Impact of Renal Denervation on Patients With Obstructive Sleep Apnea and Resistant Hypertension - Insights From the SYMPLICITY HTN-3 Trial

What are the ideal metrics for assessing the quality of long-term stabilized "perfect" 24-h BP control after renal denervation?

A significant number of individuals being treated for hypertension still have uncontrolled blood pressure (BP). In Japan, renal denervation (RDN) is being introduced into clinical practice as an adjunctive treatment for hypertension that is uncontrolled despite adequate lifestyle changes and maximal antihypertensive drug therapy. The pivotal SPYRAL ON-MED trial showed that there was a significant reduction in trough office and nighttime ambulatory BP values in the RDN group compared with sham control group, although 24-h and daytime BP values were not significantly different between the two groups. The trough office BP measurement (taken before morning antihypertensive dosing) is similar to guideline recommendations for taking morning home BP before taking the morning antihypertensive drug dose. Recent guidelines recommend the measurement of nighttime BP because nighttime BP is a stronger predictor of cardiovascular event risk than daytime BP. It is particularly important to assess nighttime BP in medicated individuals with hypertension because the up- or down-titration of antihypertensive drug dosing is primarily based on office and daytime BPs in clinical practice. This means that there may be significant risk relating to nocturnal hypertension during longer follow-up. Because RDN results in persistent, "always-on" 24-h BP-lowering effects, the best BP metrics to assess the potential benefit of RDN are nighttime BP (determined using home or ambulatory BP monitoring) and morning BP (determined using home BP monitoring or morning trough office BP measurement). The variability of office, home, and ambulatory BP values is another important metric to assess the quality of RDN-related BP lowering.

Consensus Statement on Renal Denervation by the Joint Committee of Japanese Society of Hypertension (JSH), Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT), and the Japanese Circulation Society (JCS)

This is the first consensus statement of the Joint Committee on Renal Denervation of the Japanese Society of Hypertension (JSH)/Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT)/Japanese Circulation Society (JCS). The consensus is that the indication for renal denervation (RDN) is resistant hypertension or "conditioned" uncontrolled hypertension, with high office and out-of-office blood pressure (BP) readings despite appropriate lifestyle modification and antihypertensive drug therapy. "Conditioned" uncontrolled hypertension is defined as having one of the following: 1) inability to up-titrate antihypertensive medication due to side effects, the presence of complications, or reduced quality of life. This includes patients who are intolerant of antihypertensive drugs; or 2) comorbidity at high cardiovascular risk due to increased sympathetic nerve activity, such as orthostatic hypertension, morning hypertension, nocturnal hypertension, or sleep apnea (unable to use continuous positive airway pressure), atrial fibrillation, ventricular arrythmia, or heart failure. RDN should be performed by the multidisciplinary Hypertension Renal Denervation Treatment (HRT) team, led by specialists in hypertension, cardiovascular intervention and cardiology, in specialized centers validated by JSH, CVIT, and JCS. The HRT team reviews lifestyle modifications and medication, and the patient profile, then determines the presence of an indication of RDN based on shared decision making with each patient. Once approval for real-world clinical use in Japan, however, the joint RDN committee will update the indication and treatment implementation guidance as appropriate (annually if necessary) based on future real-world evidence.

Consensus statement on renal denervation by the Joint Committee of Japanese Society of Hypertension (JSH), Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT), and the Japanese Circulation Society (JCS)

This is the first consensus statement of the Joint Committee on Renal Denervation of the Japanese Society of Hypertension (JSH)/Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT)/Japanese Circulation Society (JCS). The consensus is that the indication for renal denervation (RDN) is resistant hypertension or "conditioned" uncontrolled hypertension, with high office and out-of-office blood pressure (BP) readings despite appropriate lifestyle modification and antihypertensive drug therapy. "Conditioned" uncontrolled hypertension is defined as having one of the following: (1) inability to up-titrate antihypertensive medication due to side effects, the presence of complications, or reduced quality of life. This includes patients who are intolerant of antihypertensive drugs; or (2) comorbidity at high cardiovascular risk due to increased sympathetic nerve activity, such as orthostatic hypertension, morning hypertension, nocturnal hypertension, or sleep apnea (unable to use continuous positive airway pressure), atrial fibrillation, ventricular arrythmia, or heart failure. RDN should be performed by the multidisciplinary Hypertension Renal Denervation Treatment (HRT) team, led by specialists in hypertension, cardiovascular intervention and cardiology, in specialized centers validated by JSH, CVIT, and JCS. The HRT team reviews lifestyle modifications and medication, and the patient profile, then determines the presence of an indication of RDN based on shared decision making with each patient. Once approval for real-world clinical use in Japan, however, the joint RDN committee will update the indication and treatment implementation guidance as appropriate (annually if necessary) based on future real-world evidence.

Patient-Specific Factors Predicting Renal Denervation Response in Patients With Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

The accurate selection of patients likely to respond to renal denervation (RDN) is crucial for optimizing treatment outcomes in patients with hypertension. This systematic review was designed to evaluate patient-specific factors predicting the RDN response.

METHODS AND RESULTS

We focused on individuals with hypertension who underwent RDN. Patients were categorized based on their baseline characteristics. The primary outcome was blood pressure (BP) reduction after RDN. Both randomized controlled trials and nonrandomized studies were included. We assessed the risk of bias using corresponding tools and further employed the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the overall quality of evidence. A total of 50 studies were ultimately included in this systematic review, among which 17 studies were for meta-analysis. Higher baseline heart rate and lower pulse wave velocity were shown to be associated with significant antihypertensive efficacy of RDN on 24-hour systolic BP reduction (weighted mean difference, -4.05 [95% CI, -7.33 to -0.77]; weighted mean difference, -7.20 [95% CI, -9.79 to -4.62], respectively). In addition, based on qualitative analysis, higher baseline BP, orthostatic hypertension, impaired baroreflex sensitivity, and several biomarkers are also reported to be associated with significant BP reduction after RDN.

CONCLUSIONS

In patients with hypertension treated with the RDN, higher heart rate, and lower pulse wave velocity were associated with significant BP reduction after RDN. Other factors, including higher baseline BP, hypertensive patients with orthostatic hypertension, BP variability, impaired cardiac baroreflex sensitivity, and some biomarkers are also reported to be associated with a better BP response to RDN.

