[Impact of left ventricular patterns and diastolic dysfunction on hemodialysis patients]. / Pattern cardiaci geometrici e disfunzione diastolica nel paziente uremico: quale l'impatto sul trattamento dialitico?

BACKGROUND: Left ventricular hypertrophy is the main manifestation of uraemic cardiomyopathy and predicts both cardiovascular events and death independently of conventional risk factors. Diastolic dysfunction is often associated with left ventricular hypertrophy, and accounts for up to 30% of heart failure. The aim of this study was to estimate the impact and the prevalence of left ventricular hypertrophy, its geometric models and diastolic dysfunction on haemodialysis patients, as well as the relationship with cardiac troponin, a specific marker for myocardial damage. METHODS: We enrolled in the study 31 patients (26 on haemodialysis, 5 on peritoneal dialysis) and 31 normal healthy subjects as the control group. Echocardiographic measurements were carried out according to the recommendations of the American Society of Echocardiography. Left ventricular mass was calculated according to the Devereux formula and indexed to height 2.7 We carried out Doppler echocardiography to study the diastolic function by measurements of isovolumic relaxation period (IVRT), E-wave deceleration time (DTE) and E/A ratio. We measured cardiac troponin using a third generation electrochemiluminescence immunoassay. We did the statistical analysis with the t test for comparison among groups, and we established correlations using the Pearson and Spearman correlation test. We considered values of p<0.05 to be statistically significant. RESULTS: Eccentric hypertrophy was the most frequent pattern (n=17; 55%), followed by normal cardiac geometry (n=7; 23%) and concentric hypertrophy (n=5; 16%). Only a minority of patients (n=2; 6%) showed concentric remodelling. Systolic dysfunction was present in 3 patients (EF<50%). Diastolic dysfunction was present in 24 out of 31 HD patients, that had abnormal relaxation pattern, characterised by prolonged IVRT, prolonged DTE and E/A ratio <1. Only one patient had restrictive filling pattern with reduced DTE and E/A ratio >2. Fourteen patients (45%) had E/A ratio < or =0.5, 10 patients (32%) had E/A ratio >0.5<1 and 7 patients (13%) had E/A ratio > or =1. DTE was prolonged in 14 patients (45%) and IVRT was prolonged in 6 patients (19%). The patients with E/A ratio < or =0.5 (n=14; 45%) suffered major hypotensive episodes during dialytic sessions compared to patients with E/A ratio >0.5, we found this difference to be statistically significant (p < 0.01). We observed the E/A ratio to be negatively correlated with age (r = -0.41; p=0.02) whereas DTE was positively correlated with posterior wall thickness (r =0.36; p= 0.05) and interventricular septum thickness (r =0.45; p=0.01). Cardiac troponin was positively correlated with age (r =0.50; p=0.00), left ventricular mass (r =0.41; p=0.02), posterior wall thickness (r =0.41; p=0.02) and interventricular septum thickness (r =0.39; p=0.03) but not with diastolic dysfunction parameters. Serum cardiac troponin was elevated (> or =0.10 micro g/L) in 12 patients (38.7%) and was associated with eccentric hypertrophy in all the cases. We detected no significant differences among groups with normal left ventricular geometry and left ventricular hypertrophy in the duration of the dialytic treatment, but we noted a statistically significant difference in relationship to age (p=0.03). CONCLUSIONS: Left ventricular hypertrophy is associated with diastolic dysfunction, both cause of hypotensive episodes during dialytic treatments and heart failure in patients with normal systolic function. The non invasive assessment of left ventricular diastolic function would represent an important advancement in the diagnosis and prevention of heart failure in haemodialysis patients.

[The measurement of vascular access recirculation and intra-access pressure in arteriovenous fistula monitoring in hemodialysis]. / La misura del ricircolo e delle pressioni statiche dell'accesso vascolare nel monitoraggio delle fistole artero-venose in emodialisi.

BACKGROUND: The main objective of monitoring vascular access flow in haemodialysis is maintenance of adequate access blood flow (Qac ) to prevent underdialysis and detection of haemodynamically significant stenosis prior to thrombosis. METHODS: Recirculation and intra-access pressure were measured to monitor arteriovenous fistulae in a group of haemodialysed patients, for a period of six months. Vascular access blood flow measurements were taken at the first (t0), second (t1) and sixth month (t2) by recirculation measurements using the thermodilution technique (BTM) consistent with Krivitsky's theory. Intra-access pressure measurements were made using the simplified Besarab's method. RESULTS: No statistically significant differences were noted in recirculation, vascular access blood flow, cardiac output and intra-access measurements during the three periods of the study. Vascular access blood flow was significantly and positively correlated with the arterial blood pressure measured at the same time, but not with the intra-access and venous pressures. Data indicate that mean Qac values = 300 mL/m. and induced recirculation values (Rp) = 45 and = 50 are correlated with angiographic findings of vascular access dysfunction. We observed that patients with mean Qac values between 300 and 650 mL/m had negative angiograms. CONCLUSIONS: We conclude that calculation of access flow by the double recirculation technique is a better and earlier predictor of access dysfunction whereas intra-access pressure measurements are not as useful for this purpose.

Efficacy and safety of three 7-day Helicobacter pylori eradication regimens containing ranitidine bismuth citrate.

BACKGROUND: This multicentre, randomized study was designed to assess the clinical efficacy, safety and tolerability of three novel 7-day triple therapies containing ranitidine bismuth citrate (RBC) and two antibiotics. METHODS: We studied patients with non-ulcer dyspepsia and gastritis who were randomly assigned to one of three treatment regimens given for 7 days in a b.d. dosing schedule: RBC 400 mg plus clarithromycin 250 mg and tinidazole 500 mg (RBCCT): RBC 400 mg plus clarithromycin 500 mg and amoxycillin 1 g (RBCCA); RBC 400 mg plus tinidazole 500 mg and amoxycillin 1 g (RBCTA). H. pylori status was determined by CLO-test, histology and 13C-urea breath test. A repeat breath test was performed at least 28 days after completion of therapy to assess eradication. RESULTS: One hundred and fifty-seven patients were eligible for intention-to-treat analysis (ITT) and 140 patients completed the study and returned for assessment of eradication. Intention-to-treat cure rates were 78% with RBCCT, 71% with RBCCA and 61% with RBCTA. An all-patients-treated analysis (APT), performed on evaluable patients, demonstrated eradication rates of 85% with RBCCT, 81% with RBCCA and 70% with RBCTA. No statistically significant difference was found between treatment groups. Twenty-four patients experienced side-effects, but in only seven cases was treatment discontinued due to adverse events. CONCLUSIONS: A 7-day course of RBC, clarithromycin and either tinidazole or amoxycillin provides a good rate of H. pylori eradication. Three novel RBC-based triple therapies proved to be safe and well tolerated, with discontinuations due to side-effects occurring in less than 5% of cases.