Prevalence and determinants of blood pressure variability in pygmies of Southern region Cameroon.

INTRODUCTION: The impact of urbanization and living conditions on the prevalence of hypertension in the Cameroonian population is poorly known. AIM: To evaluate the prevalence and determinants of blood pressure (BP) in adult Pygmies and Bantus living in urban and rural areas of Southern Cameroon. PARTICIPANTS AND METHODS: This was a cross-sectional comparative study of 406 adults (96 urban Bantus, 100 urban Pygmies, 111 rural Bantus and 99 tropical rainforest Pygmies with a traditional Pygmies way of life), recruited in Southern Cameroon (mean age 42 ±â€Š17 years; 56.7% women). Sociodemographic, anthropometric and BP parameters were collected. Hypertension was defined as BP at least 140/90 mmHg and/or use of BP-lowering drug(s). RESULTS: The age-standardized prevalence of hypertension in urban Bantus, rural Bantus, urban Pygmies and traditional Pygmies was 18.0, 13.5, 9.3 and 4.1%, respectively. Mean SBP and DBP differed significantly according to Bantu vs. Pygmy ethnicity, and urban vs. rural residency. After multiple adjustments, mean arterial pressure was significantly associated with age, BMI, Bantu ancestry and urban residency. CONCLUSION: Bantu ethnicity and urban residency are significantly associated with high-BP among people from Southern Cameroon.

Association of urinary sodium excretion with blood pressure and risk factors associated with hypertension among Cameroonian pygmies and bantus: a cross-sectional study.

BACKGROUND: High salt intake increases blood pressure (BP) and hypertension risk. This study aimed to examine association of urinary sodium excretion with BP and hypertension correlates among Cameroonian pygmies under hunter-gatherer subsistence mode and Bantus, living in urban area under unhealthy behavioral habits. METHODS: In this cross-sectional cluster sampling study, we randomly enrolled rural pygmies living in Lolodorf and urban Bantus living in Douala. The World Health Organization steps questionnaire was used to collect socio-demographic and lifestyle data. Height, weight, BP and single overnight spot urine samples were obtained in all participants. BP was measured in triplicate. Urinary sodium and potassium excretion was determined by flame photometry. Data were recorded and analyzed using SPSS 16.0. RESULTS: We included 150 Pygmies and 150 Bantus aged 38 ± 12 years and 33 ± 11 years, respectively (p <  0.0001). Compare to Bantus, pygmy's height and weight were respectively: 1.54 ± 0.09 m vs 1.72 ± 0.12 m; and 54.4 ± 9.2 kg vs 77.2 ± 14.8 kg, all p <  0.0001. Age-standardized prevalence of hypertension was 3.3% among Pygmies and 28% among Bantus (p <  0.0001). Age-adjusted systolic and diastolic BP were lower in Pygmies than in Bantus (107 ± 12 vs 119 ± 17 mmHg and 71 ± 11 vs 78 ± 13 mmHg respectively, all P <  0.0001). BP increased with age but to a lesser extent in Pygmies (all p <  0.01). Urinary sodium excretion was lower in Pygmies than in Bantus (46.9 ± 32.4 vs 121.5 ± 61.0 mmol/l, p <  0.0001). Systolic and diastolic BP were positively associated with urinary sodium excretion in Bantus (all p <  0.05). In the two groups, urinary potassium excretion was similar, and was not related to blood pressure. In the total study group and in Bantus taken separately, urinary sodium excretion was higher in hypertensive than in normotensive subjects. Multivariable logistic regression showed that urinary sodium excretion, Bantu status and age emerged as independent determinants of hypertension in the whole study group (OR (95%CI): 1.012 (1.005-1.018); 11.408 (3.599-36.165); 1.095 (1.057-1.135) respectively, p <  0.0001). CONCLUSION: Hunter-gatherer pygmies exhibit low level of urinary sodium excretion related to low rate of hypertension and slower BP increase with age. Salt intake was a major driver of hypertension in our study population. Our findings highlight the need of efforts to implement nationwide prevention programs promoting risk factor screening and healthier lifestyles including reduction of dietary salt intake in Cameroonian.