Renal Denervation in the Treatment of Resistant Hypertension and Difficult-to-Control Hypertension - Consensus Document of the Croatian Hypertension League - Croatian Society of Hypertension, Croatian Cardiac Society, Croatian Endovascular Initiative, Croatian Society for Diabetes and Metabolic Diseases, Croatian Renal Association, and Croatian Society of Family Physicians of the Croatian Medical Association

Renal denervation (RDN) as a method of treating arterial hypertension (AH) was introduced in Croatia in 2012. A multidisciplinary team and a network of hospitals that diagnose and treat patients with severe forms of AH were established, and a very strict diagnostic-treatment algorithm was prepared. At monthly meetings patients with truly resistant hypertension who were candidates for RDN were discussed. According to the 2021 ESH position statement and 2023 ESH guidelines, RDN is considered an alternative and additional, not a competitive method of treating patients with various forms of AH which must be performed by following a structured procedure and the patient's preference should be considered. In view of the changes in the global scientific community, the Croatian Hypertension League brings this consensus document on RDN conducted with radiofrequency-based catheter, the only currently available method in Croatia. In this document, exclusion and inclusion criteria are shown, as well as three groups of patients in whom RDN could be considered. The new diagnostic-treatment algorithm is prepared and follow-up procedure is explained. In Croatia, RDN is reimbursed by the national insurance company, thus pharmacoeconomic analyses is also shown. Criteria required by an individual centre to be approved of RDN are listed, and plans for prospective research on RDN in Croatia, including the Croatian registry for RDN, are discussed.

Progression of obstructive sleep apnoea after renal denervation is not associated with hypertension exaggeration

PURPOSE

In a cohort, observational prospective trial, we assessed the long-term dynamics of sleep-disordered breathing in patients with resistant hypertension after renal denervation and their association with blood pressure change at remote follow-up.

MATERIALS AND METHODS

Twenty-eight patients with stable hypertension who were recruited for endovascular radiofrequency renal denervation in 2012-2019 and had valid both baseline and follow-up sleep study, were included in the analysis. All patients underwent physical examination, anthropometry, office and ambulatory blood pressure measurements, blood and urine tests, kidney visualization, and full polysomnography before and within 12-36 months after renal denervation.

RESULTS

The average follow-up comprised 30.1 ± 8.4 months. At long-term follow-up, no significant changes in creatinine level, estimated glomerular filtration rate, body mass index were registered. There was a significant increase in sleep apnea severity indices: the mean change in apnea-hypopnea index comprised 9.0(-21.1;25.2) episodes/h, in oxygen desaturation index 6.5(-16.8;35.9) episodes/h, in the average SpO2 -1.7(-5.6;1.9)%. Over 12-month follow-up, there were no significant differences in blood pressure response in patients with and without sleep apnea. The baseline apnea-hypopnea and oxygen desaturation indices and the mean SpO2 were associated with the circadian blood pressure profile at follow-up, but did not correlate with the blood pressure response.

CONCLUSIONS

Although the severity of sleep apnea worsens at > 12 months follow-up after renal denervation, this is not associated with hypertension exaggeration.

Anatomical Basis of Obstructive Sleep Apnoea: A Review of Randomized Controlled Trials

Repeated obstruction and closure of the upper airway, sporadic hypoxic episodes, and sympathetic activity are symptoms of obstructive sleep apnea (OSA). Obstructive sleep apnoea is due to a combination of altered upper airway structure and muscular function, a low arousal threshold and increased loop gain. Although recurrent upper airway (UA) collapse during sleep is the most frequent clinical hallmark of OSA, the exact cause of this collapse is unknown. Furthermore, while continuous positive airway pressure aids in the management of OSA, many patients find it intolerable. As a result, a better knowledge of the causes of OSA may result in more effective treatments. We did a review of randomized controlled trials that were done in this regard in the last 10 years and whose full-text version is available on the PubMed database. A total of 20 articles were finalized for review after applying our criteria. The articles have proposed different theories regarding the anatomical basis responsible for obstructive sleep apnoea. The theories proposed by different studies in the last decade include reduced genioglossus and hypoglossal nerve activity, the pharyngeal muscles' failure to keep the airway open or tighten it, tonsils and adenoid hypertrophy, an oversensitive ventilatory control system and low respiratory arousal threshold, mandibular position, pharyngeal muscles' high sympathetic drive, cephalometric alterations such as mandibular and hyoid bone position and the length of the soft palate, obesity, and neck fat and fluid re-distribution in the body, from the lower to the upper parts while reclining. Given the diverse etiological characteristics of OSA patients and to increase our knowledge of the condition, additional study into this group is required. Filling any knowledge gaps that may exist in the anatomical basis of the onset of OSA is the main objective of this review paper.

Controversies in Hypertension IV: Renal Denervation

Renal denervation is not a cure for hypertension. Although more recent sham-controlled trials were positive, a significant minority of patients in each trial were unresponsive. The optimal patient or patients need to be defined. Combined systolic/diastolic hypertension appears more responsive than isolated systolic hypertension. It remains uncertain whether patients with comorbidities associated with higher adrenergic tone should be targeted, including obesity, diabetes, sleep apnea, and chronic kidney disease. No biomarker can adequately predict response. A key to a successful response is the adequacy of denervation, which currently cannot be assessed in real time. It is uncertain what is the optimal denervation methodology: radiofrequency, ultrasound, or ethanol injection. Radiofrequency requires targeting the distal main renal artery plus major branches and accessory arteries. Although denervation appears to be safe, conclusive data on quality of life, improved target organ damage, and reduced cardiovascular events/mortality are required before denervation can be generally recommended.

Renal Denervation as a Complementary Treatment Option for Uncontrolled Arterial Hypertension: A Situation Assessment

Uncontrolled arterial hypertension is a major global health issue. Catheter-based renal denervation has shown to lower blood pressure in sham-controlled trials and represents a device-based, complementary treatment option for hypertension. In this situation assessment, the authors, who are practicing experts in hypertension, nephrology, general practice and cardiology in the Republic of Ireland, discuss the current evidence base for the BP-lowering efficacy and safety of catheter-based renal denervation with different modalities. Although important questions remain regarding the identification of responders, and long-term efficacy and safety of the intervention, renal denervation has the potential to provide much-needed help to address hypertension and its adverse consequences. The therapeutic approach needs to be multidisciplinary and personalised to take into account the perspective of patients and healthcare professionals in a shared decision-making process.

