Cardio-Ankle Vascular Index as a Marker of Left Ventricular Hypertrophy in Treated Hypertensives: Findings From the Pamela Study.

BACKGROUND: Findings regarding the association between Cardio-Ankle Vascular Index (CAVI) and cardiac hypertension-mediated organ damage (HMOD), such as left ventricular hypertrophy (LVH) assessed by echocardiography, in elderly hypertensive patients are scanty. We sought to investigate this issue in the hypertensive fraction of the general population treated with anti-hypertensive drugs enrolled in the Pressioni Monitorate E Loro Associazioni (PAMELA) study. METHODS: The study included 239 out of 562 participants who attended the second and third surveys of the PAMELA study performed after 10 and 25 years from the initial evaluation. Data collection included medical history, anthropometric parameters, office, home, ambulatory blood pressure (BP), blood examinations, echocardiography, and CAVI measurements. RESULTS: In the whole study sample (age 69 ±â€…9 years, 54% males), CAVI was positively correlated with age, office, home, ambulatory systolic BP, LV mass (LVM) index, and negatively associated with body mass index (BMI). In multivariate analysis, CAVI was associated with the LVM index (P < 0.05) independently of major confounders. The participants with LVH exhibited significantly higher CAVI (10.6 ±â€…2.8 vs. 9.2 ±â€…1.8 m/s P < 0.001), larger left atrial diameter, and lower LV ejection fraction values than their counterparts without it. The CAVI value of 9.4 m/s was the best cut-off for prediction of LVH in the whole sample. CONCLUSIONS: Our study provides new evidence of an independent association between CAVI and LVH in treated elderly hypertensive patients and suggests that the use of this metric of arterial stiffness could not only be used to evaluate vascular damage but also to stratify the risk of LVH.

Mechanisms of Vascular Inflammation and Potential Therapeutic Targets: A Position Paper From the ESH Working Group on Small Arteries.

Inflammatory responses in small vessels play an important role in the development of cardiovascular diseases, including hypertension, stroke, and small vessel disease. This involves various complex molecular processes including oxidative stress, inflammasome activation, immune-mediated responses, and protein misfolding, which together contribute to microvascular damage. In addition, epigenetic factors, including DNA methylation, histone modifications, and microRNAs influence vascular inflammation and injury. These phenomena may be acquired during the aging process or due to environmental factors. Activation of proinflammatory signaling pathways and molecular events induce low-grade and chronic inflammation with consequent cardiovascular damage. Identifying mechanism-specific targets might provide opportunities in the development of novel therapeutic approaches. Monoclonal antibodies targeting inflammatory cytokines and epigenetic drugs, show promise in reducing microvascular inflammation and associated cardiovascular diseases. In this article, we provide a comprehensive discussion of the complex mechanisms underlying microvascular inflammation and offer insights into innovative therapeutic strategies that may ameliorate vascular injury in cardiovascular disease.

Serum Uric Acid/Serum Creatinine Ratio and Cardiovascular Mortality in Diabetic Individuals-The Uric Acid Right for Heart Health (URRAH) Project.

Several studies have detected a direct association between serum uric acid (SUA) and cardiovascular (CV) risk. In consideration that SUA largely depends on kidney function, some studies explored the role of the serum creatinine (sCr)-normalized SUA (SUA/sCr) ratio in different settings. Previously, the URRAH (URic acid Right for heArt Health) Study has identified a cut-off value of this index to predict CV mortality at 5.35 Units. Therefore, given that no SUA/sCr ratio threshold for CV risk has been identified for patients with diabetes, we aimed to assess the relationship between this index and CV mortality and to validate this threshold in the URRAH subpopulation with diabetes; the URRAH participants with diabetes were studied (n = 2230). The risk of CV mortality was evaluated by the Kaplan-Meier estimator and Cox multivariate analysis. During a median follow-up of 9.2 years, 380 CV deaths occurred. A non-linear inverse association between baseline SUA/sCr ratio and risk of CV mortality was detected. In the whole sample, SUA/sCr ratio > 5.35 Units was not a significant predictor of CV mortality in diabetic patients. However, after stratification by kidney function, values > 5.35 Units were associated with a significantly higher mortality rate only in normal kidney function, while, in participants with overt kidney dysfunction, values of SUA/sCr ratio > 7.50 Units were associated with higher CV mortality. The SUA/sCr ratio threshold, previously proposed by the URRAH Study Group, is predictive of an increased risk of CV mortality in people with diabetes and preserved kidney function. While, in consideration of the strong association among kidney function, SUA, and CV mortality, a different cut-point was detected for diabetics with impaired kidney function. These data highlight the different predictive roles of SUA (and its interaction with kidney function) in CV risk, pointing out the difference in metabolic- and kidney-dependent SUA levels also in diabetic individuals.

