Catheter-based renal denervation as therapy for chronic severe kidney-related pain.

Background: Loin pain haematuria syndrome (LPHS) and autosomal dominant polycystic kidney disease (ADPKD) are the most important non-urological conditions to cause chronic severe kidney-related pain. Multidisciplinary programmes and surgical methods have shown inconsistent results with respect to pain reduction. Percutaneous catheter-based renal denervation (RDN) could be a less invasive treatment option for these patients. Methods: Our aim was to explore the change in perceived pain and use of analgesic medication from baseline to 3, 6 and 12 months after RDN. Patients with LPHS or ADPKD, who experienced kidney-related pain ≥3 months with a visual analogue scale (VAS) score ≥ 50/100 could be included. Percutaneous RDN was performed with a single-electrode radiofrequency ablation catheter. Results: RDN was performed in 11 patients (6 with LPHS and 5 with ADPKD). Perceived pain declined in the whole group by 23 mm (P = 0.012 for the total group). In patients with LPHS and ADPKD, the median daily defined dosage of analgesic medication decreased from 1.6 [interquartile range (IQR) 0.7-2.3] and 1.4 (IQR 0.0-7.4) at baseline to 0.3 (IQR 0.0-1.9; P = 0.138) and 0.0 (IQR 0.0-0.8; P = 0.285) at 12 months, respectively. Mean estimated glomerular filtration rate decreased in the whole group by 5.4 mL/min/1.73 m2 at 6 months compared with baseline (P = 0.163). Conclusions: These results suggest that percutaneous catheter-based RDN reduces pain complaints and the use of analgesic medication in patients with LPHS or ADPKD. The present results can serve as the rationale for a larger, preferably randomized (sham) controlled study.

Medication adherence in patients with apparent resistant hypertension: findings from the SYMPATHY trial.

AIMS: Hypertension is only controlled in approximately 35% of the patients, which could be partially due to nonadherence. Recently, bioanalytical assessment of adherence to blood pressure (BP) lowering drugs has gaining interest. Our aim was to explore possible determinants of nonadherence in treatment resistant hypertension, assessed by objective screening for antihypertensive agents in serum. The secondary aim was to study the effect of adherence on the change in BP. METHODS: This project was a substudy of SYMPATHY; an open-label randomized-controlled trial to assess the effect of renal denervation on BP 6 months after treatment compared to usual care in patients with resistant hypertension. Stored serum samples were screened for antihypertensive agents to assess adherence at baseline and 6 months after intervention, using liquid chromatography-tandem mass spectrometry. Office and 24-h BP were measured on the same day as blood was sampled. Patients and physicians were unaware of adherence measurements. RESULTS: Ninety-eight baseline and 83 6-month samples were available for analysis. Sixty-eight percent [95% confidence interval (CI) 59-78%] of the patients was nonadherent (n = 67). For every onw pill more prescribed, 0.785 [95%CI 0.529-0.891] prescribed pill was less detected in blood. A decrease of one pill in adherence between baseline and 6 months was associated with a significant rise in office systolic BP of 4 (95%CI 0.230-8.932) mmHg. CONCLUSION: Objective measurement of BP lowering drugs in serum, as a tool to assess adherence, showed that nonadherence was very common in patients with apparent resistant hypertension. Furthermore, the assessment results were related to (changes in) blood pressure. Our findings provide direct and objective methodology to help the physician to understand and to improve the condition of apparent resistant hypertension.

Novel treatment protocol for ameliorating refractory, chronic pain in patients with autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) patients can suffer from chronic pain that can be refractory to conventional treatment, resulting in a wish for nephrectomy. This study aimed to evaluate the effect of a multidisciplinary treatment protocol with sequential nerve blocks on pain relief in ADPKD patients with refractory chronic pain. As a first step a diagnostic, temporary celiac plexus block with local anesthetics was performed. If substantial pain relief was obtained, the assumption was that pain was relayed via the celiac plexus and major splanchnic nerves. When pain recurred, patients were then scheduled for a major splanchnic nerve block with radiofrequency ablation. In cases with no pain relief, it was assumed that pain was relayed via the aortico-renal plexus, and catheter-based renal denervation was performed. Sixty patients were referred, of which 44 were eligible. In 36 patients the diagnostic celiac plexus block resulted in substantial pain relief with a change in the median visual analogue scale (VAS) score pre-post intervention of 50/100. Of these patients, 23 received a major splanchnic nerve block because pain recurred, with a change in median VAS pre-post block of 53/100. In 8 patients without pain relief after the diagnostic block, renal denervation was performed in 5, with a borderline significant change in the median VAS pre-post intervention of 20/100. After a median follow-up of 12 months, 81.8% of the patients experienced a sustained improvement in pain intensity, indicating that our treatment protocol is effective in obtaining pain relief in ADPKD patients with refractory chronic pain.

The effect of renal denervation added to standard pharmacologic treatment versus standard pharmacologic treatment alone in patients with resistant hypertension: rationale and design of the SYMPATHY trial.