2022 Renal denervation therapy for the treatment of hypertension: a statement from the Thai Hypertension Society

Hypertension remains a significant risk factor for major cardiovascular events worldwide. Poor adherence to treatment is extremely common in clinical practice, leading to uncontrolled hypertension. However, some patients with resistant hypertension still have uncontrolled blood pressure despite good medical compliance. A specific group of patients also develop adverse reactions to many blood pressure-lowering medications. These scenarios indicate that innovative strategies to lower blood pressure in challenging cases of hypertension are needed. The blood pressure-lowering efficacy of catheter-based renal denervation therapy to decrease sympathetic tone has been confirmed in many publications in recent years. Apart from both the invasiveness and the expensiveness of this technology, appropriate case selection to undergo this procedure is still developing. The utilization of renal denervation therapy for hypertension treatment in Thailand has lasted for 10 years with a good response in most cases. Currently, only certain interventionists at a few medical schools in Thailand can perform this procedure. However, more physicians are now interested in applying this technology to their patients. The Thai Hypertension Society Committee has reviewed updated information to provide principles for the appropriate utilization of renal denervation therapy. The blood pressure-lowering mechanism, efficacy, suitable patient selection, pre- and postprocedural assessment and procedural safety of renal denervation are included in this statement.

Long-term outcomes after catheter-based renal artery denervation for resistant hypertension: final follow-up of the randomised SYMPLICITY HTN-3 Trial

BACKGROUND

The SYMPLICITY HTN-3 (Renal Denervation in Patients With Uncontrolled Hypertension) trial showed the safety but not efficacy of the Symplicity system (Medtronic, Santa Rosa, CA, USA) at 6 months follow-up in patients with treatment-resistant hypertension. This final report presents the 36-month follow-up results.

METHODS

SYMPLICITY HTN-3 was a single-blind, multicentre, sham-controlled, randomised clinical trial, done in 88 centres in the USA. Adults aged 18-80 years, with treatment-resistant hypertension on stable, maximally tolerated doses of three or more drugs including a diuretic, who had a seated office systolic blood pressure of 160 mm Hg or more and 24 h ambulatory systolic blood pressure of 135 mm Hg or more were randomly assigned (2:1) to receive renal artery denervation using the single electrode (Flex) catheter or a sham control. The original primary endpoint was the change in office systolic blood pressure from baseline to 6 months for the renal artery denervation group compared with the sham control group. Patients were unmasked after the primary endpoint assessment at 6 months, at which point eligible patients in the sham control group who met the inclusion criteria (office blood pressure ≥160 mm Hg, 24 h ambulatory systolic blood pressure ≥135 mm Hg, and still prescribed three or more antihypertensive medications) could cross over to receive renal artery denervation. Changes in blood pressure up to 36 months were analysed in patients in the original renal artery denervation group and sham control group, including those who underwent renal artery denervation after 6 months (crossover group) and those who did not (non-crossover group). For comparisons between the renal artery denervation and sham control groups, follow-up blood pressure values were imputed for patients in the crossover group using their most recent pre-crossover masked blood pressure value. We report long-term blood pressure changes in renal artery denervation and sham control groups, and investigate blood pressure control in both groups using time in therapeutic blood pressure range analysis. The primary safety endpoint was the incidence of all-cause mortality, end stage renal disease, significant embolic event, renal artery perforation or dissection requiring intervention, vascular complications, hospitalisation for hypertensive crisis unrelated to non-adherence to medications, or new renal artery stenosis of more than 70% within 6 months. The trial is registered with ClinicalTrials.gov, NCT01418261.

FINDINGS

From Sep 29, 2011, to May 6, 2013, 1442 patients were screened, of whom 535 (37%; 210 [39%] women and 325 [61%] men; mean age 57·9 years [SD 10·7]) were randomly assigned: 364 (68%) patients received renal artery denervation (mean age 57·9 years [10·4]) and 171 (32%) received the sham control (mean age 56·2 years [11·2]). 36-month follow-up data were available for 219 patients (original renal artery denervation group), 63 patients (crossover group), and 33 patients (non-crossover group). At 36 months, the change in office systolic blood pressure was -26·4 mm Hg (SD 25·9) in the renal artery denervation group and -5·7 mm Hg (24·4) in the sham control group (adjusted treatment difference -22·1 mm Hg [95% CI -27·2 to -17·0]; p≤0·0001). The change in 24 h ambulatory systolic blood pressure at 36 months was -15·6 mm Hg (SD 20·8) in the renal artery denervation group and -0·3 mm Hg (15·1) in the sham control group (adjusted treatment difference -16·5 mm Hg [95% CI -20·5 to -12·5]; p≤0·0001). Without imputation, the renal artery denervation group spent a significantly longer time in therapeutic blood pressure range (ie, better blood pressure control) than patients in the sham control group (18% [SD 25·0] for the renal artery denervation group vs 9% [SD 18·8] for the sham control group; p≤0·0001) despite a similar medication burden, with consistent and significant results with imputation. Rates of adverse events were similar across treatment groups, with no evidence of late-emerging complications from renal artery denervation. The rate of the composite safety endpoint to 48 months, including all-cause death, new-onset end-stage renal disease, significant embolic event resulting in end-organ damage, vascular complication, renal artery re-intervention, and hypertensive emergency was 15% (54 of 352 patients) for the renal artery denervation group, 14% (13 of 96 patients) for the crossover group, and 14% (10 of 69 patients) for the non-crossover group.

INTERPRETATION

This final report of the SYMPLICITY HTN-3 trial adds to the totality of evidence supporting the safety of renal artery denervation to 36 months after the procedure. From 12 months to 36 months after the procedure, patients who were originally randomly assigned to receive renal artery denervation had larger reductions in blood pressure and better blood pressure control compared with patients who received sham control.

FUNDING

Medtronic.

Renal Denervation: A Review

Uncontrolled hypertension persists as an important health issue despite the availability of many medications and nondrug therapies that lower blood pressure. Increasingly, nonadherence to medication is found in approximately 2 of every 5 patients with uncontrolled hypertension. In the search for interventions that lower blood pressure that do not rely on adherence to a regimen requiring daily ingestion of medication or repeated physical activity, device-based methods that denervate the renal arteries have emerged as a potential complement to standard antihypertensive treatments. At least 3 different approaches to renal artery denervation are under active investigation, including the use of radiofrequency energy, ultrasound, or the injection of neurolytic agents into the renal perivascular tissue. In this review, we cover what is currently known about the mechanisms of antihypertensive effects of renal denervation, summarize the efficacy and safety of renal denervation using recent controlled trial publications in a number of hypertensive populations, and conclude with some thoughts about challenges in the field, including the optimization of patient selection for the procedure and what the reader can expect in the near future in this rapidly developing field.

