Simonetta Genovesi

Atrial Fibrillation and Morbidity and Mortality in a Cohort of Long-term Hemodialysis Patients

BACKGROUND Atrial fibrillation is associated with increased mortality and hospitalization in the general population. Data about mortality, morbidity, and hospitalization in hemodialysis patients with atrial fibrillation are limited. SETTING & PARTICIPANTS All patients (n = 476) in 5 dialysis centers in Lombardia, Italy, as of June 2003 were enrolled and followed up until June 2006 (median age, 69 years; median hemodialysis duration, 45.2 months; and median follow-up, 36 months). 127 patients had atrial fibrillation at enrollment. PREDICTORS & OUTCOME A Cox model was used to relate: (1) atrial fibrillation, age, hemodialysis therapy duration, and comorbid conditions to all-cause and cardiovascular mortality; (2) angiotensin-converting enzyme (ACE)-inhibitor treatment and comorbid conditions to new onset of atrial fibrillation; and (3) atrial fibrillation and comorbid conditions on hospitalization. RESULTS There were 167 deaths (39.5% from cardiovascular disease). In multivariable models, atrial fibrillation was independently associated with increased mortality (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.18 to 2.31). This was more notable for cardiovascular (HR, 2.15; 95% CI, 1.27 to 3.64) than noncardiovascular mortality (HR, 1.39; 95% CI, 0.89 to 2.15). New-onset atrial fibrillation occurred in 35 of 349 individuals (4.1 events/100 person-years); the risk of incident atrial fibrillation was lower in those using ACE-inhibitor therapy (HR, 0.29; 95% CI, 0.10 to 0.82) and higher in those with left ventricular hypertrophy (HR, 2.55; 95% CI, 1.04 to 6.26). There were 539 hospitalizations during 3 years, with 114 hospitalizations in 162 patients with atrial fibrillation and 155 hospitalizations in 314 patients without atrial fibrillation (HR, 1.54; 95% CI, 1.18 to 2.01). Rates of stroke did not significantly differ by atrial fibrillation status (P = 0.4). LIMITATIONS Because of the observational nature of this study, results for treatment need confirmation in future trials. CONCLUSIONS Atrial fibrillation is associated with greater total and cardiovascular mortality. Patients with atrial fibrillation were hospitalized more frequently than patients without atrial fibrillation. ACE inhibitors may decrease the risk of new-onset atrial fibrillation.

Results of blood pressure screening in a population of school-aged children in the province of Milan: role of overweight.

Objectives To study the prevalence of high blood pressure (BP) in an Italian paediatric population, and to verify whether in this population elevated BP values are associated with overweight (OW). Study design Children (1206 males, 1210 females) from the lower-grade public schools (ages 6–11 years) were studied. Body weight, height and BP were measured in each child. Elevated BP was defined if resting systolic and/or diastolic BP values equalled or exceeded the 95th percentile according to gender, age and height, based on the US normative BP tables. Overweight children were identified using four different methods: (1) the classification based on the relative body weight; (2) the French references by Rolland-Cachera et al. (Am J Clin Nutr 1982; 36:178–184); (3) the International Obesity Task Force charts; and (4) the Italian charts defined by Cacciari et al. (Eur J Clin Nutr 2002; 56:171–180). Results The prevalence of high BP in our population was 4.2% and was significantly higher in females (65/1210 = 5.4%) than in males (37/1206 = 3.1%), P = 0.005. The different methods used to define OW provide different estimates of OW prevalence (from 17.0 to 38.6%). The percentage of high BP subjects was significantly higher in OW than in normal-weight children regardless of the method used for the definition of the weight class (P < 0.0001), in both genders. In addition, for each age range, absolute systolic and diastolic BP values were higher in OW as compared to normal-weight children both in males and in females (P < 0.0001). Conclusions Our study indicates the importance of performing BP screenings in the paediatric population, and to promote interventions that may reduce the prevalence of OW in children.