Triglyceride-glucose Index and Mortality in a Large Regional-based Italian Database (Urrah Project).

PURPOSE: Recently, a novel index (triglyceride-glucose index-TyG) was considered a surrogate marker of insulin resistance (IR); in addition, it was estimated to be a better expression of IR than widely used tools. Few and heterogeneous data are available on the relationship between this index and mortality risk in non-Asian populations. Therefore, we estimated the predictive role of baseline TyG on the incidence of all-cause and cardiovascular (CV) mortality in a large sample of the general population. Moreover, in consideration of the well-recognized role of serum uric acid (SUA) on CV risk and the close correlation between SUA and IR, we also evaluated the combined effect of TyG and SUA on mortality risk. METHODS: The analysis included 16,649 participants from the URRAH cohort. The risk of all-cause and CV mortality was evaluated by the Kaplan-Meier estimator and Cox multivariate analysis. RESULTS: During a median follow-up of 144 months, 2569 deaths occurred. We stratified the sample by the optimal cut-off point for all-cause (4.62) and CV mortality (4.53). In the multivariate Cox regression analyses, participants with TyG above cut-off had a significantly higher risk of all-cause and CV mortality, than those with TyG below the cut-off. Moreover, the simultaneous presence of high levels of TyG and SUA was associated with a higher mortality risk than none or only one of the two factors. CONCLUSIONS: The results of this study indicate that these TyG (a low-cost and simple non-invasive marker) thresholds are predictive of an increased risk of mortality in a large and homogeneous general population. In addition, these results show a synergic effect of TyG and SUA on the risk of mortality.

Renal Denervation in End-Stage Renal Disease: Current Evidence and Perspectives.

In patients with end-stage renal disease (ESRD) undergoing haemodialysis, hypertension is of common detection and frequently inadequately controlled. Multiple pathophysiological mechanisms are involved in the development and progression of the ESRD-related high blood pressure state, which has been implicated in the increased cardiovascular risk reported in this hypertensive clinical phenotype. Renal sympathetic efferent and afferent nerves play a relevant role in the development and progression of elevated blood pressure values in patients with ESRD, often leading to resistant hypertension. Catheter-based bilateral renal nerves ablation has been shown to exert blood pressure lowering effects in resistant hypertensive patients with normal kidney function. Promising data on the procedure in ESRD patients with resistant hypertension have been reported in small scale pilot studies. Denervation of the native non-functioning kidney's neural excitatory influences on central sympathetic drive could reduce the elevated cardiovascular morbidity and mortality seen in ESRD patients. The present review article will focus on the promising results obtained with renal denervation in patients with ESRD, its mechanisms of action and future perspectives in these high risk patients.

Prognostic Value and Relative Cutoffs of Triglycerides Predicting Cardiovascular Outcome in a Large Regional-Based Italian Database.

BACKGROUND: Despite longstanding epidemiologic data on the association between increased serum triglycerides and cardiovascular events, the exact level at which risk begins to rise is unclear. The Working Group on Uric Acid and Cardiovascular Risk of the Italian Society of Hypertension has conceived a protocol aimed at searching for the prognostic cutoff value of triglycerides in predicting cardiovascular events in a large regional-based Italian cohort. METHODS AND RESULTS: Among 14 189 subjects aged 18 to 95 years followed-up for 11.2 (5.3-13.2) years, the prognostic cutoff value of triglycerides, able to discriminate combined cardiovascular events, was identified by means of receiver operating characteristic curve. The conventional (150 mg/dL) and the prognostic cutoff values of triglycerides were used as independent predictors in separate multivariable Cox regression models adjusted for age, sex, body mass index, total and high-density lipoprotein cholesterol, serum uric acid, arterial hypertension, diabetes, chronic renal disease, smoking habit, and use of antihypertensive and lipid-lowering drugs. During 139 375 person-years of follow-up, 1601 participants experienced cardiovascular events. Receiver operating characteristic curve showed that 89 mg/dL (95% CI, 75.8-103.3, sensitivity 76.6, specificity 34.1, P<0.0001) was the prognostic cutoff value for cardiovascular events. Both cutoff values of triglycerides, the conventional and the newly identified, were accepted as multivariate predictors in separate Cox analyses, the hazard ratios being 1.211 (95% CI, 1.063-1.378, P=0.004) and 1.150 (95% CI, 1.021-1.295, P=0.02), respectively. CONCLUSIONS: Lower (89 mg/dL) than conventional (150 mg/dL) prognostic cutoff value of triglycerides for cardiovascular events does exist and is associated with increased cardiovascular risk in an Italian cohort.