Renal denervation in the antihypertensive arsenal - knowns and known unknowns

Even though it has been more than a decade since renal denervation (RDN) was first used to treat hypertension and an intense effort on researching this therapy has been made, it is still not clear how RDN fits into the antihypertensive arsenal. There is no question that RDN lowers blood pressure (BP), it does so to an extent at best corresponding to one antihypertensive drug. The procedure has an excellent safety record. However, it remains clinically impossible to predict whose BP responds to RDN and whose does not. Long-term efficacy data on BP reduction are still unconvincing despite the recent results in the SPYRAL HTN-ON MED trial; experimental studies indicate that reinnervation is occurring after RDN. Although BP is an acceptable surrogate endpoint, there is complete lack of outcome data with RDN. Clear indications for RDN are lacking although patients with resistant hypertension, those with documented increase in activity of the sympathetic system and perhaps those who desire to take fewest medication may be considered.

Effect of different treatments for obstructive sleep apnoea on blood pressure

OBJECTIVE

Obstructive sleep apnoea (OSA) is a common cause of secondary hypertension. This network meta-analysis (NMA) assessed the effect of different OSA treatments on lowering blood pressure.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for relevant randomized controlled trials. The search strategies included the concepts of OSA, blood pressure, hypertension, and blood pressure-reducing treatments without language or data restriction (from inception to 1 June 2021). The outcomes included office SBP, office DBP, daytime SBP (dSBP) and DBP (dDBP), and night-time SBP (nSBP) and DBP (nDBP). A Bayesian network meta-analysis was performed, and mean differences with 95% credibility intervals were calculated.

RESULTS

We reviewed 49 randomized controlled trials involving 4893 patients and the following interventions: continuous positive-airway pressure (CPAP), mandibular advancement devices, nocturnal supplemental oxygen, surgery, β-blocker, angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs), renal sympathetic denervation (RDN), mineralocorticoid receptor antagonists (MRAs), calcium channel blockers. MRAs were significantly associated with blood pressure reduction followed by ACEI/ARB. RDN could reduce office SBP, office DBP, 24-h SBP, 24-h DBP, dSBP, and dDBP. CPAP also demonstrated modest blood pressure lowering.

CONCLUSION

MRAs and ACEIs/ARBs can reduce blood pressure effectively in patients with OSA. RDN is a novel hypertension treatment that lowered blood pressure in such patients. CPAP was associated with mild but stable blood pressure reduction, and it might be helpful as an adjunctive therapy in OSA patients with hypertension.

REVIEW REGISTRATION

This systematic review and meta-analysis was registered in PROSPERO: CRD42021240891.

Nocturnal Hypertension and Heart Failure: Mechanisms, Evidence, and New Treatments

Heart failure (HF) is a common condition with an increasing prevalence. Despite a variety of evidence-based treatments for patients with HF with reduced ejection fraction, morbidity and mortality rates remain high. Furthermore, there are currently no treatments that have yet been shown to reduce complication and death rates in patients who have HF with preserved ejection fraction. Hypertension is a common comorbidity in patients with HF, contributing to disease development and prognosis. For example, hypertension is closely associated with the development of left ventricular hypertrophy, which an important precursor of HF. In particular, nighttime blood pressure (BP) appears to be an important, modifiable risk factor. Both nighttime BP and an abnormal circadian pattern of nighttime BP dipping have been shown to predict development of HF and the occurrence of cardiovascular events, independent of office BP. Key mechanisms for this association include sodium handling/salt sensitivity and increased sympathetic activation. These pathogenic mechanisms are targeted by several new treatment options, including sodium-glucose cotransporter 2 inhibitors, angiotensin receptor neprilysin inhibitors, mineralocorticoid receptor antagonists, and renal denervation. All of these could form part of antihypertensive strategies designed to control nighttime BP and contribute to the goal of achieving perfect 24-hour BP management. Nevertheless, additional research is needed to determine the effects of reducing nighttime BP and improving the circadian BP profile on the rate of HF, other cardiovascular events, and mortality.

Obstructive Sleep Apnea-Induced Neurogenic Nocturnal Hypertension: A Potential Role of Renal Denervation?

There is a bidirectional, causal relationship between obstructive sleep apnea (OSA) and hypertension. OSA-related hypertension is characterized by high rates of masked hypertension, elevated nighttime blood pressure, a nondipper pattern of nocturnal hypertension, and abnormal blood pressure variability. Hypoxia/hypercapnia-related sympathetic activation is a key pathophysiological mechanism linking the 2 conditions. Intermittent hypoxia also stimulates the renin-angiotensin-aldosterone system to promote hypertension development. The negative and additive cardiovascular effects of OSA and hypertension highlight the importance of effectively managing these conditions, especially when they coexist in the same patient. Continuous positive airway pressure is the gold standard therapy for OSA but its effects on blood pressure are relatively modest. Furthermore, this treatment did not reduce the cardiovascular event rate in nonsleepy patients with OSA in randomized controlled trials. Antihypertensive agents targeting sympathetic pathways or the renin-angiotensin-aldosterone system have theoretical potential in comorbid hypertension and OSA, but current evidence is limited and combination strategies are often required in drug resistant or refractory patients. The key role of sympathetic nervous system activation in the development of hypertension in OSA suggests potential for catheter-based renal sympathetic denervation. Although long-term, randomized controlled trials are needed, available data indicate sustained and relevant reductions in blood pressure in patients with hypertension and OSA after renal denervation, with the potential to also improve respiratory parameters. The combination of lifestyle interventions, optimal pharmacological therapy, continuous positive airway pressure therapy, and perhaps also renal denervation might improve cardiovascular risk in patients with OSA.

Chronic intermittent hypoxia impairs diuretic and natriuretic responses to volume expansion in rats with preserved low-pressure baroreflex control of the kidney

We examined the effects of exposure to chronic intermittent hypoxia (CIH) on baroreflex control of renal sympathetic nerve activity (RSNA) and renal excretory responses to volume expansion (VE) before and after intrarenal transient receptor potential vanilloid 1 (TRPV1) blockade by capsaizepine (CPZ). Male Wistar rats were exposed to 96 cycles of hypoxia per day for 14 days (CIH) or normoxia. Urine flow and absolute Na+ excretion during VE were less in CIH-exposed rats, but the progressive decrease in RSNA during VE was preserved. Assessment of the high-pressure baroreflex revealed an increase in the operating and response range of RSNA and decreased slope in CIH-exposed rats with substantial hypertension [+19 mmHg basal mean arterial pressure (MAP)] but not in a second cohort with modest hypertension (+12 mmHg). Intrarenal CPZ caused diuresis, natriuresis, and a reduction in MAP in sham-exposed (sham) and CIH-exposed rats. After intrarenal CPZ, diuretic and natriuretic responses to VE in CIH-exposed rats were equivalent to those of sham rats. TRPV1 expression in the renal pelvic wall was similar in both experimental groups. Exposure to CIH did not elicit glomerular hypertrophy, renal inflammation, or oxidative stress. We conclude that exposure to CIH 1) does not impair the low-pressure baroreflex control of RSNA; 2) has modest effects on the high-pressure baroreflex control of RSNA, most likely indirectly due to hypertension; 3) can elicit hypertension in the absence of kidney injury; and 4) impairs diuretic and natriuretic responses to fluid overload. Our results suggest that exposure to CIH causes renal dysfunction, which may be relevant to obstructive sleep apnea.