Sudden death and associated factors in a historical cohort of chronic haemodialysis patients

BACKGROUND In haemodialysis patients, deaths due to cardiovascular causes constitute a large proportion of total mortality and sudden cardiac deaths account for approximately 22% of all deaths. The aim of this study was to evaluate the incidence of sudden cardiac death and associated risk factors in a cohort of haemodialysis patients. METHODS AND RESULTS The 3-year cumulative incidence of death in a cohort of 476 patients on chronic haemodialysis treatment was 34.3% (SE 2.3). Sudden death had a 6.9% (SE 1.2) cumulative incidence, with 32 events representing 19.2% of all deaths, while cardiovascular not sudden death and noncardiovascular death accounted for a 3-year cumulative incidence of 7.3% (SE 1.2) and 20.1% (SE 1.9), respectively. According to Cox multivariate analysis, significant risk factors for sudden death were the presence of atrial fibrillation, diabetes mellitus, predialytic hyperkalaemia, haemodialysis mode and C-reactive protein level, which were associated with a 2.9 (CI(95%) 1.3-6.4), 3.0 (CI(95%) 1.3-7.2), 2.7 (CI(95%) 1.3-5.8), 4.5 (CI(95%) 1.3-15.5) and 3.3 (CI(95%) 1.2-8.8)-fold increase in the risk of sudden death, respectively. Sudden death was significantly more frequent during the first 24 h of the first short interdialytic interval and during the last 24 h of the long interval, i.e. immediately before and immediately after the first weekly haemodialysis session (P = 0.02). CONCLUSIONS Our data show that the incidence of sudden death in haemodialysis patients is high and that atrial fibrillation, diabetes, hyperkalaemia, haemodialysis mode and C-reactive protein play an important role in developing fatal arrhythmia. Further studies will be necessary to define which interventions could be helpful in reducing this cause of mortality.

Maternal perception of excess weight in children: a survey conducted by paediatricians in the province of Milan.

OBJECTIVE To establish whether maternal perception of a childs body weight (BW) and food intake is related to the level of maternal education. STUDY DESIGN Height and BW of 569 mother/child couples were measured, and mothers received a questionnaire regarding their perception of their own weight and their childs BW and food intake. RESULTS Twenty-nine percent of mothers and 35% of children were overweight or obese. Only 10% of the mothers underestimated their own weight, while 37% overestimated it. In contrast, 28% of mothers underestimated their childs BW, while 9% overestimated it. Higher maternal instruction level was significantly associated to a lower weight class in both mothers and children, and to a correct perception of the childs weight. Fifty-seven per cent of the mothers who perceived their child to be overweight or obese were not concerned. Forty-four per cent of the mothers with overweight or obese children believed that their child was eating correctly. CONCLUSIONS A better understanding of how mothers perceive the problem of excess weight in their children is relevant to the success of preventive interventions in childhood obesity.

Electrolyte concentration during haemodialysis and QT interval prolongation in uraemic patients.

AIMS To assess the effect of different combinations of potassium and calcium concentrations on QT interval in the dialysis bath in uraemic patients. METHODS AND RESULTS Sixteen haemodialysis (HD) patients underwent a 24 h Holter recording before and during HD sessions with six randomized combinations of electrolytes concentrations of the dialysis bath (K(+), 2 and 3 mmol/L; Ca(2+), 1.25, 1.5, and 1.75 mmol/L). The effect of different dialysis baths on QT interval was significant (P < 0.05). The longest mean QTc was observed with the lowest K(+) (2 mmol/L) and Ca(2+) concentrations (1.25 mmol/L), whereas the shortest mean QTc was observed with the highest K(+) (3 mmol/L) and Ca(2+) concentrations (1.75 mmol/L). QTc was >440 ms in 9 of 16 patients (56%) at the lowest Ca(2+) and K(+) concentrations, and in 3 of 16 patients (18%) at the highest electrolytes level. Changes in QTc during the HD sessions were inversely correlated with that in total Ca and Ca(2+) plasma concentrations (P < 0.0001). CONCLUSION Changes in ventricular repolarization duration associated with HD largely depend on the concentrations of Ca(2+) and K(+) in the dialysis bath. These findings may have important implications for the choice of the electrolytes concentration of the dialysis bath during the HD session.

