Effect of empagliflozin on ketone bodies in patients with stable chronic heart failure.

BACKGROUND: Recent studies indicated that sodium glucose cotransporter (SGLT)2 inhibition increases levels of ketone bodies in the blood in patients with type 1 and 2 diabetes. Other studies suggested that in patients with chronic heart failure (CHF), increased myocardial oxygen demand can be provided by ketone bodies as a fuel substrate. Experimental studies reported that ketone bodies, specifically beta-hydroxybutyrate (ß-OHB) may increase blood pressure (BP) by impairing endothelium-dependant relaxation, thereby leading to increased vascular stiffness. In our study we assessed whether the SGLT 2 inhibition with empagliflozin increases ketone bodies in patients with stable CHF and whether such an increase impairs BP and vascular function. METHODS: In a prospective, double blind, placebo controlled, parallel-group single centre study 75 patients with CHF (left ventricular ejection fraction 39.0 ± 8.2%) were randomised (2:1) to the SGLT-2 inhibitor empagliflozin 10 mg orally once daily or to placebo, 72 patients completed the study. After a run-in phase we evaluated at baseline BP by 24 h ambulatory blood pressure (ABP) monitoring, vascular stiffness parameters by the SphygmoCor system (AtCor Medical, Sydney, NSW, Australia) and fasting metabolic parameters, including ß-OHB by an enzymatic assay (Beckman Coulter DxC 700 AU). The same measurements were repeated 12 weeks after treatment. In 19 of the 72 patients serum levels of ß-OHB were beneath the lower border of our assay (< 0.05 mmol/l) therefore being excluded from the subsequent analysis. RESULTS: In patients with stable CHF, treatment with empagliflozin (n = 36) was followed by an increase of ß-OHB by 33.39% (p = 0.017), reduction in 24 h systolic (p = 0.038) and diastolic (p = 0.085) ABP, weight loss (p = 0.003) and decrease of central systolic BP (p = 0.008) and central pulse pressure (p = 0.008). The increase in ß-OHB was related to an attenuated decrease of empagliflozin-induced 24 h systolic (r = 0.321, p = 0.069) and diastolic (r = 0.516, p = 0.002) ABP and less reduction of central systolic BP (r = 0.470, p = 0.009) and central pulse pressure (r = 0.391, p = 0.033). No significant changes were seen in any of these parameters after 12 weeks of treatment in the placebo group (n = 17). CONCLUSION: In patients with stable CHF ketone bodies as assessed by ß-OHB increased after treatment with empagliflozin. This increase led to an attenuation of the beneficial effects of empagliflozin on BP and vascular parameters. Trial registration The study was registered at http://www.clinicaltrials.gov (NCT03128528).

[European guidelines for the management of arterial hypertension 2018-what has changed?] / Europäische Hypertonieleitlinien 2018 ­ was ändert sich?

BACKGROUND: In November 2017, the latest American guidelines for the management of arterial hypertension were published. With these guidelines lowering the threshold for hypertension to 130/80 mm Hg, the latest European guidelines were expected with excitement. OBJECTIVES: This article gives an overview on the European Society of Cardiology (ESC) and European Society of Hypertension (ESH) 2018 guidelines for the management of arterial hypertension, thereby identifying the most relevant changes in comparison to previous guidelines. CURRENT DATA: The latest 2018 ESC/ESH guidelines adhere to the previous definition of hypertension, in which a blood pressure of 140/90 mm Hg is considered as threshold for diagnosis. In contrast, there was a change in blood pressure treatment target from below 140/90 to between 120-129/70-79 mm Hg in patients < 65 years if well tolerated. Among patients ≥ 65 years, a systolic blood pressure between 130 and 139 mm Hg is recommended, whereas a diastolic blood pressure between 70 and 79 mm Hg should be targeted. Additionally the guidelines recommend the use of fixed dose combinations as first choice instead of monotherapy to improve adherence. Interventional treatment strategies should only be applied in carefully selected patients at experienced centers and are not recommended outside of clinical studies and registers. Furthermore, the chapters regarding initiation of blood pressure-lowering therapy and clinical evaluation as well as management of hypertension emergencies have been outlined. CONCLUSIONS: The latest European guidelines for the management of hypertension include several changes. One of the most important aspects is that-in contrast to the American guidelines-the threshold for diagnosis remains at 140/90 mm Hg, whereas treatment target range has been lowered by roughly 10 mm Hg and single pill fixed dose combinations are recommended.