Regional and temporal differences in the associations between cardiovascular disease and its classic risk factors: an analysis of 49 cohorts from 11 European countries.

AIMS: The regional and temporal differences in the associations between cardiovascular disease (CVD) and its classic risk factors are unknown. The current study examined these associations in different European regions over a 30-year period. METHODS AND RESULTS: The study sample comprised 553 818 individuals from 49 cohorts in 11 European countries (baseline: 1982-2012) who were followed up for a maximum of 10 years. Risk factors [sex, smoking, diabetes, non-HDL cholesterol, systolic blood pressure (BP), and body mass index (BMI)] and CVD events (coronary heart disease or stroke) were harmonized across cohorts. Risk factor-outcome associations were analysed using multivariable-adjusted Cox regression models, and differences in associations were assessed using meta-regression. The differences in the risk factor-CVD associations between central Europe, northern Europe, southern Europe, and the UK were generally small. Men had a slightly higher hazard ratio (HR) in southern Europe (P = 0.043 for overall difference), and those with diabetes had a slightly lower HR in central Europe (P = 0.022 for overall difference) compared with the other regions. Of the six CVD risk factors, minor HR decreases per decade were observed for non-HDL cholesterol [7% per mmol/L; 95% confidence interval (CI), 3-10%] and systolic BP (4% per 20 mmHg; 95% CI, 1-8%), while a minor HR increase per decade was observed for BMI (7% per 10 kg/m2; 95% CI, 1-13%). CONCLUSION: The results demonstrate that all classic CVD risk factors are still relevant in Europe, irrespective of regional area. Preventive strategies should focus on risk factors with the greatest population attributable risk.

All classic cardiovascular disease (CVD) risk factors are still relevant in Europe, irrespective of regional area. The differences in the associations of CVD risk factors with overt CVD between regions of Europe are generally small. Minor temporal hazard decreases were observed for non-HDL cholesterol and systolic blood pressure, while a minor hazard increase was observed for body mass index.

Long-term increase in serum uric acid and its predictors over a 25 year follow-up: Results of the PAMELA study.

BACKGROUND AND AIMS: Hyperuricemia (HU) has been shown to be associated with an adverse impact on cardiovascular and metabolic risk. Scanty data are available in the general population on the longitudinal changes in serum uric acid (SUA), the occurrence of HU and their potential predictors. We examined during a 25-year follow-up the SUA changes and the factors associated with HU development in the Pressioni Arteriose Monitorate E loro Associazioni (PAMELA) study. METHODS AND RESULTS: We analyzed data collected in 561 subjects of the PAMELA study evaluated during an average follow-up time amounting to 25.4 ± 1.0 years (mean ± SD). HU was defined by the Uric Acid Right for Heart Health (URRAh) cutoff (5.1 for females and 5.6 mg/dl for males). Mean SUA values during follow-up increased from 4.7 ± 1.1 to 5.0 ± 1.2 mg/dl (P<0.001), the average SUA elevation amounting to of 0.3 ± 1.1 mg/dl 26.7 % of the subjects displayed HU at the follow-up. This was associated at the multivariable analysis with female gender, office, home and 24-h blood pressure, diuretic treatment, serum triglycerides and baseline SUA, as well as the increase in waist circumference and the reduction in renal function. CONCLUSION: The present study provides longitudinal evidence that in the general population during a 25 year follow-up there is a progressive increase in SUA and HU development. Baseline SUA represents the most important factor associated with these modifications. Gender, renal dysfunction, triglycerides, obesity, diuretic treatment and blood pressure represent other variables capable to predict future occurrence of HU.

Comparison between visit-to-visit office and 24-h blood pressure variability in treated hypertensive patients.

