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169 result(s) for "Townsend, Raymond R."
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A Controlled Trial of Renal Denervation for Resistant Hypertension
In this large trial, denervation of the kidneys with use of a radiofrequency ablation catheter in the renal arteries had no significant effect on blood pressure in patients with resistant hypertension. This contradicts results of smaller trials that did not include a sham control. Because of the aging of the population and rising rates of obesity, hypertension is increasing in prevalence worldwide. 1 Approximately 10% of patients with diagnosed hypertension have resistant hypertension, defined as a systolic blood pressure of 140 mm Hg or higher despite adherence to at least three maximally tolerated doses of antihypertensive medications from complementary classes, including a diuretic at an appropriate dose. 1 – 4 Patients with resistant hypertension who are receiving appropriate medical therapy have high rates of cardiovascular complications, with few treatment options. The sympathetic nervous system — in particular, sympathetic cross-talk between the kidneys and the brain — appears . . .
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.
Fibroblast growth factor 23 is elevated before parathyroid hormone and phosphate in chronic kidney disease
Fibroblast growth factor 23 (FGF23) regulates phosphorus metabolism and is a strong predictor of mortality in dialysis patients. FGF23 is thought to be an early biomarker of disordered phosphorus metabolism in the initial stages of chronic kidney disease (CKD). We measured FGF23 in baseline samples from 3879 patients in the Chronic Renal Insufficiency Cohort study, which is a diverse cohort of patients with CKD stage 2–4. Mean serum phosphate and median parathyroid hormone (PTH) levels were in the normal range, but median FGF23 was markedly greater than in healthy populations, and increased significantly with decreasing estimated glomerular filtration rate (eGFR). High levels of FGF23, defined as being above 100RU/ml, were more common than secondary hyperparathyroidism and hyperphosphatemia in all strata of eGFR. The threshold of eGFR at which the slope of FGF23 increased was significantly higher than the corresponding threshold for PTH based on non-overlapping 95% confidence intervals. Thus, increased FGF23 is a common manifestation of CKD that develops earlier than increased phosphate or PTH. Hence, FGF23 measurements may be a sensitive early biomarker of disordered phosphorus metabolism in patients with CKD and normal serum phosphate levels.
Physical Performance and Frailty in Chronic Kidney Disease
Background: Poor physical performance and frailty are associated with elevated risks of death and disability. Chronic kidney disease (CKD) is also strongly associated with these outcomes. The risks of poor physical performance and frailty among CKD patients, however, are not well established. Methods: We measured the Short Physical Performance Battery (SPPB; a summary test of gait speed, chair raises and balance; range 0-12) and the five elements of frailty among 1,111 Chronic Renal Insufficiency Cohort participants. Adjusting for demographics and multiple comorbidities, we fit a linear regression model for the outcome of SPPB score and an ordinal logistic regression model for frailty status. Results: Median (interquartile range, IQR) age was 65 (57-71) years, median estimated glomerular filtration rate (eGFR) for non-dialysis patients was 49 (36-62) ml/min/1.73 m 2 , and median SPPB score was 9 (7-10). Seven percent of participants were frail and 43% were pre-frail. Compared with the SPPB score for eGFR >60 ml/min/1.73 m 2 , the SPPB was 0.51 points lower for eGFR 30-59; 0.61 points lower for eGFR 15-29, and 1.75 points lower for eGFR <15 (p < 0.01 for all comparisons). eGFR 30-59 (odds ratio, OR 1.45; p = 0.024), eGFR 15-29 (OR 2.02; p = 0.002) and eGFR <15 (OR 4.83; p < 0.001) were associated with worse frailty status compared with eGFR >60 ml/min/1.73 m 2 . Conclusions: CKD severity was associated with poor physical performance and frailty in a graded fashion. Future trials should determine if outcomes for CKD patients with frailty and poor physical performance are improved by targeted interventions.
Insulin resistance and chronic kidney disease progression, cardiovascular events, and death: findings from the chronic renal insufficiency cohort study
Background Insulin resistance contributes to the metabolic syndrome, which is associated with the development of kidney disease. However, it is unclear if insulin resistance independently contributes to an increased risk of chronic kidney disease (CKD) progression or CKD complications. Additionally, predisposing factors responsible for insulin resistance in the absence of diabetes in CKD are not well described. This study aimed to describe factors associated with insulin resistance and characterize the relationship of insulin resistance to CKD progression, cardiovascular events and death among a cohort of non-diabetics with CKD. Methods Data was utilized from Chronic Renal Insufficiency Cohort Study participants without diabetes ( N  = 1883). Linear regression was used to assess associations with insulin resistance, defined using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The relationship of HOMA-IR, fasting glucose, hemoglobin A1c (HbA1c), and C-peptide with CKD progression, cardiovascular events, and all-cause mortality was examined with Cox proportional hazards models. Results Novel positive associations with HOMA-IR included serum albumin, uric acid, and hemoglobin A1c. After adjustment, HOMA-IR was not associated with CKD progression, cardiovascular events, or all-cause mortality. There was a notable positive association of one standard deviation increase in HbA1c with the cardiovascular endpoint (HR 1.16, 95% CI: 1.00–1.34). Conclusion We describe potential determinants of HOMA-IR among a cohort of non-diabetics with mild-moderate CKD. HOMA-IR was not associated with renal or cardiovascular events, or all-cause mortality, which adds to the growing literature describing an inconsistent relationship of insulin resistance with CKD-related outcomes.
