Renal denervation prevents subclinical atrial fibrillation in patients with hypertensive heart disease: Randomized, sham-controlled trial

Renal denervation: a key approach to hypertension and cardiovascular disease

Sympathetic activation plays a critical role in the development of hypertension and cardiovascular disease, including heart failure and arrhythmias. Renal nerves contribute to the regulation of blood pressure and fluid volume through renal sympathetic efferent nerves, and to the modulation of sympathetic outflow through renal sensory afferent nerves. Previous studies including ours suggest that selective afferent renal denervation with preservation of efferent renal nerves can significantly decrease central sympathetic outflow in animal models of hypertension with renal damage. In Dahl salt-sensitive rats fed high salt diet from an early age, a model of hypertensive heart failure, this central sympathoinhibition by afferent renal denervation may attenuate the development of heart failure without significant blood pressure reduction. Accumulating clinical evidence supports the efficacy of renal denervation as an antihypertensive treatment. However, it remains important to clarify the appropriate indications and predictors of responders to renal denervation in the treatment of hypertension. Several clinical studies suggest beneficial effects of renal denervation in patients with heart disease, with or without hypertension, although most were not sham-controlled. In particular, some clinical studies have demonstrated that renal denervation reduces the incidence of atrial fibrillation or cardiovascular events even without a significant antihypertensive effect. It is essential to accumulate more insightful data in patients undergoing renal denervation, to establish the efficacy of renal denervation in patients with cardiovascular disease in the clinical setting, and to elucidate the therapeutic mechanisms of renal denervation and the renal nerves-linked pathophysiology of cardiovascular disease in basic research. This review outlines the effects of renal denervation on sympathetic activity and organ damage in animal models of hypertension and hypertensive heart failure, including our own data. Beyond the antihypertensive effects, the beneficial effects of renal denervation on cardiovascular disease are also discussed based on clinical studies. Several animal and clinical studies suggest the cardioprotective effects of renal denervation even in the absence of significant blood pressure reduction, probably due to its sympathoinhibitory effects.

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.

Effects of renal denervation on blood pressure in patients with hypertension: a latest systematic review and meta-analysis of randomized sham-controlled trials

The efficacy of renal denervation (RDN) has been controversial, but recent randomized sham-controlled trials demonstrated significant blood pressure reductions after RDN in patients with hypertension. We conducted a systematic review and updated meta-analysis to evaluate the effects of RDN on ambulatory and office blood pressures in patients with hypertension. Databases were searched up to 15 November 2023 to identify randomized, sham-controlled trials of RDN. The primary endpoint was change in 24 h ambulatory systolic blood pressure (SBP) with RDN versus sham control. The secondary endpoints were changes in 24 h ambulatory diastolic blood pressure, daytime and nighttime blood pressure (BP), office BP, and home BP. A sub-analysis determined outcomes by medication, procedure, and device. From twelve trials, 2222 patients with hypertension were randomized to undergo RDN (n = 1295) or a sham procedure (n = 927). At 2-6 months after treatment, RDN significantly reduced 24 h ambulatory SBP by 2.81 mmHg (95% confidence interval: -4.09, -1.53; p < 0.001) compared with the sham procedure. RDN also reduced daytime SBP by 3.17 mmHg (- 4.75, - 1.58; p < 0.001), nighttime SBP by 3.41 mmHg (- 4.69, - 2.13; p < 0.001), office SBP by 4.95 mmHg (- 6.37, - 3.54; p < 0.001), and home SBP by 4.64 mmHg (- 7.44, - 1.84; p = 0.001) versus the sham control group. There were no significant differences in the magnitude of BP reduction between first- and second-generation trials, between devices, or between with or without medication. These data from randomized sham-controlled trials showed that RDN significantly reduced all blood pressure metrics in medicated or unmedicated patients with hypertension, including resistant/uncontrolled hypertension.

Impact of renal denervation on quality of life (How does renal denervation contribute to improving hypertension treatment affected by poor medication adherence?)