[Comments on the guidelines (2018) of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH) on the management of arterial hypertension]. / Kommentar zu den Leitlinien (2018) der Europäischen Gesellschaft für Kardiologie (ESC) und der Europäischen Gesellschaft für Hypertonie (ESH) für das Management der arteriellen Hypertonie.

Arterial hypertension represents one of the most frequent chronic diseases that can lead to complications, such as stroke, dementia, heart attack, heart failure and renal failure. By 2025 the number of hypertensive patients will increase to approximately 1.6 billion people worldwide. The new guidelines of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH) on the management of arterial hypertension replace the guidelines of the ESC/ESH from 2013. The 2018 guidelines of the ESC/ESH were adopted by the German Cardiac Society and the German Hypertension League. In these comments national characteristics are worked out and the essential new aspects of the guidelines are critically discussed. These include, for example, the definition of hypertension, the importance of out of office blood pressure measurements, revised blood pressure targets, the modified algorithm for drug treatment and the relevance of device-based hypertension treatments. Important aspects for the management of hypertensive emergencies are also presented.

SGLT-2-inhibition with dapagliflozin reduces tissue sodium content: a randomised controlled trial.

BACKGROUND AND AIMS: Sodium tissue content by 23Na magnetic resonance imaging (Na-MRI) has been validated in experimental and human studies. SGLT-2 inhibition blocks the reabsorption of glucose and of sodium in the proximal tubular cells in a 1:1 fashion. We hypothesized that SGLT-2 inhibition in patients with type 2 diabetes characterized by sodium retention leads to decreased tissue sodium content due to its pharmacological action. MATERIALS AND METHODS: In a prospective double blind, placebo controlled, cross-over trial 59 patients (61 ± 7.6 years) with type 2 diabetes were randomized to either dapagliflozin 10 mg or placebo once daily for 6 weeks each. In addition to metabolic parameters and ambulatory blood pressure (BP) we analysed the sodium content in the skin and muscles of the lower leg by Na-MRI. RESULTS: Compared to baseline 6 weeks treatment with the SGLT-2 inhibitor dapagliflozin decreased fasting (132 ± 28 vs. 114 ± 19 mg/dl, p < 0.001), postprandial blood glucose (178 ± 66 mg/dl vs. 153 ± 46 mg/dl, p < 0.001), body weight (87.6 vs. 86.6 kg, p < 0.001) and systolic (129 ± 12 vs. 126 ± 11 mmHg, p = 0.010), and diastolic (77.4 ± 9 vs. 75.6 ± 8 mmHg, p = 0.024), 24-h ambulatory BP. Tissue sodium content in the skin was reduced after 6 weeks treatment with dapagliflozin compared to baseline [24.1 ± 6.6 vs. 22.7 ± 6.4 A.U.(arbitrary unit) p = 0.013]. No significant reduction of tissue sodium content was observed in the muscle (M. triceps surae: 20.5 ± 3.5 vs. 20.4 ± 3.7 A.U. p = 0.801). No clear significant difference in tissue water content of muscle and skin was observed after 6 weeks of treatment with dapagliflozin, compared to baseline. CONCLUSION: SGLT-2 inhibition with dapagliflozin resulted in a significant decrease in tissue sodium content of the skin after 6 weeks. This observation point to a decrease of total sodium content in patients with type 2 diabetes prone to cardiovascular complications, that might be mitigated by SGLT-2 inhibition. Trial registration The study was registered at http://www.clinicaltrials.gov (NCT02383238) retrospectively registered.

Low resting heart rates are associated with new-onset atrial fibrillation in patients with vascular disease: results of the ONTARGET/TRANSCEND studies.