Prevalence, awareness, treatment, and control of hypertension among rural and urban dwellers of the Far North Region of Cameroon.

OBJECTIVE: To assess the prevalence and determinants of high blood pressure (BP) and awareness, treatment, and control rates in the Far North Region of Cameroon, where these variables have not been explored so far. METHODS: In total, 889 individuals (41.5% women) aged at least 18 years participated in a cross-sectional survey conducted in Maroua (urban area) and Tokombere (rural area) from November 2014 to May 2015, using a multistage cluster sampling frame. Anthropometric variables, BP, and fasting capillary glucose were assessed in all participants. Hypertension was defined as BP at least 140/90 mmHg or antihypertensive therapy and BP control as BP less than 140/90 mmHg. Prevalence estimates were age standardized to the Cameroon population. RESULTS: The prevalence of hypertension was 37.8% (rural: 34%; urban: 41.2%; men: 38.8%; women: 37.9%). Hypertension was associated with urban environment (odds ratio: 1.42; 95%; confidence interval 1.06-1.89), age at least 70 years (4.06; 2.02-6.14), male sex (4.06; 2.02-6.14), abdominal obesity (2.36; 1.54-3.61), and high blood sugar (2.01; 1.31-3.08). Among individuals with hypertension, 18.6% (rural: 17.9%; urban: 19.5%) were aware of having high BP. Among those aware, 29.3% (rural: 17.3%; urban: 36.3%) reported receiving treatment, of whom 16.3% (rural: 22.6%; urban: 4.2%) had BP controlled. Awareness, treatment, and BP control levels were higher in women than men. CONCLUSION: Hypertension is highly prevalent in Far North Cameroon and awareness, treatment, and control rates are low. Efforts to improve detection, treatment, and control of hypertension in Cameroon are needed.

Effects of antiretroviral therapy on arterial stiffness in Cameroonian HIV-infected patients.

BACKGROUND: HIV infection increases cardiovascular risk and highly active antiretroviral therapy may further augment it. We hypothesized that an increase in large artery stiffness may be a mechanism of enhanced cardiovascular risk in treated HIV-infected (HIV-T) patients. MATERIALS AND METHODS: Pulse wave velocity (PWV) and augmentation index (AI) were measured in 108 Cameroonian untreated HIV-infected (HIV-UT) patients and in 130 HIV-T patients. RESULTS: Brachial and aortic systolic blood pressure (BP), diastolic BP, and pulse pressure were higher in HIV-T patients than in HIV-UT patients (all, P < 0.01). PWV was comparable in HIV-T and HIV-UT patients (7.2 ± 1.5 vs. 7.46 ± 2.2 m/s, respectively, P = 0.3), whereas AI was higher in HIV-T patients than in HIV-UT patients (7.9 ± 5 vs. 5.76 ± 4%, respectively, P = 0.003). AI was associated independently with age, brachial systolic BP, brachial diastolic BP, and height in HIV patients (R = 0.75, P < 0.01). CONCLUSION: This study shows that pulse pressure and AI were increased in HIV-T patients, compared with matched HIV-UT patients, suggesting that highly active antiretroviral therapy could increase cardiovascular risk. However, PWV was not accelerated in HIV-T patients.

Effects of hunter-gatherer subsistence mode on arterial distensibility in Cameroonian pygmies.