Usefulness of waist circumference for the identification of childhood hypertension.

Objective To investigate the ability of BMI and waist circumference, single and combined, in identifying children who are at risk of hypertension and in influencing absolute blood pressure values. Methods The body weight, height, waist circumference and blood pressure of 4177 5–11-year-old school children [2005 (48%) girls] were collected. Elevated blood pressure was defined if either systolic or diastolic blood pressure values or both were more than the 95th percentile according to sex, age and height (US normative blood pressure tables). Overweight and obese children were defined according to International Obesity Task Force BMI cut-offs. Results The prevalence of hypertension was 4.1% and increased together with weight class: 1.4% (n = 42/3076) in normal weight, 7.1% (n = 59/827) in overweight and 25% (n = 69/274) in obese (P < 0.001). Only BMI and waist circumference showed a remarkable ability to discriminate hypertensive children (areas under receiver operating characteristic curves, 0.84 and 0.76, respectively). The multivariate analysis showed that z-scores for both BMI and waist circumference were significantly related to the risk of hypertension with odds ratios of 3.59 (95% confidence interval, 2.55, 5.06) and 1.20 (95% confidence interval, 1.04, 1.39), respectively, after adjusting for sex and age. When the weight class was included in the multivariate analysis, waist circumference retained its ability to identify hypertensive children only in the obese class (odds ratio, 1.44; 95% confidence interval, 1.21, 1.72; P < 0.01). When considering blood pressure as a continuous variable, both weight class and waist circumference showed a significant effect on systolic and diastolic blood pressure absolute values (P < 0.01). The effect of waist circumference on blood pressure values was maintained even when corrected for BMI. Conclusion High blood pressure is strongly associated with excess weight. Waist circumference improves the ability of BMI to identify hypertension in obese children. Waist circumference is related to absolute blood pressure values in all weight classes.

Warfarin use, mortality, bleeding and stroke in haemodialysis patients with atrial fibrillation

BACKGROUND Oral anticoagulation therapy (OAT) is the choice treatment for thromboembolism prevention in atrial fibrillation (AF), although data about OAT use in haemodialysis (HD) patients with AF are contradictory. METHODS The effect of OAT on the risk of mortality, stroke and bleeding was prospectively evaluated in a population of HD patients with AF. All the patients of 10 HD Italian centres alive on 31 October 2010 with documented AF episode(s) were recruited and followed-up for 2 years. OAT and antiplatelet intake, age, dialytic age, comorbidities and percentage time in the target international normalized ratio (INR) range (target therapeutic range; TTR) were considered as predictors of hazard of death, thromboembolic and bleeding events. RESULTS At recruitment, 134 patients out of 290 were taking OAT. During the follow-up, 115 patients died (4 strokes, 3 haemorrhagic and 1 thromboembolic). Antiplatelet therapy, but not OAT, was associated with increased mortality (HR 1.71, CI 1.10-2.64, P = 0.02). The estimated survival of patients always taking OAT tended to be higher than that of patients who stopped taking (68.6 versus 49.6%, P = 0.07). OAT was not correlated to a significant decreased risk of thromboembolic events (HR 0.12, CI 0.00-3.59, P = 0.20), while it was associated with an increased risk of bleeding (HR 3.96, CI 1.15-13.68, P = 0.03). Higher TTR was associated with a reduced bleeding risk (HR 0.09, CI 0.01-0.76, P = 0.03), while previous haemorrhagic events were associated with higher haemorrhagic risk (HR 2.17, CI 1.09-4.35, P = 0.03). CONCLUSIONS In our population of HD patients with AF, the mortality is very high. OAT is not associated with increased mortality, while antiplatelet drugs are. OAT seems, on the contrary, associated with a better survival; however, it does not decrease the incidence of ischaemic stroke, whereas it increases the incidence of bleeding. Bleeding risk is lower in subjects in whom the INR is kept within the therapeutic range.