BACKGROUND: Elevated systolic blood pressure (SBP) and high resting heart rate (HR) are associated with cardiovascular end-points. Although the association between atrial fibrillation (AF) and SBP is well established, the relation between AF and HR remains unclear. METHODS: In patients from the ONTARGET and TRANSCEND studies with high cardiovascular disease risk (n = 27 064), new-onset AF was evaluated in relation to mean SBP, visit-to-visit variation in SBP (SBP-CV; i.e. SD/mean × 100%), mean HR and visit-to-visit variation in HR (HR-CV). RESULTS: Low mean HR (P < 0.0001) and high SBP (P = 0.0021) were associated with incident AF. High SBP-CV (P = 0.031) and HR-CV (P < 0.0001) were also associated with incident AF. After adjustment for confounders, SBP and SBP-CV were no longer significantly associated with AF. The detrimental effect of low HR was particularly evident in subjects who were not receiving treatment with beta-blockers (P = 0.014 for interaction between beta-blocker use and mean HR). In addition to low HR, high HR-CV and high SBP had additive effects on incident AF. CONCLUSIONS: Low mean HR (<60 beats min(-1) ) is independently associated with incident AF, and low HR-CV and high SBP further increase the incidence of new-onset AF in patients at high risk of cardiovascular disease.

Resting heart rate is associated with renal disease outcomes in patients with vascular disease: results of the ONTARGET and TRANSCEND studies.

BACKGROUND: Resting heart rate (RHR) is associated with cardiovascular disease outcomes in high-risk patients. It is not known whether RHR is predictive of renal outcomes such as albuminuria, end-stage renal disease (ESRD) or doubling of creatinine. We evaluated whether RHR could predict renal endpoints in patients at a high risk of cardiovascular disease. We also tested the effects of RHR at different levels of systolic blood pressure (SBP). METHODS: We analysed data from 28 757 patients in the ONTARGET and TRANSCEND trials. RHR and SBP were available for a mean of 4.9 ± 0.4 visits (range 3-5) within the first 2 years of the studies. Albuminuria was determined at baseline, at 2 years and at study end. RESULTS: Mean RHR was predictive of incident micro-albuminuria [hazard ratio (HR) for RHR ≥80 vs. <60 beats min(-1) 1.49, 95% confidence interval (CI) 1.29-1.71, P < 0.0001], incident macro-albuminuria (HR 1.84, 95% CI 1.39-2.42, P < 0.0001), doubling of creatinine (HR 1.47, 95% CI 1.00-2.17, P = 0.050) and ESRD (HR 1.78, 95% CI 1.00-3.16, P = 0.050), and the combined renal end-point (HR 1.51, 95% CI 1.32-1.74, P < 0.0001). Associations were robust at SBPs from <120 to ≥150 mmHg, with the lowest risk at a SBP of 130-140 mmHg. CONCLUSION: Resting heart rate is a potent predictor of these renal outcomes, as well as their combination, in patients with cardiovascular disease. RHR at all SBP levels should be considered as a possible renal disease risk predictor and should be investigated as a treatment target with RHR-reducing agents.

Prognostic model for total mortality in patients with haemodialysis from the Assessments of Survival and Cardiovascular Events (AURORA) study.

OBJECTIVES: Risk factors of mortality in patients with haemodialysis (HD) have been identified in several studies, but few prognostic models have been developed with assessments of calibration and discrimination abilities. We used the database of the Assessment of Survival and Cardiovascular Events study to develop a prognostic model of mortality over 3-4 years. METHODS: Five factors (age, albumin, C-reactive protein, history of cardiovascular disease and diabetes) were selected from experience and forced into the regression equation. In a 67% random try-out sample of patients, no further factors amongst 24 candidates added significance (P < 0.01) to mortality outcome as assessed by Cox regression modelling, and individual probabilities of death were estimated in the try-out and test samples. Calibration was explored by calculating the prognostic index with regression coefficients from the try-out sample to patients in the 33% test sample. Discrimination was assessed by receiver operating characteristic (ROC) areas. RESULTS: The strongest prognostic factor in the try-out sample was age, with small differences between the other four factors. Calibration in the test sample was good when the calculated number of deaths was multiplied by a constant of 1.33. The five-factor model discriminated reasonably well between deceased and surviving patients in both the try-out and test samples with an ROC area of about 0.73. CONCLUSIONS: A model consisting of five factors can be used to estimate and stratify the probability of death for individuals The model is most useful for long-term prognosis in an HD population with survival prospects of more than 1 year.

Rosuvastatin improves pulse wave reflection by restoring endothelial function.