We aimed to assess whether arterial distensibility estimated by pulse wave velocity (PWV) and augmentation index (AI) differs between Cameroon traditional pygmies (TPs) on hunter-gather subsistence mode, contemporary pygmies who migrated to semiurban area, and the Bantou farmers (BFs) sharing the same environment. For that purpose, we recorded carotid-femoral PWV (ComplioR) in age and sex carefully matched 20 TPs, 20 contemporary pygmies, and 22 BFs. Aortic AI corrected for heart rate and blood pressures were generated from pressure wave analysis (SphygmoCor). Lipid profile was determined in TP and BF participants. TPs were shorter (P=0.02) with lower body weight (P<0.01) in comparison with contemporary pygmies and BFs. TPs had lower low-density lipoprotein cholesterol but higher high-density lipoprotein cholesterol than BFs (P<0.01). Their PWV (5.81±0.21 m/s) was slower (P=0.006) than that of contemporary pygmies (6.82±0.36 m/s) or BFs (6.93±0.29 m/s); however, after its adjustment for age, mean arterial pressure, and heart rate, the difference was slightly attenuated (P=0.051). PWV adjusted for weight did not differ between groups (P=0.10). In the whole study population but not in TPs taken separately, multivariate regression analysis revealed that PWV was independently associated with mean arterial pressure, age, and TP status (P<0.001), whereas age, mean arterial pressure, and height emerged as independent determinants of aortic AI corrected for heart rate (P<0.001). Aortic AI corrected for heart rate did not differ in the 3 groups. In conclusion, hunter-gather lifestyle is associated with low atherosclerosis risk translated by lower aortic stiffness attributed at least partly to low weight and blunted effects of aging and blood pressures on TP arterial structure and function.

[Hypertension in the adult Congolese population of Southern Kivu: Results of the Vitaraa Study]. / Hypertension artérielle chez l'adulte Congolais du Sud Kivu : résultats de l'étude Vitaraa.

OBJECTIVE: To assess the prevalence of cardiovascular risk factors in adult urban and rural Congolese subjects. METHODS: We obtained anthropometric data and information on life habits and medical history in 699 people ≥ 20 years, 444 in an urban, 255 in a rural setting. We determined the body mass index and recorded two blood pressure measurements that were averaged for analysis. Hypertension was BP ≥ 140/90mmHg, awareness and/or use of antihypertensive treatment. Diabetes mellitus was self-reported diagnosis or a casual glycemia ≥ 200mg/dL. We assessed the probability of hypertension in stepwise multiple logistic analysis, and awareness, and control of hypertension. RESULTS: We found higher (P<0.001) prevalence in the urban than the rural subjects for hypertension (41.4% vs 38.1%), diabetes (4.9% vs 3.2%), overweight/obesity (37.6% vs 16.5%), abdominal obesity (30.9% vs 12.9%), use of alcohol (45% vs 17.6%) and smoking (11.6% vs 1.2%). Hypertension was associated (P<0.05) to aging in 51.3%, overweight/obesity in 54.5%, diabetes in 69%, abdominal obesity in 63.8%, low physical activity in 42.4%, to stress in urban environment in 43.2% and professional position (executives: 53.2%, workers: 38.6%). Of these hypertensive subjects, 57.5% were unaware, 30.5% were treated, with control achieved in only 13.6% (17.4% women vs 6.9% men; P<0.01). In the logistic model, the probability of hypertension increased with age (OR for age>55 years: 2.35; P<0.001), overweight/obesity (2.22; P<0.001) and diabetes mellitus (2.67; P<0.05). CONCLUSIONS: Our results indicate a heavy burden of uncontrolled risk factors in the Congolese population the potential complications of which run at a high mortality rate. They highlight the need for reasonable prevention measures at the population level.

Intensified large artery and microvascular response to cold adrenergic stimulation in African blacks.