OBJECTIVES: In any treated hypertensive patient office blood pressure (BP) values may differ between visits and this variability (V) has an adverse prognostic impact. However, little information is available on visit-to-visit 24-h BPV. METHODS: In 1114 hypertensives of the ELSA and PHYLLIS trials we compared visit-to-visit office and 24-h mean BPV by coefficient of variation (CV) of the mean systolic (S) and diastolic (D) BP obtained from yearly measurements during a 3-4 year treatment period. Visit-to-visit BPV during daytime and night-time were also compared. RESULTS: Twenty-four-hour SBP-CV was about 20% less than office SBP-CV ( P  < 0.0001). SBP-CV was considerably greater for the night-time than for the daytime period (20%, P  < 0.0001). Results were similar for DBP and in males and females, older and younger patients, patients under different antihypertensive drugs or with different baseline or achieved BP values. In the group as a whole and in subgroups there was significant correlations between office and 24-h BP-CV but the correlation coefficients was weak, indicating that office SBP or DBP CV accounted for only about 1-4% of 24-h SBP or DBP-CV values. CONCLUSION: Twenty-four-hour mean BP across visits is more stable than across visit office BP. Visit-to-visit office and 24-h BPV are significantly related to each other, but correlation coefficients are low, making visit-to-visit office BP variations poorly predictive of the concomitant 24-h BP variations and thus of on-treatment ambulatory BP stability.

The Results of the URRAH (Uric Acid Right for Heart Health) Project: A Focus on Hyperuricemia in Relation to Cardiovascular and Kidney Disease and its Role in Metabolic Dysregulation.

The relationship between Serum Uric Acid (UA) and Cardiovascular (CV) diseases has already been extensively evaluated, and it was found to be an independent predictor of all-cause and cardiovascular mortality but also acute coronary syndrome, stroke and heart failure. Similarly, also many papers have been published on the association between UA and kidney function, while less is known on the role of UA in metabolic derangement and, particularly, in metabolic syndrome. Despite the substantial number of publications on the topic, there are still some elements of doubt: (1) the better cut-off to be used to refine CV risk (also called CV cut-off); (2) the needing for a correction of UA values for kidney function; and (3) the better definition of its role in metabolic syndrome: is UA simply a marker, a bystander or a key pathological element of metabolic dysregulation?. The Uric acid Right for heArt Health (URRAH) project was designed by the Working Group on uric acid and CV risk of the Italian Society of Hypertension to answer the first question. After the first papers that individuates specific cut-off for different CV disease, subsequent articles have been published responding to the other relevant questions. This review will summarise most of the results obtained so far from the URRAH research project.

Anthropometric Measures of Adiposity as Markers of Kidney Dysfunction: A Cross-Sectional Study.

The present study was designed to provide information on the ability of several different anthropometric markers to reflect the renal impairment associated with body weight increase and to predict the development of renal alterations linked to overweight and obesity. In 574 subjects representative of the general population of the Pressioni Arteriose Monitorate e Loro Associazioni (PAMELA) study, with an age range between 57 and 73 years, we investigated the association between different anthropometric markers of body fat, as alternative to body mass index, and renal failure, to obtain information useful for determining their potential predictive value. Renal dysfunction was significantly associated with almost all anthropometric markers of adiposity related to body weight and body shape. After adjustment for confounders, such as age, sex, office blood pressure, serum glucose, antihypertensive drugs and smoking habit, association remained significant only for waist-to-hip ratio (WHR), lipid accumulation product (LAP) and visceral adiposity index (VAI). These 3 markers also displayed at the receiver operating curves (ROC) analysis the best ability to detect subjects with or without kidney dysfunction. The results of the present study provide evidence that WHR, LAP and VAI represent the best markers of renal dysfunction associated with visceral body fat accumulation.

High blood pressure with elevated resting heart rate: a high risk "Sympathetic" clinical phenotype.

Epidemiological studies have unequivocally shown that elevated heart rate values measured at rest have an adverse prognostic impact in the hypertensive patient, being associated with an increased risk of cardiovascular events and complications. In recent years new data have been collected on this issue, strengthening the clinical relevance of elevated heart rate as a specific hypertensive phenotype. The present paper will review old and new data on the prognostic importance of resting tachycardia in the hypertensive patient. It will also examine the role of the sympathetic nervous system in the development of this alteration as well as its therapeutic implications. The different approaches to dynamically assess heart rate values in the clinical setting will be finally discussed.