One of the major indicators of intact endothelial function is basal nitric oxide (NO) activity. Further, it seems to be likely that statin therapy exerts beneficial effects on vascular function, at least in part via an improvement of NO bioavailability. In the present double-blind crossover study 29 hypercholesterolemic patients were randomly assigned to receive rosuvastatin and placebo for 42days. Pulse wave analysis was assessed after 30min of rest (baseline) and after infusion of N(G)-monomethyl-l-arginine (l-NMMA) at the end of 42days treatment period. The magnitude of the increase in central augmentation index (cAIx) in response to inhibition of NO synthase (NOS) by l-NMMA is indicative of basal NO activity. CAIx was significantly lower (18.3±10 versus 21.9±12%, p=0.027) with rosuvastatin compared to placebo. There was no increment of cAIx in response to l-NMMA in placebo group. In contrast, cAIx increased significantly in response to l-NMMA (20.5±11 versus 25.7±10mm Hg, p=0.001) in rosuvastatin group. The percentage of increase of cAIx tended to be more pronounced after treatment with rosuvastatin compared to placebo (53.7±92 versus 14.1±36%, p=0.087). Pulse pressure amplification (PPA) improved (1.31±0.2 versus 1.26±0.2%, p=0.016) after rosuvastatin compared to placebo. Regression analyses revealed that both LDL-cholesterol and CRP-levels are independent determinants of basal NO activity improvement, which itself is an independent determinant of vascular function, expressed by an improvement of pulse wave reflection and PPA. In this placebo controlled study, treatment with rosuvastatin improved vascular and endothelial function. Determinants for improved NO production in patients with hypercholesterolemia were the achieved levels of LDL-cholesterol and CRP. Overall, in patients without CV disease, rosuvastatin exerted beneficially effect on vascular dysfunction, one of the earliest manifestation of atherosclerosis.

[Comparison of early retinal microvascular changes and microalbuminuria as indicators for increased cardioascular risk]. / Vergleich von frühen Veränderungen der retinalen Mikrostrombahn und Mikroalbuminurie als Zeichen eines erhöhten kardiovaskulären Risikos.

INTRODUCTION: Prevention of cardiovascular disease is an important goal in clinical medicine and public health. In the process, the diagnosis of early end-organ damage is a priority beside the treatment of classic cardiovascular risk factors. To achieve this, the ophthalmoscopic examination of the retinal vessels plays a prominent role. Alternatively, the quantification of low quantities of albumin in the urine (microalbuminuria) allows the detection of early vascular damage in the kidney. The question is addressed as to whether these two methods are interchangeable or are rather complementary. PATIENTS AND METHODS: We examined 226 members of the staff of the University Hospital Erlangen who volunteered to participate in a preventive campaign. A comprehensive history was taken, and height, weight and blood pressure were measured. Analysis of serum lipids and determination of the urinary albumin/creatinine ratio were performed. Fotos of the central fundus were taken with a non-mydriatic camera and analysed by an experienced ophthalmologist in a standardised fashion. The risk for cardiovascular mortality within the next ten years was estimated from age, sex, blood pressure and serum cholesterol using the euroSCORE tables for Germany. RESULTS: There was no signficant correlation between the arteriovenous ratio of the retinal vessels and the urinary albumin/creatinine ratio. Neither parameter correlated with the euroSCORE Germany. Arteriovenous crossings and focal narrowing of the retinal vessels were associated signficantly with an elevated euroSCORE risk. CONCLUSIONS: In large population-based studies, the arteriovenous ratio and the urinary albumin/creatinine ratio have been confirmed as markers of cardiovascular risk. In our study, there was no correlation between these two parameters. Thus, they seem to present independent risk markers. The presence of arteriovenous crossings and focal narrowing seems to be linked more closely to the classic cardiovascular risk factors from which the euroSCORE is calculated. The ophathlmolscopic examination of retinal vessels and the analysis of urinary albumin/creatinine ratio seem to complement rather than replace each other.

Change in augmentation index during NOS inhibition, an index of basal NO production, is an independent determinant of large-artery function.