Isolated Nocturnal Hypertension: What Do We Know and What Can We Do?

Nocturnal hypertension has been recognized as a significant risk factor for cardio- and cerebrovascular diseases. Blood pressure (BP) monitoring significantly increased our awareness of nocturnal hypertension and studies revealed its influence on target organ damage. Nocturnal hypertension is associated with nonphysiological 24-h BP patterns, which consider inadequate drop or even increment of nighttime BP in comparison with daytime BP (nondipping and reverse dipping). Nevertheless, investigations showed that nocturnal hypertension was a predictor of adverse outcome independently of circadian BP pattern. There are still many uncertainties regarding diagnosis, mechanisms and treatment of nocturnal hypertension. There is a small difference between American and European guidelines in cutoff values defining nocturnal hypertension. Pathophysiology is also not clear because many conditions such as diabetes, metabolic syndrome, obesity, sleep apnea syndrome, and renal diseases are related to nocturnal hypertension and nonphysiological circadian BP pattern, but mechanisms of nocturnal hypertension still remain speculative. Therapeutic approach is another important issue and chronotherapy provided the best results so far. There are studies which showed that some groups of antihypertensive medications are more effective in regulation of nocturnal BP, but it seems that the timing of drug administration has a crucial role in the reduction of nighttime BP and conversion of circadian patterns from nonphysiologic to physiologic. Follow-up studies are necessary to define clinical benefits of nocturnal BP reduction and restoring unfavorable 24-h BP variations to physiological variant.

The relationship of hypertension with obesity and obstructive sleep apnea in adolescents

OBJECTIVES

To assess the independent relationships of obesity and obstructive sleep apnea (OSA) with hypertension/elevated blood pressure (EBP) in adolescent patients.

STUDY DESIGN

A retrospective cohort analysis was performed on 501 patients (age 13-21 years) with three separate blood pressure measurements within 6 months of polysomnography. EBP was defined as average systolic blood pressure (SBP) ≤120 mm Hg; obesity as body mass index Z-score ≤1.65; and OSA as obstructive apnea-hypopnea index <1. Pearson correlations and multivariable analyses were performed to assess the independent effects of the apnea-hypopnea index and body mass index Z-score on SBP.

RESULTS

Of 501 patients (mean age 16 ± 2 years), 246 (49%) were male. OSA was present in 329 (66%) patients, obesity in 337 (67%), and EBP in 262 (52%). EBP was present in 70% of obese adolescents and 60% of adolescents with OSA. Univariable correlation showed a significant relationship between SBP, body mass index Z-score, and apnea-hypopnea index. Multivariable linear regression analysis showed blood pressure was significantly associated with body mass index Z-score (β = .46; P < .01), age (β = .25; P < .01), and height Z-score (β = .14; P < .01), but not apnea-hypopnea index (β = .01; P = .72).

CONCLUSIONS

The relationship between OSA and EBP in adolescents is most closely associated with the degree of obesity. Further studies are needed to assess the effect of the treatment of obesity and OSA on blood pressure in adolescents.

Renal Denervation in Asia: Consensus Statement of the Asia Renal Denervation Consortium

The Asia Renal Denervation Consortium consensus conference of Asian physicians actively performing renal denervation (RDN) was recently convened to share up-to-date information and regional perspectives, with the goal of consensus on RDN in Asia. First- and second-generation trials of RDN have demonstrated the efficacy and safety of this treatment modality for lowering blood pressure in patients with resistant hypertension. Considering the ethnic differences of the hypertension profile and demographics of cardiovascular disease demonstrated in the SYMPLICITY HTN (Renal Denervation in Patients With Uncontrolled Hypertension)-Japan study and Global SYMPLICITY registry data from Korea and Taiwan, RDN might be an effective hypertension management strategy in Asia. Patient preference for device-based therapy should be considered as part of a shared patient-physician decision process. A practical population for RDN treatment could consist of Asian patients with uncontrolled essential hypertension, including resistant hypertension. Opportunities to refine the procedure, expand the therapy to other sympathetically mediated diseases, and explore the specific effects on nocturnal and morning hypertension offer a promising future for RDN. Based on available evidence, RDN should not be considered a therapy of last resort but as an initial therapy option that may be applied alone or as a complementary therapy to antihypertensive medication.

Atrial fibrillation in obstructive sleep apnea: Neural mechanisms and emerging therapies

Obstructive sleep apnea (OSA) has been reproducibly identified as a risk factor for initiation and progression of atrial fibrillation (AF) and reduces the efficacy of antiarrhythmic drugs, electrical cardioversion, and catheter ablation in AF. It is still controversial whether continuous positive airway pressure ventilation (CPAP) could improve the successful rate of AF treatment in OSA patients. Besides, CPAP has shown relative low compliance in patients with OSA. Therefore, novel optional therapies might be needed to improve the control of AF associated with OSA. A growing body of evidence suggests that autonomic activation contributes to the pathogenesis of AF in OSA. Acute apneic episodes result in sympathovagal co-activation, shortening atrial refractoriness and promoting the initiation of AF. Chronic OSA-induced sympathetic activation plays a crucial role in atrial autonomic, structural, and electrical remodeling, thus providing substrates for AF maintenance and recurrence. Therefore, the autonomic nervous system may be a promising therapeutic target for OSA and AF. Autonomic modulation as a treatment for OSA-associated AF has been well established in several preclinical studies. Further clinical studies are needed to provide a more precise definition of the role of autonomic modulation in the treatment of AF in OSA.