The US Food and Drug Administration has approved renal denervation (RDN) as a new treatment option for hypertension (HT) because it not only has antihypertensive effects but also improves the quality of blood pressure (BP) reduction. RDN is expected to be increasingly used in clinical practice in the future. This review summarizes the impact of RDN on quality of life (QOL). Although the treatment of HT aims to improve life prognosis, the use of antihypertensive agents can impair QOL because of adverse effects and lifestyle changes associated with long-term medication use. Consequently, poor adherence to antihypertensive agents is a common problem and may be the most important issue affecting patient QOL. In RDN trials in patients taking antihypertensive agents, approximately 40% of patients had poor adherence to the drugs. Poor adherence is often the cause of resistant hypertension. Therefore, RDN should be well suited to treating HT and improving QOL. Studies have shown that approximately 30% of HT patients prefer RDN to drug treatment. Patients who prefer RDN are typically male and younger and have high BP, poor adherence, and a history of adverse effects of antihypertensive agents. We hope that RDN will improve not only life prognosis but also QOL in HT patients because of its benefits for adherence. Furthermore, we expect that in the future, RDN will be used in other sympathetic nervous system-related diseases, such as heart failure, atrial fibrillation, and sleep apnea syndrome.

Renal denervation for hypertensive heart disease and atrial fibrillation

Accumulating evidence supports the efficacy of renal denervation (RDN) as an antihypertensive treatment. Additionally, several RDN clinical studies, including meta-analyses, have suggested that RDN may potentially have beneficial effects on left ventricular hypertrophy, diastolic function, and new-onset/recurrence of atrial fibrillation (AF), although most studies were not randomized sham-controlled. In particular, the effects of RDN on left ventricular hypertrophy and AF recurrence appear to be relatively evident. Sympathetic activation plays a critical role in the development of hypertension, hypertensive heart disease, and AF. Notably, several studies suggest the cardioprotective effects of RDN even in the absence of significant blood pressure reduction, probably due to its sympathoinhibitory effects. It is imperative to establish the efficacy of RDN in patients with hypertensive heart disease and/or AF, focusing on parameters of sympathetic activity in the clinical setting, including randomized sham-controlled trials. Moreover, further basic research is essential to elucidate the therapeutic mechanisms of RDN beyond blood pressure lowering and the renal nerves-linked pathophysiologies of hypertensive heart disease and AF. This review outlines the effects of renal denervation on hypertensive heart disease, particularly on left ventricular hypertrophy and diastolic function, and on atrial fibrillation. The sympathoinhibitory effect of renal denervation, an important potential mechanism of its beneficial effects on heart disease, is also discussed.

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.

Long-Term Changes in Atrial Arrhythmia Burden After Renal Denervation Combined With Pulmonary Vein Isolation: SYMPLICITY-AF

BACKGROUND

The autonomic nervous system plays an important role in atrial fibrillation (AF) and hypertension. Renal denervation (RDN) lowers blood pressure (BP), but its role in AF is poorly understood.

OBJECTIVES

The purpose of this study was to investigate whether RDN reduces AF recurrence after pulmonary vein isolation (PVI).

METHODS

This study randomized patients from 8 centers (United States, Germany) with drug-refractory AF for treatment with PVI+RDN vs PVI alone. A multielectrode radiofrequency Spyral catheter system was used for RDN. Insertable cardiac monitors were used for continuous rhythm monitoring. The primary efficacy endpoint was ≥2 minutes of AF recurrence or repeat ablation during all follow-up. The secondary endpoints included atrial arrhythmia (AA) burden, discontinuation of class I/III antiarrhythmic drugs, and BP changes from baseline.

RESULTS

A total of 70 patients with AF (52 paroxysmal, 18 persistent) and uncontrolled hypertension were randomized (RDN+PVI, n = 34; PVI, n = 36). At 3.5 years, 26.2% and 21.4% of patients in RDN+PVI and PVI groups, respectively, were free from the primary efficacy endpoint (log rank P = 0.73). Patients with mean ≥1 h/d AA had less daily AA burden after RDN+PVI vs PVI (4.1 hours vs 9.2 hours; P = 0.016). More patients discontinued class I/III antiarrhythmic drugs after RDN+PVI vs PVI (45% vs 14%; P = 0.040). At 1 year, systolic BP changed by -17.8 ± 12.8 mm Hg and -13.7 ± 18.8 mm Hg after RDN+PVI and PVI, respectively (P = 0.43). The composite safety endpoint was not significantly different between groups.