The first studies on renal denervation (RDN) suggest that this treatment is feasible, effective, and safe in the short term. Presently available data are promising, but important uncertainties exist; therefore, SYMPATHY has been initiated. SYMPATHY is a multicenter, randomized, controlled trial in patients randomized to RDN in addition to usual care (intervention group) or to continued usual care (control group). Randomization will take place in a ratio of 2 to 1. At least 300 participants will be included to answer the primary objective. Sample size may be extended to a maximum of 570 to address key secondary objectives. The primary objective is to assess whether RDN added to usual care compared with usual care alone reduces blood pressure (BP) (ambulatory daytime systolic BP) in subjects with an average daytime systolic BP ≥135, despite use of ≥3 BP-lowering agents, 6 months after RDN. Key secondary objectives are evaluated at 6 months and at regular intervals during continued follow-up and include the effect of RDN on the use of BP-lowering agents, in different subgroups (across strata of estimated glomerular filtration rate and of baseline BP), on office BP, quality of life, and cost-effectiveness.

Chronic kidney pain in autosomal dominant polycystic kidney disease: a case report of successful treatment by catheter-based renal denervation.

Chronic pain is a common concern in patients with autosomal dominant polycystic kidney disease (ADPKD). We report what to our knowledge is the first catheter-based renal denervation procedure in a patient with ADPKD resulting in successful management of chronic pain. The patient was a 43-year-old woman whose chronic pain could not be controlled by pain medication or splanchnic nerve blockade. Transluminal radiofrequency renal denervation was performed as an experimental therapeutic option with an excellent result, indicating that this procedure should be considered for chronic pain management in ADPKD.

Sympathetic hyperactivity in chronic kidney disease: pathophysiology and (new) treatment options.

Abundant evidence shows that chronic kidney disease (CKD) is a disease state characterized by increased sympathetic activation. Kidney injury (ischemia) plays a central role in this pathogenesis. Sympathetic excitation is associated with an increased risk of cardiovascular morbidity and mortality. Several pharmacologic strategies are developed to decrease sympathetic activity. However, these medications have limitations. Percutaneous catheter-based renal denervation has the potential to become a new treatment option for CKD. This current report focuses on the effects of sympathetic hyperactivity in CKD, and gives an overview in experimental as well as clinical evidence for a central role of the kidneys in the pathophysiology of sympathetic hyperactivity. Moreover, the effect of pharmacologic treatment and the potential beneficial effect of renal denervation will be discussed.

Platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro.

BACKGROUND: In patients with chronic kidney disease studies focusing on platelet function and properties often are non-conclusive whereas only few studies use functional platelet tests. In this study we evaluated a recently developed functional flow cytometry based assay for the analysis of platelet function in chronic kidney disease. METHODS: Platelet reactivity was measured using flow cytometric analysis. Platelets in whole blood were triggered with different concentrations of agonists (TRAP, ADP, CRP). Platelet activation was quantified with staining for P-selectin, measuring the mean fluorescence intensity. Area under the curve and the concentration of half-maximal response were determined. RESULTS: We studied 23 patients with chronic kidney disease (9 patients with cardiorenal failure and 14 patients with end stage renal disease) and 19 healthy controls. Expression of P-selectin on the platelet surface measured as mean fluorescence intensity was significantly less in chronic kidney disease patients compared to controls after maximal stimulation with TRAP (9.7 (7.9-10.8) vs. 11.4 (9.2-12.2), P=0.032), ADP (1.6 (1.2-2.1) vs. 2.6 (1.9-3.5), P=0.002) and CRP (9.2 (8.5-10.8) vs. 11.5 (9.5-12.9), P=0.004). Also the area under the curve was significantly different. There was no significant difference in half-maximal response between both groups. CONCLUSION: In this study we found that patients with chronic kidney disease show reduced platelet reactivity in response of ADP, TRAP and CRP compared to controls. These results contribute to our understanding of the aberrant platelet function observed in patients with chronic kidney disease and emphasize the significance of using functional whole blood platelet activation assays.

Salt intake and blood pressure response to percutaneous renal denervation in resistant hypertension.

The effect of lowering sympathetic nerve activity by renal denervation (RDN) is highly variable. With the exception of office systolic blood pressure (BP), predictors of the BP-lowering effect have not been identified. Because dietary sodium intake influences sympathetic drive, and, conversely, sympathetic activity influences salt sensitivity in hypertension, we investigated 24-hour urinary sodium excretion in participants of the SYMPATHY trial. SYMPATHY investigated RDN in patients with resistant hypertension. Both 24-hour ambulatory and office BP measurements were end points. No relationship was found for baseline sodium excretion and change in BP 6 months after RDN in multivariable-adjusted regression analysis. Change in the salt intake-measured BP relationships at 6 months vs baseline was used as a measure for salt sensitivity. BP was 8 mm Hg lower with similar salt intake after RDN, suggesting a decrease in salt sensitivity. However, the change was similar in the control group, and thus not attributable to RDN.

Impact of Medication Adherence on the Effect of Renal Denervation: The SYMPATHY Trial.