BACKGROUND/AIMS: Arterial wave reflection, measured as augmentation index (AIx), and central pulse pressure (PP) closely predict cardiovascular events. We hypothesized that basal nitric oxide (NO) production would be a determinant of AIx and central PP. METHODS: AIx and central PP were assessed at baseline by pulse wave analysis in 86 male subjects across a wide range of age, blood pressure and lipid values. The basal NO production in the cardiovascular system was then determined as change in AIx during NO synthase blockade with N(G)-monomethyl-L-arginine (L-NMMA, 3.25 mg/kg). RESULTS: AIx increased from 17.5 ± 14.6 to 23.1 ± 14.2 during L-NMMA infusion (p < 0.001). The increase in AIx during NO synthase blockade, an index of basal NO production, was inversely related to baseline central AIx and PP, and positively to PP amplification. Multiple linear regression analyses disclosed that in addition to age and mean blood pressure, change of AIx to L-NMMA is a strong and independent determinant of baseline central AIx, central PP and PP amplification. CONCLUSION: Greater change of AIx to L-NMMA, an index of basal NO production, is associated with better large-artery function. Therefore, therapeutic interventions which increase the basal NO production might be particularly effective in reducing cardiovascular risk.

Relation of the first hypertension-associated event with medication, compliance and persistence in naïve hypertensive patients after initiating monotherapy.

OBJECTIVE: To analyze the relation of medication, compliance and persistence with the risk of the first hypertension associated event in naïve hypertensive patients after initiating monotherapy with any of the first-line antihypertensive drug classes. METHODS: A retrospective cohort study in the IMS Disease Analyzer database was performed. The study cohort comprised all previously untreated hypertensive patients who were free from hypertension-associated comorbidities, in whom new monotherapy with angiotensin II receptor blockers (ARBs), ACE-inhibitors (ACEIs), beta-blockers (BBs), calcium channel blockers (CCBs) or diuretics was initiated. Compliance and persistence were determined within 2 years. The relation between medication, compliance, persistence and risk of the first hypertension-associated event was analyzed using a Cox regression model. Outcomes in the ARB cohort were compared with outcomes in each other drug class cohort separately and with outcomes in the group of non-ARBs (pooled data). RESULTS: 7,661 patients were identified with a follow-up of at least 2 years (totaling 45,585 patient-years of follow-up). ARBs were associated with more favorable measures (all p < 0.05) of compliance (0.86 vs. 0.82 and 0.74, respectively) and persistence (509 days vs. 459 and 324 days) compared with the group of non-ARBs and diuretics, respectively. The risk of the first hypertension-associated event was higher (all p < 0.05) with diuretics (adjusted hazard ratio (aHR) 0.68), BBs (0.79), CCBs (0.78), and the group of non-ARBs (0.81) and was similar with ACEIs (aHR 0.93, p = 0.37) compared to ARBs. Overall, high compliance was associated with a reduced risk of the first event (p < 0.05). CONCLUSION: Our real-world data suggest that initiating a treatment with ARB monotherapy shows significant benefits in most outcomes including hypertension-related complications compared to other antihypertensive drug monotherapies. The documented impact of compliance on the risk of the first event should have clinical and policy implications.

Elevated VEGF-plasma levels in young patients with mild essential hypertension.

BACKGROUND: Growing evidence shows that inflammation plays a pivotal role in the pathophysiology of essential hypertension (EH). Vascular endothelial cell growth factor (VEGF) is currently discussed as a possible mediator of inflammation. To investigate the hypothesis that VEGF plays a role as an inflammatory mediator in EH we performed the present pilot study of young patients in a very early stage of EH. MATERIALS AND METHODS: 15 young patients with mild EH [33.8 +/- 7.3 years, systolic blood pressure (SBP): 143.8 +/- 10.5 mmHg, diastolic blood pressure (DBP): 88.2 +/- 11.1 mmHg, mean arterial pressure (MAP) 106.6 +/- 10.4 mmHg] and 15 healthy controls (31.7 +/- 10.6 years) were examined. Blood was drawn from a peripheral vein and serum levels of VEGF, monocyte-chemoattractant-protein (MCP)-1, high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, and tumour-necrosis-factor (TNF)-alpha were measured via commercially available enzyme-linked immunoassays. RESULTS: Hypertensives showed increased plasma levels of VEGF (P < 0.05) and MCP-1 (P < 0.05). VEGF positively correlated with MAP (r = 0.46, P < 0.05) and MCP-1 (r = 0.63, P < 0.01). Multivariate analysis demonstrated VEGF to be an independent predictor of MCP-1 levels. Furthermore, hypertensives had higher levels of hsCRP (P < 0.01), IL-6 (P < 0.001) and TNF-alpha (P < 0.05). IL-6 levels correlated with SBP (r = 0.59, P < 0.001), DBP (r = 0.67, P < 0.001) and MAP (r = 0.46, P < 0.001). A significant positive correlation was also found between hsCRP levels and SBP (r = 0.39, P < 0.05). CONCLUSIONS: This pilot study demonstrates that in an early state of EH, inflammatory pathways have already been activated. Besides classical pro-inflammatory cytokines, VEGF serum levels are significantly elevated. The positive correlation of VEGF with MCP-1 is suggestive for the already described induction of MCP-1 via VEGF.