Novel Biomarkers of Early Atherosclerotic Changes for Personalised Prevention of Cardiovascular Disease in Cervical Cancer and Human Papillomavirus Infection

Cervical cancer is associated with a causative role of human papillomavirus (HPV), which is a highly prevalent infection. Recently, women with a genital HPV infection were found to have increased incidence of cardiovascular diseases (CVD), including severe cardiovascular events such as myocardial infarction and stroke. The pathomechanisms of this relation are not yet fully understood, and may significantly affect the health of a large part of the population. Accelerated atherosclerosis is assumed to play a key role in the pathophysiology of this relationship. To identify high-risk groups of the population, it is necessary to stratify the CVD risk. Current algorithms, as widely used for the estimation of CVD risk, seem to be limited by the individual misclassification of high-risk subjects. However, personalised prediction of cardiovascular events is missing. Regarding HPV-related CVD, identification of novel sensitive biomarkers reflecting early atherosclerotic changes could be of major importance for such personalised cardiovascular risk prediction. Therefore, this review focuses on the pathomechanisms leading to HPV-related cardiovascular diseases with respect to atherosclerosis, and the description of potential novel biomarkers to detect the earliest atherosclerotic changes important for the prevention of CVD in HPV infection and cervical cancer.

Resistant Hypertension: Detection, Evaluation, and Management: A Scientific Statement From the American Heart Association

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

Proximal Tubule-Specific Deletion of the NHE3 (Na+/H+ Exchanger 3) Promotes the Pressure-Natriuresis Response and Lowers Blood Pressure in Mice

The present study directly tested the hypothesis that deletion of the NHE3 (Na⁺/H⁺ exchanger 3) selectively in the proximal tubules of the kidney lowers basal blood pressure by increasing the pressure-natriuresis response in mice. Adult male and female, age-matched wild-type (WT) littermates and proximal tubule-specific NHE3 knockout mice (PT- Nhe3^-/-; n=6-16 per group) were studied for (1) basal phenotypes of electrolytes and pH, blood pressure, and kidney function; (2) the pressure-natriuresis response using the mesenteric, celiac, and abdominal arterial occlusion technique; and (3) the natriuretic responses to acute saline expansion (0.9% NaCl, 10% body weight, intraperitoneal) or 2-week of 2% NaCl diet. Under basal conditions, PT- Nhe3^-/- mice showed significantly lower systolic, diastolic, and mean arterial blood pressure ( P<0.01) than WT mice ( P<0.01). PT- Nhe3^-/- mice also exhibited significantly greater diuretic ( P<0.01) and natriuretic responses than WT mice ( P<0.01), without altering 24-hour fecal Na⁺ excretion, plasma pH, Na⁺, and bicarbonate levels. In response to increased renal perfusion pressure by 30 mm Hg, the pressure-natriuresis response increased 5-fold in WT mice ( P<0.01), but it increased 8-fold in PT- Nhe3^-/- mice ( P<0.01). In response to 10% acute saline expansion or 2-week 2% NaCl diet, more pronounced natriuretic responses were demonstrated in PT- Nhe3^-/- than WT mice ( P<0.01). Our results support the scientific premise and physiological relevance that NHE3 in the proximal tubules plays an essential role in maintaining basal blood pressure homeostasis, and genetic deletion of NHE3 selectively in the proximal tubules of the kidney lowers blood pressure by increasing the pressure natriuretic response.

Is Aberrant Reno-Renal Reflex Control of Blood Pressure a Contributor to Chronic Intermittent Hypoxia-Induced Hypertension?

Renal sensory nerves are important in the regulation of body fluid and electrolyte homeostasis, and blood pressure. Activation of renal mechanoreceptor afferents triggers a negative feedback reno-renal reflex that leads to the inhibition of sympathetic nervous outflow. Conversely, activation of renal chemoreceptor afferents elicits reflex sympathoexcitation. Dysregulation of reno-renal reflexes by suppression of the inhibitory reflex and/or activation of the excitatory reflex impairs blood pressure control, predisposing to hypertension. Obstructive sleep apnoea syndrome (OSAS) is causally related to hypertension. Renal denervation in patients with OSAS or in experimental models of chronic intermittent hypoxia (CIH), a cardinal feature of OSAS due to recurrent apnoeas (pauses in breathing), results in a decrease in circulating norepinephrine levels and attenuation of hypertension. The mechanism of the beneficial effect of renal denervation on blood pressure control in models of CIH and OSAS is not fully understood, since renal denervation interrupts renal afferent signaling to the brain and sympathetic efferent signals to the kidneys. Herein, we consider the currently proposed mechanisms involved in the development of hypertension in CIH disease models with a focus on oxidative and inflammatory mediators in the kidneys and their potential influence on renal afferent control of blood pressure, with wider consideration of the evidence available from a variety of hypertension models. We draw focus to the potential contribution of aberrant renal afferent signaling in the development, maintenance and progression of high blood pressure, which may have relevance to CIH-induced hypertension.

Renal Artery Denervation for Hypertension

PURPOSE OF REVIEW

Hypertension (HTN) has a growing impact, already affecting over 1 billion people. An estimated 2-16% of those with HTN have resistant HTN. The sympathetic nervous system (SNS) is a recognized contributor to the pathophysiology of resistant HTN. Current hypertensive pharmacotherapy has not fully targeted the SNS; therefore, the SNS has become a prominent research therapeutic target. This review summarizes the evidence and rationale behind renal denervation (RDN) therapy and the technology available.

RECENT FINDINGS

Prior to the SYMPLICITY HTN-3 clinical trial, trials found RDN to be an effective procedure to control resistant hypertension. The failure of SYMPLICITY HTN-3 to meet its primary efficacy endpoint sparked further studies to address potential shortcomings. The subsequent SPYRAL program trials demonstrated efficacy of RDN therapy in a controlled manner; however, they were not adequately powered. Ongoing research is examining new, innovative RDN technology as well as defining appropriate patients to target for treatment. The data currently available for RDN in HTN and other states of SNS activation suffer from potential biases and limitations, highlighting the need for continued exploration. Contemporary studies are more promising and hypothesis-generating. Future trials and continued device innovation will be crucial for understanding the clinical applications of RDN therapy.

Clinical Significance and Therapeutic Implication of Nocturnal Hypertension: Relationship between Nighttime Blood Pressure and Quality of Sleep

Recent global hypertension guidelines recommend an early, strict and 24-hour blood pressure (BP) control for the prevention of target organ damage and cardiovascular events. Out-of-office BP measurement such as ambulatory BP monitoring and home BP monitoring is now widely utilized to rule out white-coat hypertension, to detect masked hypertension, to evaluate the effects of antihypertensive medication, to analyze diurnal BP variation, and to increase drug adherence. Nocturnal hypertension has been neglected in the management of hypertension despite of its clinical significance. Nighttime BP and non-dipping patterns of BP are stronger risk predictors for the future cardiovascular mortality and morbidity than clinic or daytime BP. In addition to ambulatory or home daytime BP and 24-hour mean BP, nocturnal BP should be a new therapeutic target for the optimal treatment of hypertension to improve prognosis in hypertensive patients. This review will provide an overview of epidemiology, characteristics, and pathophysiology of nocturnal hypertension and clinical significance, therapeutic implication and future perspectives of nocturnal hypertension will be discussed.

