RNA Interference With Zilebesiran for Mild to Moderate Hypertension: The KARDIA-1 Randomized Clinical Trial

Importance

Angiotensinogen is the most upstream precursor of the renin-angiotensin-aldosterone system, a key pathway in blood pressure (BP) regulation. Zilebesiran, an investigational RNA interference therapeutic, targets hepatic angiotensinogen synthesis.

Objective

To evaluate antihypertensive efficacy and safety of different zilebesiran dosing regimens.

Design, Setting, and Participants

This phase 2, randomized, double-blind, dose-ranging study of zilebesiran vs placebo was performed at 78 sites across 4 countries. Screening initiation occurred in July 2021 and the last patient visit of the 6-month study occurred in June 2023. Adults with mild to moderate hypertension, defined as daytime mean ambulatory systolic BP (SBP) of 135 to 160 mm Hg following antihypertensive washout, were randomized.

Interventions

Randomization to 1 of 4 subcutaneous zilebesiran regimens (150, 300, or 600 mg once every 6 months or 300 mg once every 3 months) or placebo (once every 3 months) for 6 months.

Main Outcomes and Measures

The primary end point was between-group difference in least-squares mean (LSM) change from baseline to month 3 in 24-hour mean ambulatory SBP.

Results

Of 394 randomized patients, 377 (302 receiving zilebesiran and 75 receiving placebo) comprised the full analysis set (93 Black patients [24.7%]; 167 [44.3%] women; mean [SD] age, 57 [11] years). At 3 months, 24-hour mean ambulatory SBP changes from baseline were -7.3 mm Hg (95% CI, -10.3 to -4.4) with zilebesiran, 150 mg, once every 6 months; -10.0 mm Hg (95% CI, -12.0 to -7.9) with zilebesiran, 300 mg, once every 3 months or every 6 months; -8.9 mm Hg (95% CI, -11.9 to -6.0) with zilebesiran, 600 mg, once every 6 months; and 6.8 mm Hg (95% CI, 3.6-9.9) with placebo. LSM differences vs placebo in change from baseline to month 3 were -14.1 mm Hg (95% CI, -19.2 to -9.0; P < .001) with zilebesiran, 150 mg, once every 6 months; -16.7 mm Hg (95% CI, -21.2 to -12.3; P < .001) with zilebesiran, 300 mg, once every 3 months or every 6 months; and -15.7 mm Hg (95% CI, -20.8 to -10.6; P < .001) with zilebesiran, 600 mg, once every 6 months. Over 6 months, 60.9% of patients receiving zilebesiran had adverse events vs 50.7% patients receiving placebo and 3.6% had serious adverse events vs 6.7% receiving placebo. Nonserious drug-related adverse events occurred in 16.9% of zilebesiran-treated patients (principally injection site reactions and mild hyperkalemia) and 8.0% of placebo-treated patients.

Conclusions and Relevance

In adults with mild to moderate hypertension, treatment with zilebesiran across a range of doses at 3-month or 6-month intervals significantly reduced 24-hour mean ambulatory SBP at month 3.

Trial Registration

ClinicalTrials.gov Identifier: NCT04936035.

The burden of nonalcoholic steatohepatitis (NASH) in the United States

BACKGROUND

There is limited data on the comparative economic and humanistic burden of non-alcoholic steatohepatitis (NASH) in the United States. The objective was to examine the burden of disease comparing NASH to a representative sample of the general population and separately to a type 2 diabetes mellitus (T2DM) cohort by assessing health-related quality of life (HRQoL) measures, healthcare resource use (HRU) and work productivity and activity impairment (WPAI).

METHODS

Data came from the 2016 National Health and Wellness Survey, a nationally representative patient-reported outcomes survey conducted in the United States. Respondents with physician-diagnosed NASH, physician-diagnosed T2DM, and respondents from the general population were compared. Humanistic burden was examined with mental (MCS) and physical (PCS) component summary scores from the Short-Form (SF)-36v2, concomitant diagnosis of anxiety, depression, and sleep difficulties. Economic burden was analysed based on healthcare professional (HCP) and emergency room (ER) visits, hospitalizations in the past six months; absenteeism, presenteeism, overall work impairment, and activity impairment scores on WPAI questionnaire. Bivariate and multivariable analysis were conducted for each outcome and matched comparative group.

