Catheter-based radiofrequency renal-nerve ablation in patients with resistant hypertension

This review aims to describe the role and the results of catheter-based renal nerve ablation for the treatment of resistant hypertension. Despite the availability of multiple classes of orally active antihypertensive treatments, resistant hypertension remains an important public health issue in 2012 due to its prevalence and association with target-organ damage and poor prognosis. The failure of purely pharmacological approaches to treat resistant hypertension has stimulated interest in invasive device-based treatments based on old concepts. In the absence of orally active antihypertensive agents, patients with severe and complicated hypertension were widely treated by surgical denervation of the kidney until the 1960s, but this approach was associated with a high incidence of severe adverse events and a high mortality rate. A new catheter system using radiofrequency energy has been developed, allowing an endovascular approach to renal denervation and providing patients with resistant hypertension with a new therapeutic option that is less invasive than surgery and can be performed rapidly under local anaesthesia. To date, this technique has been evaluated only in open-label trials including small numbers of highly selected resistant hypertensive patients with suitable renal artery anatomy. The available evidence suggests a favourable blood pressure-lowering effect in the short term (6 months) and a low incidence of immediate local and endovascular complications. This follow-up period is, however, too short for the detection of rare or late-onset adverse events. For the time being, the benefit/risk ratio of this technique remains to be evaluated, precluding its uncontrolled and widespread use in routine practice.     

Maternal effects and perinatal safety of labetalol in the treatment of hypertension in pregnancy. Comparison with methyldopa in a randomized cooperative trial

Labetalol was compared with methyldopa in a randomised trial involving 176 pregnant women with mild to moderate hypertension. Effective blood pressure control (diastolic pressure below 86 mmHg) was obtained in a similar proportion of mothers given labetalol or methyldopa, but the addition of a complementary treatment to achieve control was less frequently needed in the labetalol than in the methyldopa group (12/91 vs 22/85 p less than 0.05). Side effects were mild and resulted in discontinuation of the randomised treatment in 1 mother given labetalol. Pregnancy was terminated by intrauterine death in 4 mothers given methyldopa, and one neonate born to a patient allocated to labetalol died at day 1. The average birthweight and the proportion of premature delivery or of small for gestational age newborns were similar in both treatment groups. Heart rate, blood pressure, respiratory rate and blood glucose did not differ between infants born to the mothers of the labetalol and the methyldopa groups, irrespective of gestational age at birth or birthweight. Blood pressure control is more frequently achieved in hypertensive pregnancies with labetalol than with methyldopa as a first line treatment. Labetalol is safe to the fetus and newborn and might offer a better prevention of intrauterine death than methyldopa.     

Influence of steel factor on hemoglobin synthesis in sickle cell disease.

A new hematopoietic growth factor (Steel factor) has been identified which stimulates erythroid proliferation both in vitro and in vivo. We evaluated the influence of recombinant Steel factor on hemoglobin synthesis in peripheral blood (PB) BFU-E-derived cells from normal donors by radioimmunoassay (RIA) and compared it with stimulation with GM-CSF and interleukin-3 (IL-3). Only Steel factor stimulated a significant increase in BFU-E-derived colony size and a significant increase in fetal hemoglobin (HbF) in BFU-E-derived erythroblasts from 0.49% +/- 0.27% to 6.33% +/- 1.11% in serum-deprived media and from 1.88% +/- 0.24% to 11.17% +/- 0.91% in serum. To determine whether this influence on hemoglobinization also occurred in sickle cell disease, we studied 13 patients with sickle cell disease. In serum-deprived conditions, there was a significant increase in the number and size of BFU-E-derived colonies with Steel factor that was dose-dependent. In addition, the proportion of HbF in progenitor-derived cells increased by 66% from 4.1% +/- 0.6% to 6.8% +/- 1.2% with Steel factor. In serum-containing conditions studied in 12 patients, the increase in percentage of HbF was even greater, from 10.7% +/- 0.9% in control cultures to 22.5% +/- 2.6% with Steel factor. These increases in percentage of HbF were significant and dose-dependent. An increase in percentage of HbF was observed in erythroblasts harvested on day 11, 14, and 18 of culture. A decrease in mean picograms of total Hb per cell after coculture with Steel factor was noted, suggesting that growth kinetics influenced complete hemoglobinization. In serum-deprived conditions, picograms of HbF per cell was not affected by Steel factor, and in serum-containing conditions that augment in vitro HbF production it was enhanced. Thus, Steel factor stimulated a significant increase in percentage of HbF in erythroid cells from normal donors and patients with SCA in vitro.     