Randomized trials of catheter-based renal denervation (RDN) as therapy for resistant hypertension showed conflicting results in blood pressure (BP) lowering effect. Adherence to medication is modest in this patient group and may importantly drive these conflicting results. SYMPATHY is a prospective open label multicenter trial in Dutch patients with resistant hypertension. Primary outcome was change in daytime systolic ambulatory BP at 6 months. Patients were randomly assigned to RDN on top of usual care. Adherence to BP lowering drugs was assessed at baseline and follow-up, using blood samples drawn synchronously with BP measurements. Patients and physicians were unaware of the adherence assessment. Primary analyses showed a mean difference between RDN (n=95) and control (n=44) in changes in daytime systolic ambulatory BP after 6 months of 2.0 mm Hg (95% confidence interval, -6.1 to 10.2 mm Hg) in favor of control. In 80% of patients, fewer medications were detected than prescribed and adherence changed during follow-up in 31%. In those with stable adherence during follow-up, mean difference between RDN and control for daytime systolic ambulatory BP was -3.3 mm Hg (-13.7 to 7.2 mm Hg) in favor of RDN. RDN as therapy for resistant hypertension was not superior to usual care. Objective assessment of medication use shows that medication adherence is extremely poor, when patients are unaware of monitoring. Changes over time in adherence are common and affect treatment estimates considerably. Objective measurement of medication adherence during follow-up is strongly recommended in randomized trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01850901.

Renal Denervation in a Real Life Setting: A Gradual Decrease in Home Blood Pressure.

OBJECTIVES: To investigate the blood pressure dynamics after renal denervation through monthly home blood pressure measurements throughout the first 12 months. METHODS: A cohort of 70 patients performed highly standardized monthly home blood pressure monitoring during the first year after denervation according to the European Society of Hypertension guidelines. At baseline and 12 months follow-up, office and ambulatory blood pressure as well as routine physical and laboratory assessment was performed. RESULTS: Home blood pressure decreased with a rate of 0.53 mmHg/month (95% CI 0.20 to 0.86) systolic and 0.26 mmHg/month (95% CI 0.08 to 0.44) diastolic throughout 12 months of follow-up, while the use of antihypertensive medication remained stable (+0.03 daily defined doses/month, 95% CI -0.01 to 0.08). On average, a 12 month reduction of 8.1 mmHg (95% CI 4.2 to 12.0) was achieved in home systolic blood pressure, 9.3 mmHg (95% CI -14.2 to -4.4) as measured by 24-hour ambulatory blood pressure monitoring and 15.9 mmHg (95% CI -23.8 to -7.9) on office measurements. CONCLUSION: Blood pressure reduction after renal denervation occurs as a gradual decrease that extends to at least one-year follow-up. Home monitoring seems a suitable alternative for ambulatory blood pressure monitoring after renal denervation.

Renal denervation in hypertensive patients not on blood pressure lowering drugs.

INTRODUCTION: Studies on the blood pressure lowering effect of renal denervation (RDN) in resistant hypertensive patients have produced conflicting results. Change in medication usage during the studies may be responsible for this inconsistency. To eliminate the effect of medication usage on blood pressure we focused on unmedicated hypertensive patients who underwent RDN. METHODS AND RESULTS: Our study reports on a cohort of patients, who were not on blood pressure lowering drugs at baseline and during follow-up, from eight tertiary centers. Data of patients were used when they were treated with RDN and had a baseline office systolic blood pressure (SBP) ≥140 mmHg and/or 24-h ambulatory SBP ≥130 mmHg. Our primary outcome was defined as change in office and 24-h SBP at 12 months after RDN, compared to baseline. Fifty-three patients were included. There were three different reasons for not using blood pressure lowering drugs: (1) documented intolerance or allergic reaction (57 %); (2) temporary cessation of medication for study purposes (28 %); and (3) reluctance to take antihypertensive drugs (15 %). Mean change in 24-h SBP was -5.7 mmHg [95 % confidence interval (CI) -11.0 to -0.4; p = 0.04]. Mean change in office SBP was -13.1 mmHg (95 % CI -20.4 to -5.7; p = 0.001). No changes were observed in other variables, such as eGFR, body-mass-index and urinary sodium excretion. CONCLUSION: This explorative study in hypertensive patients, who are not on blood pressure lowering drugs, suggests that at least in some patients RDN lowers blood pressure.

Pathophysiology I: the kidney and the sympathetic nervous system.

Recently, catheter-based renal denervation (RDN) has become available. In order to understand better the possible role of RDN as a treatment modality, we first discuss the anatomy and function of the renal nerves in this brief review. Secondly, we address the question - what is the clinical evidence for the involvement of the kidneys and renal nerves in the pathogenesis of sympathetic hyperactivity. Finally, we will discuss how this sympathetic hyperactivity can be reduced, specifically addressing the possible role of RDN.

[A woman in acute respiratory distress]. / Een vrouw in acute ademnood.

A 59-year-old woman presented with acute respiratory distress and a superior vena cava syndrome. Her complaints were initiated by esophageal food obstruction. A CT-scan revealed a massively dilated esophagus caused by achalasia. There was compression of the trachea and the large veins of the neck. Patient underwent esophageal resection and gastric tube reconstruction.