RESULTS

After adjusting for baseline demographics and characteristics, NASH (N = 136) compared to the matched general population cohort (N = 544), reported significantly lower (worse) mental (MCS 43.19 vs. 46.22, p = 0.010) and physical (PCS 42.04 vs. 47.10, p < 0.001) status, higher % with anxiety (37.5% vs 25.5%, p = 0.006) and depression (43.4% vs 30.1%, p = 0.004), more HCP visits (8.43 vs. 5.17), ER visits (0.73 vs. 0.38), and hospitalizations (0.43 vs. 0.2) all p's < 0.05, and higher WPAI scores (e.g. overall work impairment 39.64% vs. 26.19%, p = 0.011). NASH cohort did not differ from matched T2DM cohort (N = 272) on mental or work-related WPAI scores, but had significantly worse physical status (PCS 40.52 vs. 44.58, p = 0.001), higher % with anxiety (39.9% vs 27.8%, p = 0.043), more HCP visits (8.63 vs. 5.68, p = 0.003) and greater activity impairment (47.14% vs. 36.07%, p = 0.010).

CONCLUSION

This real-world study suggests that burden of disease is higher for all outcomes assessed among NASH compared to matched general controls. When comparing to T2DM, NASH cohort has comparable mental and work-related impairment but worse physical status, daily activities impairment and more HRU.

Cardiovascular outcomes at recommended blood pressure targets in middle-aged and elderly patients with type 2 diabetes mellitus compared to all middle-aged and elderly hypertensive study patients with high cardiovascular risk

PURPOSE

Event-based clinical outcome trials have shown limited evidence to support guidelines recommendations to lower blood pressure (BP) to <130/80 mmHg in middle-aged and elderly hypertensive patients with diabetes mellitus or with general high cardiovascular (CV) risk. We addressed this issue by post-hoc analysing the risk of CV events in patients who participated in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial and compared the hypertensive patients with type 2 diabetes mellitus with all high-risk hypertensive patients.

MATERIALS AND METHODS

Patients were divided into 4 groups according to the proportion of on-treatment visits before the occurrence of an event (<25% to ≥75%) in which BP was reduced to <140/90 or <130/80 mmHg. Patients with diabetes mellitus (n = 5250) were compared with the entire VALUE population with high CV risk (n = 15,245).

RESULTS

After adjustments for baseline differences between groups, a reduction in the proportion of visits in which BP was reduced to <140/90 mmHg, but not to <130/80 mmHg, was accompanied by a progressive increase in the risk of CV morbidity and mortality as well as stroke, myocardial infarction and heart failure in both diabetes mellitus and in all high-risk patients. Target BP <130/80 mmHg reduced stroke risk in the main population but not in the diabetes mellitus patients. Patients with diabetes mellitus had higher event rates for the primary cardiac endpoint and all-cause mortality driven by a higher rate of heart failure.

CONCLUSION

In the high-risk hypertensive patients of the VALUE trial achieving more frequently BP <140/90 mmHg, but not <130/80 mmHg, showed principally the same protective effect on overall and cause-specific cardiovascular outcomes in patients with diabetes mellitus and in the general high-risk hypertensive population.

Cardiovascular outcomes at recommended blood pressure targets in middle-aged and elderly patients with type 2 diabetes mellitus and hypertension

PURPOSE

Available data of event-based clinical outcomes trials show that little evidence supports the guidelines recommendations to lower blood pressure (BP) to <130/80 mmHg in middle-aged and elderly people with type 2 diabetes mellitus and hypertension. We addressed this issue by post-hoc analysing the risk of cardiovascular (CV) events in mostly elderly high-risk hypertensive patients with type 2 diabetes mellitus participating in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial.

MATERIAL AND METHODS

Patients (n = 5250) were divided into 4 groups according to the proportion of on-treatment visits before the occurrence of an event (<25% to ≥ 75%) in which BP was reduced to <140/90 or <130/80 mmHg.