BACKGROUND: Arterial stiffening is more accelerated in blacks than in whites. Whether this is attributed to an enhanced vascular reactivity to environmental stress stimulation remains unknown. We therefore decided to test the hypothesis that cold pressor test (CPT) elicits a greater increase in arterial stiffness and an enhanced sympathetic skin vasoconstriction in African blacks than in whites normotensives. METHODS: A total of 17 young normotensive African blacks and 17 normotensive whites were recruited. All underwent continuous assessment of blood pressure (BP), heart rate, and carotid-femoral pulse wave velocity (PWVc-f) at rest, during and after hand immersion in iced water (CPT). Concomitantly, skin microvascular blood flow was monitored by laser Doppler flowmetry on the opposite hand. RESULTS: At baseline, African blacks exhibited higher values of PWVc-f than whites (7.2 +/- 0.3 vs. 6.5 +/- 0.2 m/s, respectively, P = 0.04). During CPT the increases in systolic BP and PWVc-f were greater in African blacks than in whites (systolic BP 17 +/- 2 mm Hg vs. 9 +/- 3 mm Hg, P < 0.001 and PWVc-f 0.62 +/- 0.1 m/s vs. 0.26 +/- 0.1 m/s, P = 0.03, respectively). However, there was no significant difference in the PWVc-f responses among the groups during CPT after adjustment for the increments in mean BP. Finally, CPT induced a more pronounced skin microvascular vasoconstriction in African blacks than in whites (-54.4 +/- 5 % vs. -31.3 +/- 6 %, P < 0.001). CONCLUSIONS: CPT provokes a more pronounced increase in PWVc-f in normotensive African blacks than in whites, that appears to be due to a greater increase in mean BP. Additionally, African blacks present an intensified skin microvascular response to the CPT as compared to their whites counterparts.

Myocardial homing and coronary endothelial function after autologous blood CD34+ progenitor cells intracoronary injection in the chronic phase of myocardial infarction.

Transcoronary transplantation of progenitor cells has been proposed as a novel therapy for ischemic heart failure. The primary aims were to assess the feasibility of obtaining CD34+ cells from blood without mobilization in chronic conditions and to compare homing with results reported in acute conditions. We also evaluated the effect of CD34+ on endothelial function. In 7 patients with a history of an anterior myocardial infarction (20 +/- 2 months), a large amount of CD34 (18.2 +/- 3.0 x 10(6)) were obtained and an intracoronary infusion into the left anterior descending artery via an over-the-wire balloon catheter was performed. Myocardial homing involved 3.2% +/- 0.6% of injected cells. Endothelial function studied with increasing doses of bradykinin was not significantly modified after 3 months. In the treated group, compared with 5 nonrandomized control patients with a similar clinical history, the only echocardiographic significant change (2-way analysis of variance) was a decrease in end-systolic volume (P < 0.03). In conclusion, large amounts of CD34+ cells can be obtained from blood, without mobilization, in the chronic phase of myocardial infarction. As reported in the acute situation 1 hour after treatment, intracoronary infusion of CD34+ cells results in myocardial homing of a few percents of the cells. In this small group of patients, no effect of this therapy is detected on the endothelial function and only marginal changes are observed on echocardiographic parameters.

Acute effects of nicotine on arterial stiffness and wave reflection in healthy young non-smokers.

1. Recently, we have demonstrated that cigarette smoke exposure proportionally increases plasma nicotine levels and arterial wave reflection to the aorta. However, the exact contribution of nicotine to the smoke-induced enhancement of wave reflection and the potential underlying mechanisms have not been fully investigated. 2. The present study was a prospective study in 15 healthy male non-smokers. All received a placebo and a 2 mg nicotine tablet, according to a randomized double-blind cross-over study design. Each subject underwent repeated measurements at baseline and for 1 h after nicotine or placebo intake, using carotid-femoral pulse wave velocity (PWV) to assess arterial compliance. Concurrently, aortic pressures and the augmentation index were evaluated using applanation tonometry. 3. Plasma nicotine concentrations achieved 1 h after intake of the nicotine tablet reached comparable levels to those achieved after 1 h exposure to passive smoke (3.6 +/- 0.4 vs 3.2 +/- 0.4 ng/mL, respectively; P = 0.4). 4. Nicotine enhanced arterial wave reflection to the aorta, as assessed by the augmentation index corrected for heart rate (4.2 +/- 1.3 vs-0.7 +/- 0.8% with placebo; P = 0.001). In addition, a progressive increase in carotid-femoral PWV was noted after nicotine administration (0.3 +/- 0.1 vs-0.02 +/- 0.1 m/s with placebo; P = 0.04). This remained significant even after adjustment for changes in mean blood pressure and heart rate (P = 0.01). 5. Plasma nicotine concentrations comparable to those achieved after exposure to passive smoke enhance arterial wave reflection to the aorta. This is accompanied by an increase in carotid-femoral PWV, denoting a deterioration of arterial compliance by nicotine.