Sympathetic Neural Mechanisms in Hypertension: Recent Insights.

PURPOSE OF REVIEW: To examine published and unpublished data documenting the role of sympathetic neural factors in the pathogenesis of different hypertensive phenotypes. These phenotypes relate to attended or unattended blood pressure measurements, to nighttime blood pressure profile alterations, and to resistant, pseudoresistant, and refractory hypertension. Results of original clinical studies as well as of recent meta-analyses based on the behavior of different sympathetic biomarkers in various hypertensive forms will be also discussed. RECENT FINDINGS: Studies performed in the past decade have shown that office blood pressure measurements, including in recent years those characterizing unattended or attended blood pressure assessment, are associated with profound changes in the behavior of different sympathetic biomarkers. This is the case for the clinical hypertensive phenotypes characterized by alterations in the nocturnal blood pressure profile and by sleep duration abnormalities. This is also the case for the clinical conditions defined as resistant, refractory, and pseudoresistant hypertension. Data reviewed in the present paper highlight the relevance of sympathetic neural factors in the development and progression of different clinical hypertensive phenotypes. This suggests that a common hallmark of the majority of the essential hypertensive states detectable in current clinical practice is represented by the alteration in the sympathetic blood pressure control.

Coffee consumption, clinic, 24-hour and home blood pressure. Findings from the PAMELA study.

BACKGROUND AND AIMS: Chronic coffee consuption has been reported to be associated with a modest but significant increase in blood pressure (BP), although some recent studies have shown the opposite. These data, however, largely refer to clinic BP and virtually no study evaluated cross-sectionally the association between chronic coffee consuption, out-of-office BP and BP variability. METHODS AND RESULTS: In 2045 subjects belonging to the population of the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study, we analyzed cross-sectionally the association between clinic, 24-hour, home BP and BP variability and level of chronic coffee consumption. Results show that when adjusted for confounders (age, gender, body mass index, cigarette smoking, physical activity and alcohol drinking) chronic coffee consumption does not appear to have any major lowering effect on BP values, particulary when they are assessed via 24-hour ambulatory (0 Cup/day: 118.5 ± 0.7/72.8 ± 0.4 mmHg vs 3 cups/day: 120.2 ± 0.4/74.8 ± 0.3 mmHg, PNS) or home BP monitoring (0 cup/day: 124.1 ± 1.2/75.4 ± 0.7 mmHg vs 3 cups/day: 123.3 ± 0.6/76.4 ± 0.36 mmHg, PNS). However, daytime BP was significantly higher in coffee consumers (about 2 mmHg), suggesting some pressor effects of coffee which vanish during nighttime. Both BP and HR 24-hour HR variability were unaffected. CONCLUSION: Thus chronic coffee consumption does not appear to have any major lowering effect either on absolute BP values, particulary when they are assessed via 24-hour ambulatory or home BP monitoring, or on 24-hour BP variability.

The importance of microvascular inflammation in ageing and age-related diseases: a position paper from the ESH working group on small arteries, section of microvascular inflammation.

Microcirculation is pervasive and orchestrates a profound regulatory cross-talk with the surrounding tissue and organs. Similarly, it is one of the earliest biological systems targeted by environmental stressors and consequently involved in the development and progression of ageing and age-related disease. Microvascular dysfunction, if not targeted, leads to a steady derangement of the phenotype, which cumulates comorbidities and eventually results in a nonrescuable, very high-cardiovascular risk. Along the broad spectrum of pathologies, both shared and distinct molecular pathways and pathophysiological alteration are involved in the disruption of microvascular homeostasis, all pointing to microvascular inflammation as the putative primary culprit. This position paper explores the presence and the detrimental contribution of microvascular inflammation across the whole spectrum of chronic age-related diseases, which characterise the 21st-century healthcare landscape. The manuscript aims to strongly affirm the centrality of microvascular inflammation by recapitulating the current evidence and providing a clear synoptic view of the whole cardiometabolic derangement. Indeed, there is an urgent need for further mechanistic exploration to identify clear, very early or disease-specific molecular targets to provide an effective therapeutic strategy against the otherwise unstoppable rising prevalence of age-related diseases.

Endothelial, Vascular and Sympathetic Alterations as Therapeutic Targets in Chronic Heart Failure.