RESULTS

After adjustment for baseline demographic differences between groups, a reduction in the proportion of visits in which BP achieved <140/90 mmHg accompanied a progressive increase in the risk of CV mortality and morbidity as well as of cause-specific events such as stroke, myocardial infarction and heart failure. A progressive reduction in the proportion of visits in which BP was reduced <130/80 mmHg did not have any effect on CV risks.

CONCLUSION

In mostly elderly high-risk hypertensive patients with type 2 diabetes mellitus participating in the VALUE trial, achieving more frequently BP <140/90 mmHg showed a marked protective effect on overall and all cause-specific cardiovascular outcomes. This was not the case for a more frequent achievement of the more intensive BP target, i.e. <130/80 mmHg.

The burden of non-alcoholic steatohepatitis (NASH) among patients from Europe: A real-world patient-reported outcomes study

Data on the economic and humanistic burden of non-alcoholic steatohepatitis (NASH) are scarce. This study assessed the comparative burden of NASH, relative to a representative sample from the general population and a type 2 diabetes mellitus (T2DM) cohort, in terms of health-related quality of life, work productivity and activity impairment (WPAI), and healthcare resource use.

Methods

Data across 5 European countries came from the 2016 National Health and Wellness Survey, a nationally representative patient-reported outcomes survey. Outcomes included mental (MCS) and physical (PCS) component scores from the Short-Form (SF)-36v2, WPAI scores, self-reported physician diagnosis of sleep difficulties, anxiety, and depression, and healthcare resource use: healthcare professional visits, hospital visits, and emergency room visits in the previous 6 months. Bivariate and multivariable analyses were conducted for each outcome and comparative group.

Results

After adjusting for matching criteria and covariates, patients with NASH (n = 184) reported significantly worse health-related quality of life, worse WPAI scores, and more healthcare resource use than the general population (n = 736) (MCS 39.22 vs. 45.16, PCS 42.84 vs. 47.76; overall work impairment 49.15% vs. 30.77%, healthcare professional visits 10.73 vs. 6.01, emergency room visits 0.57 vs. 0.22, hospitalizations 0.47 vs. 0.17, p ≪0.05 for all). Patients with NASH did not differ from patients with T2DM (n = 368) on PCS and WPAI scores, suggesting a similar impairment on work and daily activities, but did report significantly worse mental status (MCS 39.64 vs. 43.64, p ≪0.05) and more healthcare resource use than those with T2DM (healthcare professional visits 10.85 vs. 7.86, emergency room visits 0.65 vs. 0.23, hospitalizations 0.39 vs. 0.19, p ≪0.05 for all).

Conclusions

These findings suggest that the burden of NASH may be underestimated, highlighting the unmet needs of patients with NASH.

Lay summary

These findings show that patients with non-alcoholic steatohepatitis (NASH) experience a significant burden of illness, in terms of health-related quality of life, work productivity and activity impairment, and healthcare resource use. As there is currently no approved treatment for NASH, these findings highlight the unmet medical need of patients with NASH.

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Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease.

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NASH imposes a significant humanistic and economic burden on individuals and society.

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NASH impairs health-related quality of life, work productivity and activity, while increasing healthcare resource use.

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This study highlights the unmet need of patients with NASH in the absence of any approved treatment.

Determination of volume-dependent respiratory system mechanics in mechanically ventilated patients using the new SLICE method

In patients mechanically ventilated for severe respiratory failure, respiratory system mechanics are non-linear, i.e., volume-dependent. We present a new computer-based multipoint method for simultaneously determining volume-dependent dynamic compliance and resistance. Our method is based on continuously determined tracheal pressure (Ptrach). Tidal volume is subdivided into six volume slices of equal size. One compliance value (intrinsic PEEP considered) and one resistance value are determined for each volume slice by applying of the least-squares-fit (LSF) analysis based on the linear RC-model; we therefore call this the SLICE method. The method gives the course of dynamic compliance and resistance within the tidal volume. The method was evaluated using physical models of the respiratory system with linear and non-linear passive mechanical properties. The relative error of the method is smaller than ±5%. The method needs no special ventilatory pattern. Using data from 14 patients mechanically ventilated for adult respiratory distress syndrome (ARDS) we found a very good correspondence between the measured end-inspiratory airway pressure (Paw,Ie) and the end-inspiratory alveolar pressure (Palv,Ie) calculated from the dynamic compliance values determined with the SLICE method (Palv,Ie = 1.02 * Paw,Ie + 0.097; r2 = 0.977). The SLICE method allows continuous monitoring of non-linear pulmonary mechanics on a breath-by-breath basis at the bedside.