Serum uric acid and blood pressure in children at cardiovascular risk.

OBJECTIVES: Hyperuricemia has been shown to be a strong correlate of hypertension in children. However, the complex interaction between serum uric acid (UA), systemic blood pressure (BP), and possibly confounding factors has been elucidated only in part. METHODS: We evaluated office BP as well as clinical and biohumoral parameters in a cross-sectional cohort of 501 children (280 boys and 221 girls) aged between 6 and 18 years (mean = 10.8 years) consecutively referred for cardiovascular risk assessment. RESULTS: Overall, 156 (31.1%) were normotensive, 122 (24.4%) showed transient hypertension, 87 (17.4%) had prehypertension, and 136 (27.1%) had hypertension. Altogether 33.3% and 40.5% of the study group were overweight or obese, respectively. There was a trend toward greater weight and waist circumference and higher BMI, Homeostasis Model Assessment index, and UA levels as the BP categories rose. Moreover, the prevalence of pubertal children, obesity, and waist-to-height ratio above 0.50 progressively increased from lower to upper BP categories. After adjusting for puberty, gender, BMI (z-score), Homeostasis Model Assessment index, and renal function, UA was found to be directly related to systolic and diastolic BP values (P = .03). Using normotensive children for comparison, the risk of showing prehypertension or hypertension increased by at least 50% for each 1 mg/dL UA increase (P < .01), whereas it doubled for children in the top gender-specific UA quartile (P < .03). CONCLUSIONS: Increased UA levels showed an independent predictive power for the presence of higher BP levels among a cohort of children at relatively high cardiovascular risk.

Hypertension, Prehypertension, and Transient Elevated Blood Pressure in Children: Association With Weight Excess and Waist Circumference

BACKGROUND To assess the prevalence of hypertension (H), prehypertension (PH), and transient elevated blood pressure (TH) and their relationship with weight class and waist circumference (WC) in an unselected population of Northern Italian children. METHODS A cross-sectional study was conducted in 5,131 children (5-11 years). Weight class was defined according to the International Obesity Task Force references, H and PH according to the National High Blood Pressure Education Program. A child was classified as having PH or H when systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) at first screening were > or =90th percentile and the mean of three subsequent measures was between the 90th and 95th or > or =95th percentile, respectively. When BP values at the first screening were > or =90th percentile but the mean of three subsequent measures was <90th percentile the child was classified as having TH. RESULTS A proportion of 3.4% presented H, 2.7% PH, and 10.4% TH, 20% overweight, and 6% obesity. Weight class and WC were significantly associated to an increased risk of falling into any of the hypertensive categories. In children with TH BP z-scores of the mean of the three subsequent measurements following the first screening were significantly higher than BP z-scores observed in normotensive children (P value <0.001). CONCLUSIONS Weight class and WC are associated with BP. This is observed not only for H but also for PH, and for nonsustained forms of H. Prospective studies are needed to assess whether children with PH and TH will develop sustained H.

Renorenal reflexes in the rat elicited upon stimulation of renal chemoreceptors

The effects of renal ischemia and backflow of non-diuretic urine into the renal pelvis on renal efferent sympathetic postganglionic nerve activity, femoral arterial pressure and heart rate were studied to verify whether stimulation of renal chemoreceptors elicits autonomic reflexes. In rats with intact spinal cord or spinal cord sectioned at the T6 level a brief activation of renal chemoreceptors produced excitatory ipsilateral and contralateral renorenal reflexes, whereas it only slightly and insignificantly altered arterial pressure and heart rate. These results indicate that stimulation of renal chemoreceptors elicits renorenal excitatory reflexes which might be integrated both at spinal and supraspinal levels.