Chronic intermittent hypoxia-mediated renal sympathetic nerve activation in hypertension and cardiovascular disease

In sleep apnea syndrome (SAS), chronic intermittent hypoxia (CIH) is believed to activate the sympathetic nerve system, and is thus involved in cardiovascular diseases (CVD). However, since patients with SAS are often already obese, and have diabetes and/or hypertension (HT), the effects of CIH alone on sympathetic nerve activation and its impacts on CVD are largely unknown. We, therefore, examined the effects of CIH on sympathetic nerve activation in non-obese mice to determine whether renal sympathetic nerve denervation (RD) could ameliorate CIH-mediated cardiovascular effects. Male C57BL/6 (WT) mice were exposed to normal (FiO₂ 21%) or CIH (10% O₂, 12 times/h, 8 h/day) conditions for 4 weeks with or without RD treatment. Increased urinary norepinephrine (NE), 8-OHdG, and angiotensinogen levels and elevated serum asymmetric dimethyl arginine levels were observed in the CIH model. Concomitant with these changes, blood pressure levels were significantly elevated by CIH treatment. However, these deleterious effects by CIH were completely blocked by RD treatment. The present study demonstrated that CIH-mediated renal sympathetic nerve activation is involved in increased systemic oxidative stress, endothelial dysfunction, and renin-angiotensin system activation, thereby contributing to the development of HT and CVD, thus could be an important therapeutic target in patients with SAS.

Renal denervation - can we press the "ON" button again?

Nearly ten years ago percutaneous renal denervation (RDN) was introduced in clinical trials as a possible method of interventional treatment of resistant hypertension. The promising results of the first clinical trials initiated the intensive development of this method. However, the role of percutaneous renal denervation in the treatment of patients with resistant hypertension has been questioned since the results of the Symplicity HTN-3 trial have been published. It also resulted in downgrading the indications for RDN in the European Society of Cardiology/European Society of Hypertension Guidelines 2018. The authors discuss potential shortcomings of that trial, describe new generation devices and present the results of recently published trials: SPYRAL HTN-OFF MED, SPYRAL HTN-ON MED, RADIANCE-HTN SOLO and RADIOSOUND-HTN. The results of studies in patients with obstructive sleep apnea are also summarized and discussed. The upcoming large trials (SPYRAL PIVOTAL, RADIANCE II) are outlined - the results of those trials are expected to be published in the next 2-3 years. Until then, according to the European guidelines, the use of device-based therapies is not recommended for the treatment of hypertension, unless in the context of clinical studies and randomized controlled trials.

The Sacubitril/Valsartan, a First-in-Class, Angiotensin Receptor Neprilysin Inhibitor (ARNI): Potential Uses in Hypertension, Heart Failure, and Beyond

PURPOSE OF REVIEW

Sacubitril/valsartan (LCZ696) is a first-in-class, novel-acting, angiotensin receptor neprilysin inhibitor (ARNI) that provides inhibition of neprilysin and the angiotensin (AT₁) receptor. A recent clinical trial PRARDIGM-HF demonstrated that this drug is superior to angiotensin-converting enzyme (ACE) inhibitors for improving the prognosis in the patients with heart failure, and this has resulted in the drug being included in clinical practice guidelines for the management of heart failure with reduced ejection fraction (EF). In addition, sacubitril/valsartan has been developed for the management of hypertension, because it has unique anti-aging properties. However, the clinical evidence of mechanism has not been well validated.

RECENT FINDINGS

A recent mechanistic study PARAMETER demonstrated that sacubitril/valsartan (LCZ696) is superior to angiotensin receptor blocker (ARB) monotherapy for reducing central aortic systolic pressure (primary endpoint) as well as for central aortic pulse pressure (secondary endpoint) and nocturnal BP preferentially. Considering these results, sacubitril/valsartan may be an attractive therapeutic agent to treat the elderly with age-related hypertension phenotypes, such as drug-uncontrolled (resistant) hypertension characterized as systolic (central) hypertension (structural hypertension) and/or nocturnal hypertension (salt-sensitive hypertension). These are the high-risk hypertension phenotypes which are prone to develop heart failure with preserved EF and chronic kidney disease. Sacubitril/valsartan may be effective to suppress the age-related continuum from hypertension to heart failure, and it could be clinically useful not only for secondary prevention, but also as primary prevention of heart failure in uncontrolled elderly hypertensive patients.

Predictive factors for successful renal denervation: should we use them in clinical trials?

Renal denervation (RDN) is facing various challenges to its initial claimed value in hypertension treatment. Major concerns are the choice of the patients and the technical efficacy of the RDN. Different factors have been described as predicting the capacity of RDN to decrease blood pressure. These factors are related to the patients, the procedure and the tools to confirm successful neural ablation. Their use in future trials should help to improve RDN trials understanding and outcomes. This review summarizes the different predictive factors available and their potential benefits in patient selection and in procedure guidance.

[Invasive treatment of hypertension : Update 2016]

Invasive treatment methods-more specifically renal denervation and baroreceptor activator therapy-have been used for the treatment of therapy-resistant hypertension for several years now. In particular, renal denervation has aroused great interest because it was easy to perform and the first studies provided very promising results. Meanwhile, however, three randomized, blinded studies have been published, and none showed a significant benefit of renal denervation compared to a sham procedure. In addition, in several studies it was demonstrated that intensification of drug therapy, particularly with spironolactone, is at least comparable. Carotid sinus node baroreceptor activator therapy tends to be superior to renal denervation, but the probe currently used is not optimal. The first results by inserting an arteriovenous shunt between the iliac artery and vein are promising, but lack long-term safety data. Currently, all invasive treatment procedures should be performed within the framework of studies or accurate register surveys.