CONCLUSIONS

In patients with AF and uncontrolled BP, RDN+PVI did not prevent AF recurrence more than PVI alone. However, RDN+PVI may reduce AF burden and antiarrhythmic drug usage, but this needs further prospective validation.

Autonomic neuronal modulations in cardiac arrhythmias: Current concepts and emerging therapies

The pathophysiology of atrial fibrillation and ventricular tachycardia that result in cardiac arrhythmias is related to the sustained complicated mechanisms of the autonomic nervous system. Atrial fibrillation is when the heart beats irregularly, and ventricular arrhythmias are rapid and inconsistent heart rhythms, which involves many factors including the autonomic nervous system. It's a complex topic that requires careful exploration. Cultivation of speculative knowledge on atrial fibrillation; the irregular rhythm of the heart and ventricular arrhythmias; rapid oscillating waves resulting from mistakenly inconsistent P waves, and the inclusion of an autonomic nervous system is an inconceivable approach toward clinical intricacies. Autonomic modulation, therefore, acquires new expansions and conceptions of appealing therapeutic intelligence to prevent cardiac arrhythmia. Notably, autonomic modulation uses the neural tissue's flexibility to cause remodeling and, hence, provide therapeutic effects. In addition, autonomic modulation techniques included stimulation of the vagus nerve and tragus, renal denervation, cardiac sympathetic denervation, and baroreceptor activation treatment. Strong preclinical evidence and early human studies support the annihilation of cardiac arrhythmias by sympathetic and parasympathetic systems to transmigrate the cardiac myocytes and myocardium as efficient determinants at the cellular and physiological levels. However, the goal of this study is to draw attention to these promising early pre-clinical and clinical arrhythmia treatment options that use autonomic modulation as a therapeutic modality to conquer the troublesome process of irregular heart movements. Additionally, we provide a summary of the numerous techniques for measuring autonomic tone such as heart rate oscillations and its association with cutaneous sympathetic nerve activity appear to be substitute indicators and predictors of the outcome of treatment.

The Role of Risk Factor Modification in Atrial Fibrillation: Outcomes in Catheter Ablation

The management of atrial fibrillation has evolved significantly over the last ten years with advancements in medical and catheter ablation approaches, but these have limited success when used in isolation. Trends in the management of lifestyle modifications have surfaced, as it is now better understood that modifiable risk factors contribute significantly to the development and propagation of atrial fibrillation, as well as failure of treatment. International guidelines have integrated the role of lifestyle modification in the management of atrial fibrillation and specifically in the persistent form of atrial fibrillation; these guidelines must be addressed prior to considering catheter ablation. Effective risk factor modification is critical in increasing the likelihood of an arrhythmia-free survival following catheter ablation.

Long-term safety and efficacy of renal sympathetic denervation in atrial fibrillation: 3-year results of the AFFORD study

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia which has been associated with increased sympathetic nervous system activity and hypertension. Recent evidence indicated that renal sympathetic denervation (RDN) could safely contribute to an improvement in AF burden.

OBJECTIVE

To investigate the long-term safety and efficacy of radiofrequency RDN in hypertensive patients with symptomatic AF.

METHODS

This pilot study included patients with symptomatic paroxysmal or persistent AF (European Hearth Rhythm Association class ≥ II) despite optimal medical therapy, office systolic blood pressure (BP) ≥ 140 mmHg and ≥ 2 antihypertensive drugs. AF burden was measured using an implantable cardiac monitor (ICM), implanted 3 months prior to RDN. ICM interrogation and 24-h ambulatory BP monitoring were performed at baseline and at 3/6/12/24/36 months post RDN. The primary efficacy outcome was daily AF burden. Statistical analyses were performed using Poisson and negative binomial models.

