin (Hb-O2 affinity) in chronic hemodialysis (HD) patients, we determined P50 at standard condition (P50std), 2,3-diphosphoglycerate (2,3-DPG) content in red blood cells, serum inorganic phosphorus (S-Pi), Hb, and arterial blood gas analysis in 55 HD patients. P50std in HD patients was higher than that in normal controls (26.6 +/- 1.6 vs. 25.4 +/- 1.4 mm Hg; p less than 0.001). We could find neither an effect of alkalizating agents for HD (acetate vs. bicarbonate) nor an effect of the underlying disease (diabetics vs. nondiabetics) on Hb-O2 affinity. There were significant positive correlations between P50std and the duration of HD therapy (r = 0.598; p less than 0.001) and between P50std and SPi (r = 0.476; p less than 0.001), contrasting with the absence of correlation between P50std and Hb. Forward stepwise multiple-regression analysis demonstrated that the duration of HD therapy played the most important roles in determining P50std, followed by SPi and PO2. These data suggest that the major factor influencing Hb-Os affinity in chronic HD therapy is the duration of the therapy and that the minor factors are SPi and PO2.     

Cardiac transplantation for cardiomyopathy and ischemic heart disease: differences in outcome up to 10 years.

BACKGROUND: Ischemic heart disease (IHD) and cardiomyopathy (CM) are the most common indications for heart transplantation. The aim of this study was to investigate the difference in clinical outcome between these two groups. METHODS: At our institution between 1987 and 1998 transplantation was performed in 133 patients with IHD and 87 with CM. Follow-up was complete for all patients (mean 87 months). RESULTS: Mean age at time of surgery was 51 +/- 5 years for IHD versus 39 +/- 9 years for CM recipients (p = 0.02). There was no difference in donor age, donor gender, or pre-operative hemodynamics between the two groups. The operative mortality was 11.2% in IHD recipients and 10.6% in CM recipients (p = 0.9). No differences were observed in intra-cardiac pressures or incidence of renal dysfunction, infection, or malignancy between the two groups. The incidence of peripheral vascular incidents was significantly higher for IHD recipients (13% vs 3%, p = 0.02). At 10 years, the incidence of coronary artery disease was 35% and 9%, respectively (p = 0.02). Mean NYHA status was 2.0 +/- 0.3 and 1.1 +/- 0.2 for IHD and CM recipients, respectively (p = 0.013). The actuarial survival at 1, 5, and 10 years was 77%, 62%, and 39% for IHD recipients compared with 85%, 82%, and 80% for CM recipients (p = 0.7, p < 0.0001 and p < 0.0001, respectively). CONCLUSION: After heart transplantation, medium- and long-term outcome is significantly better for CM than IHD recipients. In view of limited donor availability, it is appropriate to explore more vigorously alternative treatments for patients with severe ischemic left ventricular dysfunction.     

Shoulder ultrasound in dialysis related amyloidosis.

Ultrasonographic changes around the shoulder joint were compared in ten symptomatic patients with dialysis related amyloid (DRA) and seventeen patients without symptoms. All patients had been on long-term (greater than 7 years) hemodialysis (HD). Three control groups were used: 8 predialysis patients, 10 continuous ambulatory peritoneal dialysis (CAPD) and 9 HD patients who had been on dialysis for less than two years. Dry bodyweight, sex, handedness, length of hemodialysis and fistula side were not significantly different between the study groups. Proven amyloid patients were significantly older than other groups (p less than 0.001). Parameters assessed included cross-sectional area of long head of biceps tendon (LHB), diameter of supraspinatus tendon (SS), and general features (bursae, deposits) around the joint. Results demonstrated significant differences in all parameters in patients with symptomatic amyloid compared with other long-term patients: [SS: 7.4 mm +/- 0.7, mean +/- SEM, vs 5.1 +/- 0.2 (right, R), p = 0.001; 6.7 +/- 0.7 vs 4.9 +/- 0.2 (left, L), p = 0.01. LHB: 140.0 mm2 +/- 11.1 vs 79.6 +/- 5.1 (R), p less than 0.001; 114.5 +/- 10.5 vs 80.8 +/- 5.4 (L), p = 0.004. Bursae: 5 vs 1 (patients), p = 0.006]. Compared with controls changes in the amyloid group were less marked though in most cases still significant. There was no significant difference between control groups nor between controls and asymptomatic long-term HD patients in any parameter. We conclude that shoulder ultrasound may have a role in identifying patients with dialysis related amyloid. Serial measurements may also help to elucidate the pathogenesis of the tendon changes.     