Efficacy, safety and tolerability of valsartan 80 mg compared to irbesartan 150 mg in hypertensive patients on long-term hemodialysis (VALID study).

BACKGROUND: End stage renal disease (ESRD) patients mainly die of cardiovascular disease, and hypertension is regarded as the major risk factor. Valsartan is an angiotensin receptor blocker (ARB) with a well-established efficacy and safety profile in hypertensive patients, but with relatively few data in patients on hemodialysis (HD). The aim of this 2 A 5-week, open-label, multicenter, randomized cross-over study was to investigate whether valsartan (Val) 80 mg is as effective, safe and well-tolerated as irbesartan (Irb) 150 mg in patients with arterial hypertension on long-term hemodialysis. METHODS: After a wash-out of previous ARBs for 1 week, 67 patients (ITT) on long-term hemodialysis, between 18 and 80 years, with mean supine systolic blood pressure (MSupSBP) >or= 140 mmHg and < 180 mmHg were randomized to either Val 40 or Irb 75 for 1 week with forced titration to Val 80 or Irb 150 for another 4 weeks. After a second wash-out period of 1 week, patients were switched from Val to Irb or vice versa for another 5 weeks (1 week low-dose, 4 weeks target dose). The primary objective was non-inferiority of Val versus Irb on predialytic MSupSBP. Secondary objectives were predialytic MSupDBP, adverse events (AEs), laboratory abnormalities, hypotension during and after dialysis and quality of life. BP values are given as mean A+/- SD. RESULTS: Baseline BP values were 158 A+/- 11 / 78 A+/- 13 mmHg (Val) and 161 A+/- 13 / 83 A+/- 10 mmHg (Irb). The predialytic MSupSBP and MSupDBP after 4 weeks of treatment were similar in both treatment groups (Val 150 A+/- 19 / 79 A+/- 13 mmHg; Irb 151 A+/- 16 / 78 A+/- 14 mmHg). Most of the reported AEs were mild to moderate. The percentage of AEs considered by the investigator to be possibly drug-related was similar between both groups: 15.4% in the valsartan group and 20.4% in the irbesartan group. The most common AEs were nausea, muscle spasms and nasopharyngitis. Eight SAEs occurred, four in each treatment group (all not drug-related), including one death (cardiovascular insufficiency) in the Irb group. Laboratory changes were similar in both groups and not clinically relevant. The number of patients with symptomatic hypotension was similar during (9% each) as well as after dialysis (1.3% each). The quality of life data (SF-36) were comparable for each category. CONCLUSIONS: Valsartan 80 mg is as effective, safe and well tolerated as irbesartan 150 mg in hypertensive patients on chronic hemodialysis.

1166 A/C polymorphism of the angiotensin II type 1 receptor gene and the response to short-term infusion of angiotensin II.

BACKGROUND: Previous studies reported an association of the 1166 A/C polymorphism of the angiotensin II (Ang II) type 1 receptor gene with high blood pressure and cardiovascular disease. We tested the hypothesis that this polymorphism affects the blood-pressure, renal hemodynamic, and aldosterone response to infused Ang II. METHODS AND RESULTS: Young, male, white volunteers (n = 116) with normal (n = 65) or mildly elevated (n = 51) blood pressure on a high salt intake were genotyped for the 1166 A/C polymorphism. Two doses of Ang II (0.5 and 3 ng x kg(-1) x min(-1) over 30 minutes each) increased blood pressure, plasma aldosterone, glomerular filtration rate, and filtration fraction and decreased renal blood flow. The blood-pressure, renal hemodynamic, and aldosterone responses were not significantly different between subjects homozygous for the A allele (n = 56) and heterozygous subjects (n = 47) or subjects homozygous for the C allele (n = 13). Comparison of A allele homozygotes with all C allele carriers pooled (n = 60) or restriction of the analysis to normotensive volunteers also revealed no significant differences between genotypes. CONCLUSIONS: The 1166 C variant of the Ang II type 1 receptor does not lead to a greater blood-pressure, aldosterone, or renal vascular response to infused Ang II in young, male, white subjects. We conclude that the 1166 A/C polymorphism does not have a major effect on these actions of Ang II.