Nicotine increases chemoreflex sensitivity to hypoxia in non-smokers.

BACKGROUND: The peripheral chemoreflex contributes to cardiovascular regulation and represents the first line of defence against hypoxia. The effects of nicotine on chemoreflex regulation in non-smoking humans are unknown. METHOD: We conducted a prospective, randomized, crossover, and placebo-controlled study in 20 male non-smokers to test the hypothesis that nicotine increases chemoreflex sensitivity. The effects of two intakes of 2 mg nicotine tabs and placebo on sympathetic nerve activity to muscle circulation (muscle sympathetic nerve activity; MSNA), minute ventilation (Ve), blood pressure and heart rate were assessed during normoxia, moderate isocapnic hypoxia, hyperoxic hypercapnia and an isometric handgrip in 10 subjects. Maximal end-expiratory apnoeas were performed at baseline and at the end of the fifth minute of hypoxia. In a second experimental setting, we studied the ventilatory response to a more marked isocapnic hypoxia in 10 other volunteers. RESULTS: Mean MSNA and Ve were not modified by nicotine during the 5 min of normoxia or moderate hypoxia. In the presence of nicotine MSNA was related to oxygen desaturation (P < 0.01). The sympathoexcitatory effects of nicotine became especially evident when apnoeas achieved oxygen saturations less than 85% (511 +/- 44% increase in MSNA after the first intake, and 436 +/- 43% increase after the second intake versus 387 +/- 56% and 338 +/- 31% with placebo, respectively, P < 0.05). Nicotine also increased the ventilatory response compared with placebo when oxygen saturation decreased to less than 85% (P < 0.05). CONCLUSION: This is the first study to demonstrate that nicotine increases peripheral chemoreflex sensitivity to large reductions in arterial oxygen content in healthy non-smokers.

Sympathoexcitation increases the QT/RR slope in healthy men: differential effects of hypoxia, dobutamine, and phenylephrine.

INTRODUCTION: Dynamic ventricular repolarization assessed by QT/RR slopes studies the effects of modifications in cardiac repolarization independently of variations in RR interval (RR). The effects of changes in sympathetic and vagal activity on the QT/RR slope are controversial. We tested the hypothesis that sympathoexcitation is an important determinant of the QT/RR slope. METHODS AND RESULTS: We compared the effects of a reflex sympathetic activation in response to hypoxia, to the direct effects of the infusion of the beta-adrenergic agent dobutamine, on the QTa (apex) and QTe (end)/RR slopes. Dobutamine was titrated to obtain similar increases in cardiac output than with hypoxia. Cardiac vagal activity was estimated by rMSSD and pNN50. In a second group of healthy subjects, we assessed the effect of a reflex cardiac vagal activation in response to phenylephrine infusion on the same variables. We observed a similar increase in QTa and QTe slopes during hypoxia and dobutamine (both P < 0.017 vs. normoxia), despite divergent changes in cardiac vagal activity, as rMSSD and pNN50 decreased with hypoxia compared to normoxia (P < 0.001) but increased during dobutamine infusion compared to hypoxia (P < 0.017). In contrast, these slopes did not change during the rises in rMSSD and pNN50 elicited by phenylephrine (P > 0.7). CONCLUSION: Beta-adrenergic stimulation induces comparable increases in the QT/RR slopes than hypoxia, but in the presence of a larger cardiac vagal activity. Vagal cardiac activation by phenylephrine does not change the QT slopes. This reveals that the sympathetic system is an important determinant of QT/RR dynamicity in healthy men.

Outcomes in subgroups of hypertensive patients treated with regimens based on valsartan and amlodipine: An analysis of findings from the VALUE trial.