Comparison of benazepril plus amlodipine or hydrochlorothiazide in high-risk patients with hypertension and coronary artery disease

Combination therapy with benazepril 40 mg and amlodipine 10 mg (B+A) has been shown to be more effective than benazepril 40 mg and hydrochlorothiazide (HCTZ) 25 mg (B+H) in reducing cardiovascular (CV) events in high-risk patients with stage 2 hypertension with similar blood pressure reductions. In the present post hoc analysis, we evaluated whether B+A is more effective than B+H for reducing CV events in patients with known coronary artery disease (CAD) at baseline in a subgroup analysis of the Avoiding Cardiovascular events through COMbination therapy in Patients LIving with Systolic Hypertension (ACCOMPLISH) study. The main trial randomized 11,506 patients. Of those, 5,744 received B+A and 5,762 received B+H. Of the 11,506 patients, 5,314 (46%) were classified as having CAD at baseline. The mean patient follow-up period was 35.7 months for the B+A group and 35.6 months for the B+H group. The primary end point was the interval to the first event of composite CV morbidity and mortality. At baseline, significant differences were present between the 5,314 with CAD and the 6,192 without CAD. The patients with CAD had a lower systolic blood pressure and heart rate, a lower incidence of diabetes, and greater incidence of dyslipidemia. However, no baseline differences were found between the randomized B+A and B+H groups. In the patients with CAD, an 18% reduction occurred in the hazard ratio for CV events (primary end point) with B+A versus B+H (p = 0.0016). In a prespecified secondary analysis of the composite end point, including only CV death, myocardial infarction, and stroke, the hazard ratio in the patients with CAD was reduced by 25% (p = 0.0033) in the B+A group compared with the B+H group. B+A was more effective than B+H at comparable blood pressure reductions for reducing CV events in patients, regardless of the presence of CAD. In conclusion, our findings suggest that the combination of B+A should be preferentially used for older patients with high-risk, stage 2 hypertension.

Effects of body size and hypertension treatments on cardiovascular event rates: subanalysis of the ACCOMPLISH randomised controlled trial

BACKGROUND

In previous clinical trials in high-risk hypertensive patients, paradoxically higher cardiovascular event rates have been reported in patients of normal weight compared with obese individuals. As a prespecified analysis of the Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension (ACCOMPLISH) trial, we aimed to investigate whether the type of hypertension treatment affects patients' cardiovascular outcomes according to their body size.

METHODS

On the basis of body-mass index (BMI), we divided the full ACCOMPLISH cohort into obese (BMI ≥30, n=5709), overweight (≥25 to <30, n=4157), or normal weight (<25, n=1616) categories. The ACCOMPLISH cohort had already been randomised to treatment with single-pill combinations of either benazepril and hydrochlorothiazide or benazepril and amlodipine. We compared event rates (adjusted for age, sex, diabetes, previous cardiovascular events, stroke, or chronic kidney disease) for the primary endpoint of cardiovascular death or non-fatal myocardial infarction or stroke. The analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00170950.

FINDINGS

In patients allocated benazepril and hydrochlorothiazide, the primary endpoint (per 1000 patient-years) was 30·7 in normal weight, 21·9 in overweight, and 18·2 in obese patients (overall p=0·0034). However, in those allocated benazepril and amlodipine, the primary endpoint did not differ between the three BMI groups (18·2, 16·9, and 16·5, respectively; overall p=0·9721). In obese individuals, primary event rates were similar with both benazepril and hydrochlorothiazide and benazepril and amlodipine, but rates were significantly lower with benazepril and amlodipine in overweight patients (hazard ratio 0·76, 95% CI 0·59-0·94; p=0·0369) and those of normal weight (0·57, 0·39-0·84; p=0·0037).