Aortic PWV in Chronic Kidney Disease: A CRIC Ancillary Study
Background Aortic pulse wave velocity (PWV) is a measure of arterial stiffness and has proved useful in predicting cardiovascular morbidity and mortality in several populations of patients, including the healthy elderly, hypertensives and those with end-stage renal disease receiving hemodialysis. Little data exist characterizing aortic stiffness in patients with chronic kidney disease (CKD) who are not receiving dialysis, and in particular the effect of reduced kidney function on aortic PWV. Methods We performed measurements of aortic PWV in a cross-sectional cohort of participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study to determine factors which predict increased aortic PWV in CKD. Results PWV measurements were obtained in 2,564 participants. The tertiles of aortic PWV (adjusted for waist circumference) were <7.7m/s, 7.7–10.2m/s, and >10.2m/s with an overall mean (± s.d.) value of 9.48 ± 3.03m/s (95% confidence interval = 9.35–9.61m/s). Multivariable regression identified significant independent positive associations of age, blood glucose concentrations, race, waist circumference, mean arterial blood pressure, gender, and presence of diabetes with aortic PWV and a significant negative association with the level of kidney function. Conclusions The large size of this unique cohort, and the targeted enrollment of CKD participants provides an ideal situation to study the role of reduced kidney function as a determinant of arterial stiffness. Arterial stiffness may be a significant component of the enhanced cardiovascular risk associated with kidney failure.
Effect of renal denervation in attenuating the stress of morning surge in blood pressure: post-hoc analysis from the SPYRAL HTN-ON MED trial
BackgroundCatheter-based renal denervation (RDN) reduces blood pressure (BP) throughout the 24-h period, as reported in several randomized sham-controlled trials. Reduction of BP in the early morning hours is especially important due to increased cardiovascular risks during that time.ObjectiveIn this report, we examine the impact of RDN on systolic BP (SBP) and diastolic BP (DBP) during the critical morning surge period in a post-hoc analysis of patients in the SPYRAL HTN-ON MED trial.Methods and resultsAmbulatory BP measurements were collected at baseline and 6 months for treatment and control patient groups over 24-h periods. Average morning BP surge is the difference between average morning BP and average nighttime BP, and the morning surge slope reflects the rate of change of BP from nighttime to morning. Mean morning DBP surge slopes were significantly lower for RDN vs. control groups at 6 months (1.1 vs. 3.6 mmHg/h; p = 0.029). In the RDN group, morning DBP surge slopes were significantly lower at 6 months compared to baseline (1.1 vs. 4.1 mmHg/h; p = 0.006). Similar patterns were observed for mean morning SBP surge slope but did not reach statistical significance.ConclusionsThis decrease in the morning DBP surge slope, an index of the sympathetically-mediated morning BP surge, thus indicates a drop in late morning BP relative to early morning/nocturnal BP in the RDN group. Thus, RDN appears effective in attenuating the slope of morning surge in DBP that might indicate possible benefits in a high-risk hypertensive population.Clinical trial registrationhttps://www.clinicaltrials.gov (NCT02439775), registered May 12, 2015.
Association between Inflammation and Cardiac Geometry in Chronic Kidney Disease: Findings from the CRIC Study
Left ventricular hypertrophy (LVH) and myocardial contractile dysfunction are independent predictors of mortality in patients with chronic kidney disease (CKD). The association between inflammatory biomarkers and cardiac geometry has not yet been studied in a large cohort of CKD patients with a wide range of kidney function. Plasma levels of interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), IL-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, high-sensitivity C-Reactive protein (hs-CRP), fibrinogen and serum albumin were measured in 3,939 Chronic Renal Insufficiency Cohort study participants. Echocardiography was performed according to the recommendations of the American Society of Echocardiography and interpreted at a centralized core laboratory. LVH, systolic dysfunction and diastolic dysfunction were present in 52.3%, 11.8% and 76.3% of the study subjects, respectively. In logistic regression analysis adjusted for age, sex, race/ethnicity, diabetic status, current smoking status, systolic blood pressure, urinary albumin- creatinine ratio and estimated glomerular filtration rate, hs-CRP (OR 1.26 [95% CI 1.16, 1.37], p<0.001), IL-1RA (1.23 [1.13, 1.34], p<0.0001), IL-6 (1.25 [1.14, 1.36], p<0.001) and TNF-α (1.14 [1.04, 1.25], p = 0.004) were associated with LVH. The odds for systolic dysfunction were greater for subjects with elevated levels of hs-CRP (1.32 [1.18, 1.48], p<0.001) and IL-6 (1.34 [1.21, 1.49], p<0.001). Only hs-CRP was associated with diastolic dysfunction (1.14 [1.04, 1.26], p = 0.005). In patients with CKD, elevated plasma levels of hs-CRP and IL-6 are associated with LVH and systolic dysfunction.