BACKGROUND: In the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial the primary outcome (cardiac morbidity and mortality) did not differ between valsartan and amlodipine-based treatment groups, although systolic blood pressure (SBP) and diastolic blood pressure reductions were significantly more pronounced with amlodipine. Stroke incidence was non-significantly, and myocardial infarction was significantly lower in the amlodipine-based regimen, whereas cardiac failure was non-significantly lower on valsartan. OBJECTIVES: The study protocol specified additional analyses of the primary endpoint according to: sex; age; race; geographical region; smoking status; type 2 diabetes; total cholesterol; left ventricular hypertrophy; proteinuria; serum creatinine; a history of coronary heart disease; a history of stroke or transient ischemic attack; and a history of peripheral artery disease. Additional subgroups were isolated systolic hypertension and classes of antihypertensive agents used immediately before randomization. METHODS: The 15,245 hypertensive patients participating in VALUE were divided into subgroups according to baseline characteristics. Treatment by subgroup interaction analyses were carried out by a Cox proportional hazard model. Within each subgroup, treatment effects were assessed by hazard ratios and 95% confidence intervals. RESULTS: For cardiac mortality and morbidity, the only significant subgroup by treatment interaction was of sex (P = 0.016), with the hazard ratio indicating a relative excess of cardiac events with valsartan treatment in women but not in men, but SBP differences in favour of amlodipine were distinctly greater in women. No other subgroup showed a significant difference in the composite cardiac outcome between valsartan and amlodipine-based treatments. For secondary endpoints, a sex-related significant interaction was found for heart failure (P < 0.0001), with men but not women having a lower incidence of heart failure with valsartan. CONCLUSION: As in the whole VALUE cohort, in no subgroup of patients were there differences in the incidence of the composite cardiac endpoint with valsartan and amlodipine-based treatments, despite a greater blood pressure decrease in the amlodipine group. The only exception was sex, in which the amlodipine-based regimen was more effective than valsartan in women, but not in men, whereas the valsartan regimen was more effective in preventing cardiac failure in men than in women.

Ethnic differences in arterial stiffness and wave reflections after cigarette smoking.

BACKGROUND: Smoking increases plasma nicotine. Nicotine releases catecholamines and alters arterial distensibility. The nicotine intake per cigarette is greater and serum cotinine levels, the proximate metabolite of nicotine, are higher in Blacks than in Whites. We tested the hypothesis that cigarette smoking increases the pulse wave velocity (PWV), a marker of arterial stiffness, and the augmentation index (AI), a measure of wave reflection, more in Blacks than in Whites. METHODS: We matched Black (n = 30) and White (n = 30) smokers for age, gender, body mass index and height. We determined carotid-femoral PWV (PWVCF) and carotid-radial PWV (PWVCR) (Complior), the AI derived from the aortic pressure waveform (applanation tonometry, Sphygmocor), blood pressure, heart rate (HR) and cotinine levels before and after cigarette smoking. We also performed measurements in 16 participants after sham smoking. RESULTS: Smoking increased the AI, PWVCF and PWVCR in the whole population (all P < 0.05, n = 60). Increases in the AI and PWV were positively related to serum cotinine levels (all P < 0.05). Smoking increased serum cotinine (P = 0.01) and mean blood pressure (P = 0.03) more, but raised the HR to a lesser extent, in Blacks [+8 +/- 4 versus +13 +/- 6 beats/min in Whites (mean +/- SD), P = 0.01]. Blacks disclosed larger increases in AI adjusted for HR (Blacks, +7.2 +/- 8 versus Whites, +4.4 +/- 8%; P = 0.03), PWVCF (Blacks, +1.1 +/- 0.2 versus Whites, +0.6 +/- 0.3 m/s; P < 0.01) and PWVCR (Blacks, +1.4 +/- 0.1 versus Whites, +0.7 +/- 0.4 m/s; P < 0.01) normalized for the mean blood pressure. No changes were observed with sham smoking. CONCLUSIONS: Smoking acutely increases the PWV and AI in Blacks more than in Whites. Differences in nicotine metabolism and beta-adrenergic sensitivity could explain these findings.

Increased peripheral chemoreceptors sensitivity and exercise ventilation in heart transplant recipients.