INTERPRETATION

Hypertension in normal weight and obese patients might be mediated by different mechanisms. Thiazide-based treatment gives less cardiovascular protection in normal weight than obese patients, but amlodipine-based therapy is equally effective across BMI subgroups and thus offers superior cardiovascular protection in non-obese hypertension.

FUNDING

Novartis Pharmaceuticals.

Home and clinic blood pressure responses in elderly individuals with systolic hypertension

Home blood pressure (BP) monitoring may enhance assessment of BP control. In this 16-week study, men and women 70 years or older with systolic BP between 150 and 200 mm Hg were randomized to receive valsartan/hydrochlorothiazide (V/HCTZ) 160/12.5 mg (n = 128), HCTZ 12.5 mg (n = 128), or V 160 mg (n = 128) for 4 weeks. Participants whose BP was 140/90 mm Hg or higher at weeks 4, 8, or 12 were uptitrated to a maximum of V/HCTZ 320/25 mg. Participants were evaluated by home BP monitoring using an automated device weekly before taking daily study medication (n = 301). Baseline BP ± SD for clinic (165.5 ± 11.8/85.1 ± 9.5 mm Hg) was approximately 3/1 mm Hg greater than home readings (162.5 ± 15.8/84.3 ± 10.2 mm Hg). Reductions in BP ± SEM at week 4 were similar for clinic (12.6 ± 1.0/4.7 ± 0.5 mm Hg) and home (10.9 ± 1.1/3.8 ± 0.5 mm Hg) readings (P = .25/P = .23; clinic versus home); differences between V/HCTZ and HCTZ or V were also similar for both home and clinic readings and results by either technique correlated significantly (P < .0001). Home BP measurements confirm that treatment initiated with V/HCTZ versus monotherapy resulted in greater antihypertensive efficacy. Home BP monitoring, if done with proper technique, provides a reliable indicator of BP control in elderly patients and may help guide drug dosing and titration.

Usefulness of heart rate to predict cardiac events in treated patients with high-risk systemic hypertension

A high heart rate (HR) predicts future cardiovascular events. We explored the predictive value of HR in patients with high-risk hypertension and examined whether blood pressure reduction modifies this association. The participants were 15,193 patients with hypertension enrolled in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial and followed up for 5 years. The HR was assessed from electrocardiographic recordings obtained annually throughout the study period. The primary end point was the interval to cardiac events. After adjustment for confounders, the hazard ratio of the composite cardiac primary end point for a 10-beats/min of the baseline HR increment was 1.16 (95% confidence interval 1.12 to 1.20). Compared to the lowest HR quintile, the adjusted hazard ratio in the highest quintile was 1.73 (95% confidence interval 1.46 to 2.04). Compared to the pooled lower quintiles of baseline HR, the annual incidence of primary end point in the top baseline quintile was greater in each of the 5 study years (all p <0.05). The adjusted hazard ratio for the primary end point in the highest in-trial HR heart rate quintile versus the lowest quintile was 1.53 (95% confidence interval 1.26 to 1.85). The incidence of primary end points in the highest in-trial HR group compared to the pooled 4 lower quintiles was 53% greater in patients with well-controlled blood pressure (p <0.001) and 34% greater in those with uncontrolled blood pressure (p = 0.002). In conclusion, an increased HR is a long-term predictor of cardiovascular events in patients with high-risk hypertension. This effect was not modified by good blood pressure control. It is not yet known whether a therapeutic reduction of HR would improve cardiovascular prognosis.

Predictors of systolic BP <140 mmHg and systolic BP level by randomly assigned treatment group (benazepril plus amlodipine or hydrochlorothiazide) in the ACCOMPLISH Study

BACKGROUND

The ACCOMPLISH Trial investigated intensive antihypertensive combination treatment with benazepril + amlodipine (B+A) or benazepril + hydrochlorothiazide (B+H) on cardiovascular outcomes in patients with systolic hypertension. We analyzed the baseline predictors of achieving a systolic blood pressure (SBP) <140 mmHg and achieved SBP level by the end of 12 months in both treatment groups.