Comparison of nurse- and physician-determined clinic blood pressure levels in patients referred to a hypertension clinic: implications for subsequent management

BACKGROUND: When measuring BP, the physician induces a transient pressor response triggered by an alarm reaction. This 'white-coat effect' can influence therapeutic decisions. Whether it depends on the characteristics of the physician has not been evaluated. OBJECTIVE: To assess the 'white-coat effect' induced by several physicians in a large sample of patients, using the blood pressure measured by trained nurses as a reference. SETTING: Referral hypertension clinic. METHODS: Patients were selected for the study if they had been referred for the first time to the clinic and if they had had their supine systolic/diastolic blood pressure measured by a trained nurse (mean of the last two of three measurements taken every 1 min by an oscillometric device) and a physician (auscultatory method using a standard mercury sphygmomanometer). Physicians were included in the study provided they had seen at least 25 patients during the study period. The between-physician difference was assessed using linear regression analysis. Physician blood pressure was the dependent and nurse blood pressure was the independent variable. RESULTS: From 1 January 1997 to 15 September 1997, 1062 patients (50% male, aged 52 +/- 14 years), seen by 10 physicians (26-187 patients per physician) and one nurse were included for analysis. The mean systolic/diastolic blood pressure for physicians was 162 +/- 27/ 97 +/- 15 mmHg and that for the nurse was 155 +/- 24/ 88 +/- 14 mmHg. The nurse-physician differences were -6 mmHg (range -67 to +66) for systolic and -8 mmHg (-44 to +31) for diastolic blood pressures. Major differences were observed between individual physicians. Intercepts of the physician blood pressure versus nurse blood pressure relationship ranged from 0.1 -60.7 mmHg for systolic and from 13.3-55.3 mmHg for diastolic pressures. The slopes of this relationship differed less between physicians for systolic (0.72-1) than for diastolic pressures (0.56-0.97). There was no difference between the patients seen by physicians in patients' age, sex, tobacco consumption, anti-hypertensive treatment or target-organ damage. CONCLUSION: Large between-physician differences exist in the magnitude of the white-coat effect that cannot be explained by patient characteristics. Physicians should therefore not make any decisions based on blood pressure measured manually during a first encounter.     

Effects of captopril and minoxidil on left ventricular hypertrophy in resistant hypertensive patients: a 6 month double-blind comparison

In a double-blind 6 month trial, the cardiac effects of captopril and minoxidil, administered as third step treatments, were compared in 34 men with essential hypertension and diastolic blood pressure greater than 95 mm Hg who were taking 200 mg/day of metoprolol and 80 mg/day of furosemide. Average daily doses of captopril and minoxidil were 269 mg (range 150 to 300) and 20 mg (range 7.5 to 30), respectively. At the end of the 6 months' treatment, blood pressure had dropped significantly in both groups, but echocardiographic criteria of hypertrophy improved only in the captopril group (intragroup comparison): blood pressure, thickness of the intraventricular septum and posterior wall, and the left ventricular mass index, respectively, decreased from 163/102 to 135/89 mm Hg (p less than 0.001), 17.4 to 15.9 mm (p less than 0.05), 14.5 to 13.4 mm (p less than 0.05) and 236 to 198 g/m2 (p less than 0.001). In the minoxidil group, blood pressure dropped from 160/99 to 137/87 mm Hg (p less than 0.001), but echocardiographic criteria were not significantly modified. Fractional shortening remained normal in both groups. These results show that in patients with severe left ventricular hypertrophy, captopril-based triple therapy reduces left ventricular mass without altering systolic performance, whereas minoxidil-based therapy does not.     

Meeting breastfeeding intentions differ by race/ethnicity,Infant and Toddler Feeding Practices Study‐2

Prenatal breastfeeding intentions impact breastfeeding practices. Racial/ethnic disparities exist in breastfeeding rates; it is unknown if prenatal intentions and meeting intentions differ by race/ethnicity. A longitudinal cohort of USDA''s Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) which enrolled participants beginning in 2013 were used to estimate prenatal intentions for breastfeeding initiation, exclusive breast milk feeds at 1 and 3 months by race/ethnicity (n = 2070). Meeting intentions were determined by reported breast milk consumption at birth, 1 month and 3 months. Multivariable logistic regression was used to determine the association of race/ethnicity with meeting intentions. There were no differences in prenatal breastfeeding intentions between non‐Hispanic White and non‐Hispanic Black women (initiation: 86.9% and 87.2%; Month 1: 52.3% and 48.3%; Month 3: 43.8% and 40.9%; respectively), but a higher percentage of Hispanic women intended to breastfeed at all time points (95.5%, 68.3% and 56.4%; respectively, P < 0.05). Among women who intended to breastfeed at Month 1, non‐Hispanic Black and Hispanic women had significantly lower odds of meeting intentions compared with non‐Hispanic White women after adjusting for covariates (aORs: 0.63 [95% CI: 0.41, 0.98]; 0.64 [95% CI: 0.44, 0.92], respectively). Similar findings were seen for Month 3. Despite no differences in breastfeeding intentions, non‐Hispanic Black women were less likely to meet their breastfeeding intentions than non‐Hispanic White women. Hispanic women were more likely to intend to breastfeed yet were less likely to meet their intentions. This suggests that non‐Hispanic Black and Hispanic women face challenges to meeting their longer breastfeeding intentions. Understanding how racism, bias and discrimination contribute to women not meeting their breastfeeding intentions may help efforts to reduce breastfeeding disparities.