Long-term efficacy and safety of renal denervation in the presence of antihypertensive drugs (SPYRAL HTN-ON MED): a randomised, sham-controlled trial
Renal denervation has been shown to lower blood pressure in the presence of antihypertensive medications; however, long-term safety and efficacy data from randomised trials of renal denervation are lacking. In this pre-specified analysis of the SPYRAL HTN-ON MED study, we compared changes in blood pressure, antihypertensive drug use, and safety up to 36 months in renal denervation versus a sham control group. This randomised, single-blind, sham-controlled trial enrolled patients from 25 clinical centres in the USA, Germany, Japan, the UK, Australia, Austria, and Greece, with uncontrolled hypertension and office systolic blood pressure between 150 mm Hg and 180 mm Hg and diastolic blood pressure of 90 mm Hg or higher. Eligible patients had to have 24-h ambulatory systolic blood pressure between 140 mm Hg and less than 170 mm Hg, while taking one to three antihypertensive drugs with stable doses for at least 6 weeks. Patients underwent renal angiography and were randomly assigned (1:1) to radiofrequency renal denervation or a sham control procedure. Patients and physicians were unmasked after 12-month follow-up and sham control patients could cross over after 12-month follow-up completion. The primary endpoint was the treatment difference in mean 24-h systolic blood pressure at 6 months between the renal denervation group and the sham control group. Statistical analyses were done on the intention-to-treat population. Long-term efficacy was assessed using ambulatory and office blood pressure measurements up to 36 months. Drug surveillance was used to assess medication use. Safety events were assessed up to 36 months. This trial is registered with ClinicalTrials.gov, NCT02439775; prospectively, an additional 260 patients are currently being randomly assigned as part of the SPYRAL HTN-ON MED Expansion trial. Between July 22, 2015, and June 14, 2017, among 467 enrolled patients, 80 patients fulfilled the qualifying criteria and were randomly assigned to undergo renal denervation (n=38) or a sham control procedure (n=42). Mean ambulatory systolic and diastolic blood pressure were significantly reduced from baseline in the renal denervation group, and were significantly lower than the sham control group at 24 and 36 months, despite a similar treatment intensity of antihypertensive drugs. The medication burden at 36 months was 2·13 medications (SD 1·15) in the renal denervation group and 2·55 medications (2·19) in the sham control group (p=0·26). 24 (77%) of 31 patients in the renal denervation group and 25 (93%) of 27 patients in the sham control group adhered to medication at 36 months. At 36 months, the ambulatory systolic blood pressure reduction was −18·7 mm Hg (SD 12·4) for the renal denervation group (n=30) and −8·6 mm Hg (14·6) for the sham control group (n=32; adjusted treatment difference −10·0 mm Hg, 95% CI −16·6 to −3·3; p=0·0039). Treatment differences between the renal denervation group and sham control group at 36 months were −5·9 mm Hg (95% CI −10·1 to −1·8; p=0·0055) for mean ambulatory diastolic blood pressure, −11·0 mm Hg (−19·8 to −2·1; p=0·016) for morning systolic blood pressure, and −11·8 mm Hg (−19·0 to −4·7; p=0·0017) for night-time systolic blood pressure. There were no short-term or long-term safety issues associated with renal denervation. Radiofrequency renal denervation compared with sham control produced a clinically meaningful and lasting blood pressure reduction up to 36 months of follow-up, independent of concomitant antihypertensive medications and without major safety events. Renal denervation could provide an adjunctive treatment modality in the management of patients with hypertension. Medtronic.
Renal Denervation for Hypertension: From Innovation to Indication
High blood pressure is a common problem around the world. Although many trials attest to the value of reducing blood pressure with medication and lifestyle changes, current prevalence studies of high blood pressure show a substantial portion of the adult population with uncontrolled high blood pressure. Treatment nonadherence is part of the challenge to achieving blood pressure control and newer approaches to high blood pressure treatment, whether device based, or using agents such as silencing ribonucleic acids, have shown high levels of treatment efficacy and since they are administered in the health care setting, adherence is less of an issue. In this introduction to a special issue of the American Journal of Cardiology we will review the history of hypertension treatment and some current epidemiology highlighting the public health importance of improving blood pressure control to reap the well described benefits of lower blood pressure upon the target organs of hypertension. Subsequent sections of this special issue will focus on aspects of renal denervation, including patient selection, efficacy in blood pressure lowering, measuring success of denervation and procedural guidance for this emerging therapy in the management of uncontrolled hypertension.