Hypertension
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Randomized Controlled Trial Multicenter Study
Central Iliac Arteriovenous Anastomosis for Uncontrolled Hypertension: One-Year Results From the ROX CONTROL HTN Trial.
Creation of a central iliac arteriovenous anastomosis using a novel nitinol coupler device results in an immediate, significant reduction of blood pressure (BP). We present efficacy and safety findings at 12 months post-coupler insertion. This open-label, multicenter, prospective, randomized trial enrolled patients with a baseline office systolic BP ≥140 mm Hg and average daytime ambulatory BP ≥135/85 mm Hg. ⋯ In a prespecified subset of patients who failed to respond adequately to prior renal denervation, coupler therapy led to highly significant reduction in office systolic/diastolic BP (30.7/24.1 mm Hg) and significant reduction in 24-hour ambulatory systolic/diastolic BP (12.4/14.4 mm Hg) at 12 months (n=9). After coupler therapy, 14 patients (33%) developed ipsilateral venous stenosis; all were treated successfully with venous stenting. These findings confirm the importance of arterial mechanics in the pathophysiology of hypertension and support the clinical use of a central iliac arteriovenous anastomosis.
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Randomized Controlled Trial Multicenter Study
Relative and Combined Prognostic Importance of On-Treatment Mean and Visit-to-Visit Blood Pressure Variability in ONTARGET and TRANSCEND Patients.
In 28 790 patients recruited for the ONTARGET (Ongoing Treatment Alone and in Combination With Ramipril Global End Point Trials) and TRANSCEND (Telmisartan Randomized Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease) trials, we investigated the prognostic value for cardiovascular events (primary outcome) of (1)on-treatment visit-to-visit systolic blood pressure (SBP) variability versus mean SBP and (2) the 2 measures together. SBP variability was measured by the coefficient of variation (CV) of mean SBP to which it was unrelated. Confounders such as variable time and number of visits from which to calculate SBP-CV were avoided by using the same number of visits at identical times in all patients. ⋯ Prediction of the primary outcome improved by the combined use of both measures: global test for trend, P<0.0001; hazard ratio for combined fifth versus first quintile, 1.42 (1.20-1.68) compared with 1.13 (1.01-1.27) for SBP-CV and 1.24 (1.11-1.40) for mean SBP. Thus, in the present study, on-treatment mean SBP provided an overall better prediction of cardiovascular risk than visit-to-visit SBP-CV. Prediction improved by their combined use, which may thus offer a more precise estimate of the protective effect of treatment.
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Randomized Controlled Trial
Time Course of Change in Blood Pressure From Sodium Reduction and the DASH Diet.
Both sodium reduction and the Dietary Approaches to Stop Hypertension (DASH) diet lower blood pressure (BP); however, the patterns of their effects on BP over time are unknown. In the DASH-Sodium trial, adults with pre-/stage 1 hypertension, not using antihypertensive medications, were randomly assigned to either a typical American diet (control) or DASH. Within their assigned diet, participants randomly ate each of 3 sodium levels (50, 100, and 150 mmol/d, at 2100 kcal) over 4-week periods. ⋯ When comparing DASH to control, DASH changed SBP/DBP by -4.36/-1.07 mm Hg after 1 week, which accounted for most of the effect observed, with no significant difference in weekly rates of change for either SBP (P interaction=0.97) or DBP (P interaction=0.70). In the context of a typical American diet, a low-sodium diet reduced BP without plateau, suggesting that the full effects of sodium reduction are not completely achieved by 4 weeks. In contrast, compared with control, DASH lowers BP within a week without further effect thereafter.
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Randomized Controlled Trial
Effect of Uric Acid-Lowering Agents on Endothelial Function: A Randomized, Double-Blind, Placebo-Controlled Trial.
Higher levels of serum uric acid are independently associated with endothelial dysfunction, a mechanism for incident hypertension. Overweight/obese individuals are more prone to endothelial dysfunction than their lean counterparts. However, the effect of lowering serum uric acid on endothelial dysfunction in these individuals has not been examined thoroughly. ⋯ None of the interventions produced any significant change in endothelium-dependent vasodilation (probenecid, 7.4±5.1% at baseline and 8.3±5.1% at 8 weeks; allopurinol, 7.6±6.0% at baseline and 6.2±4.8% at 8 weeks; and placebo, 6.5±3.8% at baseline and 7.1±4.9% at 8 weeks). In this randomized, double-blind, placebo-controlled trial, uric acid lowering did not affect endothelial function in overweight or obese nonhypertensive individuals. These data do not support the hypothesis that uric acid is causally related to endothelial dysfunction, a potential mechanism for development of hypertension.
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Randomized Controlled Trial Multicenter Study Comparative Study
Orthostatic Hypotension in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) Blood Pressure Trial: Prevalence, Incidence, and Prognostic Significance.
Orthostatic hypotension (OH) is associated with hypertension and diabetes mellitus. However, in populations with both hypertension and diabetes mellitus, its prevalence, the effect of intensive versus standard systolic blood pressure (BP) targets on incident OH, and its prognostic significance are unclear. In 4266 participants in the ACCORD (Action to Control Cardiovascular Risk in Diabetes) BP trial, seated BP was measured 3×, followed by readings every minute for 3 minutes after standing. ⋯ Neither age nor systolic BP treatment target (intensive, <120 mm Hg versus standard, <140 mm Hg) was related to OH incidence. Over a median follow-up of 46.9 months, OH was associated with increased risk of total death (hazard ratio, 1.61; 95% confidence interval, 1.11-2.36) and heart failure death/hospitalization (hazard ratio, 1.85, 95% confidence interval, 1.17-2.93), but not with the primary outcome or other prespecified outcomes. In patients with type 2 diabetes mellitus and hypertension, OH was common, not associated with intensive versus standard BP treatment goals, and predicted increased mortality and heart failure events.