RESULTS

A total of 20 patients with a median age [25th-75th percentiles] of 66.2 [61.2-70.8] years (55% female) were included. At baseline, office BP ± standard deviation (SD) was 153.8/87.5 ± 15.2/10.4 mmHg, while mean 24-h ambulatory BP was 129.5/77.3 ± 15.5/9.3 mmHg. Baseline daily AF burden was 1.4 [0.0-10.9] minutes/day and throughout a 3-year follow-up period, no significant change was observed (- 15.4%/year; 95% confidence interval (CI) - 50.2%, + 43.7%; p = 0.54). The number of defined daily doses of antiarrhythmic drugs and antihypertensive drugs remained stable over time, while mean 24-h ambulatory systolic BP decreased with - 2.2 (95% CI - 3.9, - 0.6; p = 0.01) mmHg/year.

CONCLUSIONS

In patients with hypertension and symptomatic AF, stand-alone RDN reduced BP but did not significantly reduce AF burden up until 3 years of follow-up.

Novel laparoscopic renal denervation immediately reduces atrial fibrillation inducibility: a swine model study

Catheter-based approaches may have inherent limitations in achieving effective renal denervation (RDN) and treatment of atrial fibrillation (AF). This study aimed to investigate the acute effects of novel laparoscopic RDN on modulating AF inducibility using a swine model. Four and five swine were randomly allocated to the sham and RDN groups, respectively. Each swine underwent measurement of the atrial effective refractory period (AERP) and AF induction tests using burst atrial pacing before and immediately after sham or RDN procedures with and without vagal nerve stimulation (VNS). A laparoscopic RDN procedure circumferentially ablated the renal nerves round the renal arteries using radiofrequency energy. There was no significant difference in the baseline AERP between the two groups (p > 0.05). Under VNS, AERP was significantly increased by 20 ms after laparoscopic RDN (95% CI = 0-30, p = 0.004). Compared to the sham group, the RDN group showed significantly reduced AF inducibility [OR (95% CI) = 0.32 (0.13-0.76) and 0.24 (0.11-0.57) with and without VNS, respectively]. After laparoscopic RDN, the duration of inducible AF episodes was significantly shortened from 28 (10-77) s to 7 (3-11) s (p < 0.001). The novel laparoscopic RDN can immediately reduce AF inducibility in a swine model.

Long-term reduction in morning and nighttime blood pressure after renal denervation: 36-month results from SPYRAL HTN-ON MED trial

Elevated morning and nighttime blood pressures (BP) are associated with increased risk of cardiovascular events such as stroke and myocardial infarction. We compared the long-term changes in morning and nighttime BP in patients with uncontrolled hypertension (office systolic BP between 150 and <180 mmHg/diastolic BP ≥ 90 mmHg; mean ambulatory systolic BP (SBP) between 140 and <170 mmHg; 1-3 prescribed antihypertensive medications). Eighty patients were randomized to RDN or sham control. In patients taking at least 3 antihypertensive medications at 36 months (N = 23 RDN group; N = 23 sham group), the 24 h ambulatory SBP as well as morning (7:00-9:00AM) and nighttime (1:00-6:00AM) ambulatory SBP were significantly lower for the RDN group compared to sham control (24 h SBP: -20.2 vs. -10.2, p = 0.0087; morning SBP: -23.9 vs. -8.0 mmHg, p = 0.029; nighttime SBP: -20.8 vs. -7.2 mmHg, p = 0.0011). At 36 months, 24 h SBP was controlled to <130 mmHg in 40% of RDN patients in the morning compared to 6% for the sham group; P = 0.021 and in 80% of the RDN patients at night compared to 39% in the sham group; P = 0.019. Major adverse events through 36 months were rare in both groups, and there were no renal artery re-interventions or vascular complications. Morning and nighttime SBP were significantly lower in patients prescribed at least 3 antihypertensive medications at 36 months in the SPYRAL HTN-ON MED trial for RDN compared with sham control. The results suggest RDN has significant benefit when the risk of cardiovascular events is highest.