Central blood volume: a determinant of early cardiac adaptation in arterial hypertension?

OBJECTIVES: This study was undertaken to assess the influence of the fluid volume state on cardiac adaptation to hypertension. BACKGROUND: Left ventricular hypertrophy is an important predictor of hypertensive complications. We analyzed volume status and its impact on cardiac structural changes in early hypertension. METHODS: In 33 normotensive subjects, 40 patients with borderline hypertension and 63 patients with established essential hypertension, mean arterial pressure was measured invasively; total blood volume was measured by iodine-125-labeled plasma albumin and hematocrit; central blood volume by indocyanine green dye dilution curve; and diastolic diameter and left ventricular mass by two-dimensional-guided M-mode echocardiography. RESULTS: Central blood volume was approximately 20% higher in patients with stage I borderline hypertension than in normotensive subjects ([mean +/- SD] 3,001 +/- 663 vs. 2,493 +/- 542 ml, p < 0.05), whereas total blood volume was similar in all three groups. This shift in intravascular volume toward the cardiopulmonary circulation was accompanied by a significant increase in diastolic diameter (5.29 +/- 0.80 vs. 4.86 +/- 0.77 cm, p < 0.05) and in left ventricular mass (239.4 +/- 90.6 vs. 183.5 +/- 68.8 g, p < 0.05) in patients with borderline hypertension compared with subjects with normotension. In patients with established essential hypertension, volume status of stroke volume and diastolic dimension returned to normal values, whereas left ventricular mass increased further. CONCLUSIONS: We conclude that the early phase of hypertension is characterized by centripetal distribution of intravascular volume, leading to an increased preload to the left ventricle. This change in volume status appears to be related to cardiac structural adaptation to an increase in arterial pressure.

Effect of the angiotensin II type 2-receptor gene (+1675 G/A) on left ventricular structure in humans.

OBJECTIVES: Our study goal was to analyze whether gene variants of angiotensin II type 2-receptor (AT2-R) modulate the effects of angiotensin II on the left ventricle (LV). BACKGROUND: Experimental data suggest that angiotensin II modifies ventricular growth responses via angiotensin II type 1-receptors (AT1-R) and AT2-R. METHODS: In 120 white, young male subjects with normal or mildly elevated blood pressure, we assessed plasma angiotensin II and aldosterone concentrations (RIA), 24-h urinary sodium excretion, 24-h ambulatory blood pressure and LV structure (two-dimensional guided M-mode echocardiography). The intronic +1675 G/A polymorphism of the X-chromosomal located AT2-R gene was investigated by single-strand conformational polymorphism analysis and DNA-sequencing. RESULTS: Hypertensive subjects with the A-allele had a greater LV posterior (11.0 +/- 1.3 vs. 9.9 +/- 1.3 mm, p < 0.001), septal (11.8 +/- 1.4 vs. 10.1 +/- 1.2 mm, p < 0.001) and relative wall thickness (0.44 +/- 0.06 vs. 0.39 +/- 0.06, p < 0.01) as well as LV mass index (138 +/- 23 vs. 120 +/- 13 g/m2, p < 0.001) than those with the G-allele. Confounding factors (i.e., body mass index and surface area, plasma angiotensin II, sodium excretion, systolic and diastolic ambulatory blood pressure) were similar between the two genotypes. In normotensive subjects, relative wall thickness (0.36 +/- 0.05 vs. 0.35 +/- 0.05) and LV mass index (115 +/- 21 vs. 112 +/- 17 g/m2) were nearly identical across the two genotypes, with similar confounding variables. CONCLUSIONS: Our data indicate that the X-chromosomal located +1675 G/A-polymorphism of the AT2-R gene is associated with LV structure in young male humans with early structural changes of the heart due to arterial hypertension.

Aldosterone synthase (CYP11B2) -344 C/T polymorphism is associated with left ventricular structure in human arterial hypertension.