Vascular and sympathetic abnormalities characterize chronic heart failure (CHF). Alterations include (1) a reduction in arterial distensibility, (2) endothelial dysfunction, (3) a decrease in arterial compliance and a parallel increase in arterial stiffness, and (4) sympathetic cardiovascular activation. Altogether, these alterations represent important targets in therapeutic interventions, because they display an independent negative impact on the disease prognosis, favouring disease progression and the development of cardiovascular complications with direct and indirect mechanisms. The present review will examine the effects of the different therapeutic interventions targeting the vascular/sympathetic alterations detected in CHF. Non-pharmacological, pharmacological and device-based treatments will be discussed in detail, highlighting the possible mechanisms responsible for the vascular/sympathetic effects of each intervention. Finally, the unmet goals in treatment in relation to endothelial and adrenergic targets will be also discussed.

Serum Uric Acid Predicts All-Cause and Cardiovascular Mortality Independently of Hypertriglyceridemia in Cardiometabolic Patients without Established CV Disease: A Sub-Analysis of the URic acid Right for heArt Health (URRAH) Study.

High serum uric acid (SUA) and triglyceride (TG) levels might promote high-cardiovascular risk phenotypes across the cardiometabolic spectrum. However, SUA predictive power in the presence of normal and high TG levels has never been investigated. We included 8124 patients from the URic acid Right for heArt Health (URRAH) study cohort who were followed for over 20 years and had no established cardiovascular disease or uncontrolled metabolic disease. All-cause mortality (ACM) and cardiovascular mortality (CVM) were explored by the Kaplan-Meier estimator and Cox multivariable regression, adopting recently defined SUA cut-offs for ACM (≥4.7 mg/dL) and CVM (≥5.6 mg/dL). Exploratory analysis across cardiometabolic subgroups and a sensitivity analysis using SUA/serum creatinine were performed as validation. SUA predicted ACM (HR 1.25 [1.12-1.40], p < 0.001) and CVM (1.31 [1.11-1.74], p < 0.001) in the whole study population, and according to TG strata: ACM in normotriglyceridemia (HR 1.26 [1.12-1.43], p < 0.001) and hypertriglyceridemia (1.31 [1.02-1.68], p = 0.033), and CVM in normotriglyceridemia (HR 1.46 [1.23-1.73], p < 0.001) and hypertriglyceridemia (HR 1.31 [0.99-1.64], p = 0.060). Exploratory and sensitivity analyses confirmed our findings, suggesting a substantial role of SUA in normotriglyceridemia and hypertriglyceridemia. In conclusion, we report that SUA can predict ACM and CVM in cardiometabolic patients without established cardiovascular disease, independent of TG levels.

Effects of Renal Denervation on Sympathetic Nerve Traffic and Correlates in Drug-Resistant and Uncontrolled Hypertension: A Systematic Review and Meta-Analysis.

BACKGROUND: Whether and to what extent the reported blood pressure (BP) lowering effects of renal denervation (RDN) are associated with a central sympathoinhibition is controversial. We examined this issue by performing a meta-analysis of the microneurographic studies evaluating the BP and muscle sympathetic nerve activity (MSNA) responses to RDN in drug-resistant or uncontrolled hypertension (RHT). METHODS: This analysis comprised 11 studies including a total of >400 RHT patients undergoing RDN and were followed up for 6 months. Evaluation was extended to the relationships of MSNA with clinic heart rate and BP changes associated with RDN. RESULTS: MSNA showed a significant reduction after RDN (-4.78 bursts/100 heart beats; P<0.04), which was also accompanied by a significant systolic (-11.45 mm Hg; P<0.002) and diastolic (-5.24 mm Hg; P=0.0001) BP decrease. No significant quantitative relationship was found between MSNA and systolic (r=-0.96, P=0.19) or diastolic BP (r=-0.97, P=0.23) responses to RDN. This was also the case for clinic heart rate (r=0.53, P=0.78, respectively), whose post RDN values were not significant different from the pre-RDN ones. More than 10 renal nerves ablations were found to be needed for obtaining a significant sympathoinhibition. CONCLUSIONS: This meta-analysis, the first ever done on the MSNA responses to RDN, shows that in a consistent number of RHT patients RDN is associated with a significant, although modest, central sympathoinhibition, which appears to be unrelated to the BP lowering effects of the procedure. Thus factors other than the central sympathetic outflow inhibition may concur at the BP lowering effects of RDN.