Novel Triggered Nocturnal Blood Pressure Monitoring for Sleep Apnea Syndrome: Distribution and Reproducibility of Hypoxia-Triggered Nocturnal Blood Pressure Measurements

Obstructive sleep apnea (OSA) causes blood pressure (BP) surges during sleep, which may lead to increased sleep-onset cardiovascular events. The authors recently developed a triggered nocturnal BP monitoring system that initiates BP measurements when oxygen desaturation falls below a variable threshold. The distribution and reproducibility of hypoxia-triggered nocturnal BP parameters compared with those of fixed-interval nocturnal BP parameters for two consecutive nights in 147 OSA patients (mean age 59.4 years, 86.4% men) were evaluated. The mean and distribution (standard deviation [SD]) of the hypoxia-peak systolic BP (SBP) were significantly greater than that of the mean nocturnal SBP (mean±SD: 148.8±20.5 vs 123.4±14.2 mm Hg, P<.001). The repeatability coefficient (expressed as %MV) of hypoxia-peak SBP between night 1 and night 2 was comparable to that of mean nocturnal SBP (43% vs 32%). In conclusion, hypoxia-peak nocturnal BP was much higher than mean nocturnal BP, and it was as reproducible as mean nocturnal BP.

Effects of renal sympathetic denervation on blood pressure, sleep apnoea severity and metabolic indices: a prospective cohort study

BACKGROUND

Catheter-based renal sympathetic denervation (RSD) significantly reduces blood pressure in patients with resistant hypertension, who commonly have obstructive sleep apnoea (OSA). These patients are considered particularly responsive to the antihypertensive effects of RSD, but additional benefits of metabolic control on sleep apnoea severity have not been thoroughly investigated.

METHODS

The effect of RSD was evaluated prospectively in a cohort of patients with OSA (apnoea-hypopnea index (AHI) ≥15 events per hour and an Epworth Sleepiness Scale (ESS) score ≤9) and treatment resistant hypertension. Changes in blood pressure, polysomnographic parameters and metabolic indices were evaluated at baseline and six months post procedure.

RESULTS

At baseline, mean office blood pressure was 166.3/92.8 (14.5/11.7) mmHg and mean ambulatory blood pressure was 154.0/87.3 (11.9/8.5) mmHg. At six months post RSD, mean office blood pressure reduced by 6.6/6.5 (1.9/2.0) mmHg (p < 0.05) and mean ambulatory blood pressure reduced by 8.3/6.2 (2.3/2.0) (p < 0.05). The mean AHI at baseline was 21.3 events/h and 20.5 events/h at six months post RSD, with a mean reduction of 0.9 events/h (95% CI -0.7-1.6, p = 0.39). Glucose at two hours/2 h following tolerance testing reduced by 1.14 mmol/L (95% CI 0.22-2.06, p = 0.03) but changes in other metabolic indices were not statistically significant.

CONCLUSION

In patients with resistant hypertension and OSA, RSD resulted in modest improvements in blood pressure control, but no significant changes in sleep apnoea severity. Our study showed small increments in glucose tolerance but no significant changes in other markers of carbohydrate or lipid metabolism.

Perfect 24-h management of hypertension: clinical relevance and perspectives

Out-of-office blood pressure (BP) measured by home BP monitoring, or ambulatory BP monitoring, was demonstrated to be superior to office BP for the prediction of cardiovascular events. The J-HOP study of a nationwide Japanese cohort demonstrated that morning home BP is the best stroke predictor. In the prospective HONEST study of >21 000 hypertensives, on-treatment morning home BP was shown to be a strong predictor both of future coronary artery disease and stroke events. In subjects whose office BP was maintained at ⩾150 mm Hg, there was no increase in cardiovascular events when their morning systolic BP was well-controlled at <125 mm Hg. Since Asians show greater morning BP surges, it is particularly important for Asians to achieve 'perfect 24-hr BP control,' that is, the 24-h BP level, nocturnal BP dipping and BP variability including morning surge. The morning BP surge and the extremes of disrupted circadian rhythm (riser and extreme dipper patterns) are independent risks for stroke in hypertensives. A morning BP-guided approach is thus the first step toward perfect 24-h BP control, followed by the control of nocturnal hypertension. In the resonance hypothesis, the synergistic resonance of BP variability phenotypes would produce an extraordinary large 'dynamic BP surge' that can trigger a cardiovascular event, especially in high-risk patients with systemic hemodynamic atherothrombotic syndrome, a vicious cycle of exaggerated BP variability and vascular disease. In the future, information and communications technology and artificial intelligence technology with the innovation of wearable continuous surge BP monitoring will contribute to 'anticipation medicine' with the goal of zero cardiovascular events.

ISN Forefronts Symposium 2015: The Evolution of Hypertension-Old Genes, New Concepts

Hypertension is known as the “silent killer,” driving the global public health burden of cardiovascular and renal disease. Blood pressure homeostasis is intimately associated with sodium balance and the distribution of sodium between fluid compartments and within tissues. On a population level, most societies consume 10 times more salt that the 0.5 g required by physiological need. This high salt intake is strongly linked to hypertension and to the World Health Organization targeting a ∼30% relative reduction in mean population salt intake to arrest the global mortality due to cardiovascular disease. But how does a habitually high-salt diet cause blood pressure to rise? In this focused review, we discuss 2 “evolutionary medicine” concepts, presented at the ISN Forefront Meeting “Immunomodulation of Cardio-renal Function.” We first examine how ancestral variants in genes that conferred a selection advantage during early human development are now maladaptive. We then discuss the conservation of “renal” sodium transport processes across multiple organ systems, including the brain. These systems influence sodium appetite and can exert an often-overlooked effect on long-term blood pressure control.

Systemic Hemodynamic Atherothrombotic Syndrome and Resonance Hypothesis of Blood Pressure Variability: Triggering Cardiovascular Events

Blood pressure (BP) exhibits different variabilities and surges with different time phases, from the shortest beat-by-beat to longest yearly changes. We hypothesized that the synergistic resonance of these BP variabilites generates an extraordinarily large dynamic surge in BP and triggers cardiovascular events (the resonance hypothesis). The power of pulses is transmitted to the peripheral sites without attenuation by the large arteries, in individuals with stiffened arteries. Thus, the effect of a BP surge on cardiovascular risk would be especially exaggerated in high-risk patients with vascular disease. Based on this concept, our group recently proposed a new theory of systemic hemodynamic atherothromboltic syndrome (SHATS), a vicious cycle of hemodynamic stress and vascular disease that advances organ damage and triggers cardiovascular disease. Clinical phenotypes of SHATS are large-artery atherothombotic diseases such as stroke, coronary artery disease, and aortic and pheripheral artery disease; small-artery diseases, and microcirculation-related disease such as vascular cognitive dysfunction, heart failure, and chronic kidney disease. The careful consideration of BP variability and vascular diseases such as SHATS, and the early detection and management of SHATS, will achieve more effective individualized cardiovascular protection. In the near future, information and communication technology-based 'anticipation medicine' predicted by the changes of individual BP values could be a promising approach to achieving zero cardiovascular events.