OBJECTIVES: This study examined the association between the -344 C/T polymorphism of the human aldosterone synthase promoter and left ventricular structure in arterial hypertension. BACKGROUND: Because of conflicting results from different studies, the mechanism of such an association, if any, has not been determined. METHODS: We examined the aldosterone synthase promoter genotype in 120 young (age: 26 +/- 3 years) male, white subjects with normal or mildly elevated blood pressure. Left ventricular structural parameters and urinary sodium excretion over 24 h before and after additional oral sodium load (6 g/day over 1 week) were determined. RESULTS: Hypertensive subjects with the CC genotype had a greater left ventricular end-diastolic diameter but smaller relative wall thickness than those with the TT genotype (54 +/- 2 vs. 50 +/- 4 mm, and 0.37 +/- 0.07 vs. 0.44 +/- 0.06 mm, respectively; p < 0.05). Hypertensive subjects with the TT genotype (n = 15) had a greater increase in urinary sodium excretion after oral sodium load than those with the CC genotype (n = 11) (135 +/- 95 vs. 24 +/- 133 mmol/liter/day; p < 0.05). Serum aldosterone levels were found to be decreased after oral sodium load in hypertensive subjects with the TT and CT genotypes only (-37 +/- 45 and -38 +/- 51 pg/ml, respectively; all p < 0.01) but not in those with the CC genotype (-12 +/- 30 pg/ml, n.s.). Such differences were not found in normotensive subjects. CONCLUSIONS: Hypertensive subjects with the -344 CC genotype of the aldosterone synthase promoter are characterized by a pattern of early eccentric left ventricular hypertrophy. Differences in renal sodium handling across the genotypes might contribute to this finding.

Rapid improvement of nitric oxide bioavailability after lipid-lowering therapy with cerivastatin within two weeks.

OBJECTIVES: We investigated whether improvement of endothelial dysfunction in hypercholesterolemia can be achieved with short-term lipid-lowering therapy. BACKGROUND: Impaired endothelium-dependent vasodilation plays a pivotal role in the pathogenesis of atherosclerosis and acute coronary syndromes. METHODS: In a randomized, double-blind, placebo-controlled trial, we studied 37 patients (52 +/- 11 yrs) with low density lipoprotein cholesterol > or = 160 mg/dl (196 +/- 44 mg/dl) randomly assigned to either cerivastatin (0.4 mg/d) or placebo. Endothelium-dependent vasodilation of the forearm vasculature was measured by plethysmography and intra-arterial infusion of acetylcholine (ACh 12, 48 microg/min) and endothelium-independent vasodilation by intra-arterial infusion of nitroprusside (3.2, 12.8 microg/min). RESULTS: Low density lipoprotein cholesterol decreased after two weeks of treatment (cerivastatin -33 +/- 4% vs. placebo + 2 +/- 4%, x +/- SEM, p < 0.001). Endothelium-dependent vasodilation improved after two weeks of therapy with cerivastatin compared with baseline (ACh 12 microg/min: + 22.3 +/- 5.2 vs. + 11.2 +/- 1.9 ml/min/100 ml, p < 0.01; ACh 48 microg/min: +31.2 +/- 6.3 vs. +19.1 +/- 3.1 ml/min/100 ml, p < 0.05). In contrast, changes in forearm blood flow to ACh were similar before and after therapy in the placebo group (ACh 12 microg/min: + 12.9 +/- 3.6 vs. + 9.0 +/- 1.9 ml/min/100 ml, NS; ACh 48 microg/min: +20.7 +/- 3.7 vs. 19.4 +/- 2.9 ml/min/100 ml, NS). Endothelium-dependent vasodilation improved in comparison with placebo (ACh 48 microg/min: +203 +/- 85% [cerivastatin] vs. -26 +/- 71% [placebo], p < 0.05). This improvement in endothelium-dependent vasodilation was no longer observed when the nitric oxide-synthase inhibitor N(G)-monomethyl-L-arginine was coinfused (ACh 48 microg/min + N(G)-monomethyl-L-arginine 4 micromol/min -48 +/- 85% [cerivastatin]). CONCLUSIONS: Short-term lipid-lowering therapy with cerivastatin can improve endothelial function and NO bioavailability after two weeks in patients with hypercholesterolemia.