BACKGROUND: Heart failure is characterized by increased ventilation during exercise, which is positively related to increased peripheral and central chemoreceptor sensitivity. Heart transplantation does not normalize the ventilatory response to exercise, and its effects on the chemoreflex control of ventilation remain unknown. We tested the hypothesis that chemoreceptor sensitivity is increased in heart transplant recipients (HTRs) and linked to exercise hyperpnea. METHODS AND RESULTS: We determined the ventilatory, muscle sympathetic nerve activity (MSNA), and circulatory responses to isocapnic hypoxia and hyperoxic hypercapnia 7+/-1 years after transplantation in 19 HTRs with a normal left ventricular ejection fraction of 60+/-2%. Results were compared with those of 11 closely matched referent subjects. Sixteen patients and 10 referent subjects also underwent cycle ergometer exercise tests. HTRs compared with referent subjects presented higher MSNA (52+/-4 versus 34+/-3 bursts/min; P<0.01) and heart rates (83+/-3 versus 68+/-3 bpm; P<0.01) during room air breathing. The ventilatory response to hypoxia was higher in HTRs than in referent subjects (P<0.01, ANOVA). The increase in MSNA also was more marked during hypoxia in the HTRs than in the referent group (P<0.05, ANOVA). Responses to hyperoxic hypercapnia did not differ between the HTRs and the referent group. The ventilatory response to exercise, characterized by the regression slope relating minute ventilation to CO2 output, was steeper in HTRs than in referent subjects (38+/-2 versus 29+/-1 L/mm Hg; P<0.01). Exercise ventilation in HTRs was related to the ventilatory response to isocapnic hypoxia (r=0.57; n=16; P<0.05) and to the ventilatory response to hyperoxic hypercapnia (r=0.50; n=16; P<0.05). CONCLUSIONS: Peripheral chemoreceptor sensitivity is increased in HTRs and is related to exercise hyperpnea after heart transplantation.

Myocardial homing of nonmobilized peripheral-blood CD34+ cells after intracoronary injection.

Granulocyte--colony-stimulating factor administered for autologous hematopoietic stem cell isolation from blood may favor restenosis in patients implanted after acute myocardial infarction (AMI). We therefore tested the isolation of peripheral-blood CD34+ cells without mobilization in six patients with AMI. After large-volume cytapheresis and positive CD34+ cell selection, 3.6 to 27.6 million CD34+ cells were obtained. We performed intra-coronary implantation of these cells and recorded no restenosis or arrhythmia. We used positron emission tomography (PET) to assess myocardial-labeled CD34+ cell homing, which accounted for 5.5% of injected cells 1 hour after implantation. In conclusion, large amounts of CD34+ cells, in the range reported in previous studies, can be obtained from nonmobilized peripheral blood. PET with [18F]-fluorodeoxyglucose cell labeling is an efficient imaging method for homing assessment.

Perindopril/indapamide combination more effective than enalapril in reducing blood pressure and left ventricular mass: the PICXEL study.

OBJECTIVE: Few data are available comparing the effects of monotherapy and combination therapy on target organ damage. The PICXEL study compared the efficacy of a strategy based on first-line combination with perindopril/indapamide versus monotherapy with enalapril in reducing left ventricular hypertrophy (LVH) in hypertensive patients. METHODS: In this 1-year multicentre randomized double-blind study, patients received an increasing dosage of perindopril/indapamide (n = 284) or enalapril (n = 272). Changes in blood pressure and echocardiographic measures of LVH were assessed from baseline to the end of treatment. Reading of the echocardiograms was central and blinded for therapy, patient and sequence. RESULTS: Systolic and diastolic blood pressure decreased significantly more in the perindopril/indapamide than in the enalapril group (P < 0.0001 and P = 0.003). The left ventricular mass index decreased by 13.6 +/- 23.9 g/m(2) (mean +/- SD) with perindopril/indapamide (P < 0.0001) and 3.9 +/- 23.9 g/m(2) with enalapril (P < 0.005); these decreases were significantly different (P < 0.0001). The left ventricular internal diameter, posterior and interventricular septal wall thickness decreased significantly with perindopril/indapamide (P < or = 0.0001); the interventricular septal wall thickness decreased significantly with enalapril (P < 0.001). Both treatments were well tolerated. CONCLUSION: A strategy based on first-line combination with perindopril/indapamide achieved better blood pressure decrease with a significantly greater degree of LVH reduction than a strategy based on monotherapy with enalapril in hypertensive patients with LVH.