Atrial fibrillation after cardiac surgery: a major morbid event?

OBJECTIVE: The purpose of the study was to investigate the incidence, predictors, morbidity, and mortality associated with postoperative atrial fibrillation (AF) and its impact on intensive care unit (ICU) and postoperative hospital stay in patients undergoing cardiac surgery in the Department of Veterans Affairs (VA). SUMMARY BACKGROUND DATA: Postoperative AF after open cardiac surgery is rather common. The etiology of this arrhythmia and factors responsible for its genesis are unclear, and its impact on postoperative surgical outcomes remains controversial. The purpose of this special substudy was to elucidate the incidence of postoperative AF and the factors associated with its development, as well as the impact of AF on surgical outcome. METHODS: The study population consisted of 3855 patients who underwent open cardiac surgery between September 1993 and December 1996 at 14 VA Medical Centers. Three hundred twenty-nine additional patients were excluded because of lack of complete data or presence of AF before surgery, and 3794 (98.4%) were male with a mean age of 63.7+/-9.6 years. Operations included coronary artery bypass grafting (CABG) (3126, 81%), CABG + AVR (aortic valve replacement) (228, 5.9%), CABG + MVR (mitral valve replacement) (35, 0.9%), AVR (231, 6%), MVR (41, 1.06%), CABG + others (95, 2.46%), and others (99, 2.5%). The incidence of postoperative AF was 29.6%. Multivariate logistic regression analysis of factors found significant on univariate analysis showed the following predictors of postoperative AF: preoperative patient risk predictors: advancing age (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.48-1.75, p < 0.001), chronic obstructive pulmonary disease (OR 1.37, 95% CI 1.12-1.66, p < 0.001), use of digoxin within 2 weeks before surgery (OR 1.37, 95% CI 1.10-1.70, p < 0.003), low resting pulse rate <80 (OR 1.26, 95% CI 1.06-1.51, p < 0.009), high resting systolic blood pressure >120 (OR 1.19, 95% CI 1.02-1.40, p < 0.026), intraoperative process of care predictors: cardiac venting via right superior pulmonary vein (OR 1.42, 95% CI 1.21-1.67, p < 0.0001), mitral valve repair (OR 2.86, 95% CI 1.72-4.73, p < 0.0001) and replacement (OR 2.33, 95% CI 1.55-3.55, p < 0.0001), no use of topical ice slush (OR 1.29, 95% CI 1.10-1.49, p < 0.0009), and use of inotropic agents for greater than 30 minutes after termination of cardiopulmonary bypass (OR 1.36, 95% CI 1.16-1.59, p < 0.0001). Postoperative median ICU stay (3.6 days AF vs. 2 days no AF, p < 0.001) and hospital stay (10 days AF vs. 7 days no AF, p < 0.001) were higher in AF. Morbid events, hospital mortality, and 6-month mortality were significantly higher in AF (p < 0.001): ICU readmission 13% AF vs. 3.9% no AF, perioperative myocardial infarction 7.41 % AF vs. 3.36% no AF, persistent congestive heart failure 4.57% AF vs. 1.4% no AF, reintubation 10.59% AF vs. 2.47% no AF, stroke 5.26% AF vs. 2.44% no AF, hospital mortality 5.95% AF vs. 2.95% no AF, 6-month mortality 9.36% AF vs. 4.17% no AF. CONCLUSIONS: Atrial fibrillation after cardiac surgery occurs in approximately one third of patients and is associated with an increase in adverse events in all measurable outcomes of care and increases the use of hospital resources and, therefore, the cost of care. Strategies to reduce the incidence of AF after cardiac surgery should favorably affect surgical outcomes and reduce utilization of resources and thus lower cost of care.