Sympathetic nerve activity after thoracoscopic cardiac resynchronization therapy in congestive heart failure.

BACKGROUND: Sympathetic benefits of thoracoscopic cardiac resynchronization therapy (TCRT) in congestive heart failure (CHF) are unknown. We determined cardiac hemodynamics, functional status, and muscle sympathetic nerve activity (MSNA) in a group of TCRT patients. We aimed to compare these patients with CHF patients with cardiac asynchrony (ASY) to substantiate the beneficial effects of TCRT. METHODS AND RESULTS: Eleven patients resynchronized by TCRT 6 +/- 1 months before study inclusion (SYN) and 10 matched ASY patients underwent blood pressure, heart rate, and MSNA recordings. All underwent functional status, cardiac index, and left ventricular ejection fraction (LVEF) assessments. SYN patients had shorter QRS duration and interventricular mechanical delays, longer 6 minute walking distance and lower New York Heart Association class (all P < .05) than ASY patients. MSNA of 56 +/- 2 bursts/min in ASY patients was higher than in SYN patients (48 +/- 3 bursts/min, P < .05). Cardiac index was higher in SYN patients than in ASY patients (2.8 +/- 0.2 versus 1.9 +/- 0.2 L.min.m2, P < .05, respectively). MSNA was highest in the patients with the lowest LVEF (r = -0.49, P < .05), cardiac index (r = -0.48, P < .05) and 6-minute walking distance (r = -0.50, P < .05). CONCLUSION: Lower sympathetic nerve activities in TCRT patients are related to more favorable cardiac indexes and six minute walking distances suggesting a sympathetic, hemodynamic, and functional improvement by TCRT.

Effects of peripheral chemoreceptors deactivation on sympathetic activity in heart transplant recipients.

Heart transplantation initially normalizes sympathetic hyperactivity directed at the muscle circulation. However, sympathetic activity increases with time after transplantation and the exact mechanisms responsible for sympathetic control in heart transplant recipients remain unclear. We examined the effects of peripheral chemoreflex deactivation caused by breathing 100% oxygen on muscle sympathetic nerve activity (expressed as number of burst per minute and mean burst amplitude), heart rate, and mean blood pressure in 13 heart transplant recipients, 13 patients with essential hypertension, and 10 controls. Heart transplant recipients disclosed the highest sympathetic activity, whereas it did not differ between controls and patients with essential hypertension (51+/-16 versus 37+/-14 versus 39+/-12 burst/min, respectively; P<0.05). Breathing 100% oxygen, in comparison with 21% oxygen, reduced sympathetic activity (-4+/-4 versus -1+/-2 burst/min, P<0.01; 85+/-9 versus 101+/-8% of amplitude at baseline, P<0.001) and mean blood pressure (-4+/-5 versus +3+/-6 mm Hg; P<0.05) in heart transplant recipients, decreased sympathetic activity (-4+/-4 versus 0+/-3 burst/min, P<0.05; 90+/-16 versus 101+/-9% of amplitude at baseline, P<0.05) in patients with essential hypertension, but did not reduce sympathetic activity (2+/-4 versus 3+/-3 burst/min, P=NS; 95+/-11 versus 95+/-13% of amplitude at baseline, P=NS) in control subjects. The sympathetic response to hyperoxia was more marked in heart transplant recipients than in controls (85+/-9 versus 95+/-11% of baseline amplitude; P<0.05). The decrease in sympathetic activity was most evident in patients with the longest time after heart transplantation (r=-0.75, P<0.01). In conclusion, tonic chemoreflex activation increases resting muscle sympathetic nerve activity and favors blood pressure elevation after heart transplantation.