METHODS

Baseline and 12-month SBP was available in 10,506 patients, of whom 6250 had diabetes. Univariate and multivariate logistic regression models were used for SBP control at 12 months and multivariable regression models were used for the prediction of SBP at 12 months. A stepwise procedure was used to select significant (p < 0.001) predictors in multivariate analyses.

RESULTS

Mean (± SD) BP fell from 145.4/80.1 (± 18.3/10.7) mmHg at randomization to 132.8/74.7 (± 16.0/9.6) mmHg at 12 months. The main baseline predictors of SBP control <140 mmHg were region (USA >Nordic region) and Caucasian ethnicity in both randomization arms. A higher diastolic BP and the use of lipid lowering agents indicated favorable effects in the B+H arm only. The predictors of uncontrolled SBP were: (i) higher baseline SBP values, (ii) higher number of previous antihypertensive medications in both arms, (iii) the previous use of insulin in the B+A arm, and (iv) pre-trial calcium channel blocker (CCB) use in the B+H arm. Additionally, pre-trial use of thiazides and electrocardiogram (ECG)-left ventricular hypertrophy (LVH) at baseline predicted higher, and smoking lower absolute SBP in the B+A arm and the use of thiazides and proteinuria a higher SBP in the B+H arm.

CONCLUSION

Irrespective of treatment, patients in the USA and Caucasians achieved better SBP control, whereas higher baseline SBP and more previous antihypertensive medications indicated less control. Concomitant use of lipid lowering treatment indicated a better SBP control in the benazepril + hydrochlorothiazide arm. Lastly, insulin use and ECG-LVH in the benazepril + amlodipine arm and proteinuria in the benazepril + hydrochlorothiazide arm indicated poor control.

24-Hour ambulatory blood pressure response to combination valsartan/hydrochlorothiazide and amlodipine/hydrochlorothiazide in stage 2 hypertension by ethnicity: the EVALUATE study

Several studies reported racial/ethnic differences in blood pressure (BP) response to antihypertensive monotherapy. In a 10-week study of stage 2 hypertension, 320/25 mg valsartan/hydrochlorothiazide (HCTZ) reduced ambulatory BP (ABP) significantly more effectively than 10/25 mg amlodipine/HCTZ. Results (post hoc analysis) are described in Caucasians (n=256), African Americans (n=79), and Hispanics (n=86). Compared with clinic-measured BP (no significant treatment-group differences in ethnic subgroups), least-squares mean reductions from baseline to week 10 in mean ambulatory systolic BP (MASBP) and mean ambulatory diastolic BP (MADBP) favored valsartan/HCTZ over amlodipine/HCTZ in Caucasians (-21.9/-12.7 mm Hg vs -17.6/-9.5 mm Hg; P=.0004/P<.0001). No treatment-group differences in MASBP/MADBP were observed in African Americans (-17.3/-10.6 vs -17.9/-9.5; P=.76/P=.40) or Hispanics (-17.9/-9.7 vs -14.2/-7.2; P=.20/P=.17). Based on ABP monitoring, valsartan/HCTZ is more effective than amlodipine/HCTZ in lowering ABP in Caucasians. In African Americans and Hispanics, both regimens are similarly effective.

Valsartan: more than a decade of experience

Valsartan is a nonpeptide angiotensin receptor antagonist that selectively blocks the binding of angiotensin II to the angiotensin II type 1 receptor. The efficacy, tolerability and safety of valsartan have been demonstrated in large-scale studies in hypertension, heart failure (HF) and post-myocardial infarction (MI). This review focuses on what was learned from the valsartan clinical research programme and other comparative trials published from 1997 to the present. Many studies have demonstrated the efficacy of valsartan in lowering blood pressure (BP) in a variety of patient populations (including elderly, women, children, obese patients, patients with diabetes mellitus, patients with chronic kidney disease [CKD], patients at high risk of cardiovascular [CV] disease, African Americans, Hispanic Americans and Asians) and in improving outcomes in CV disease and CKD. In hypertension, valsartan exhibits dose-dependent efficacy in reducing both systolic and diastolic BP over the once-daily dose range of 80-320 mg; doses as high as 640 mg/day have been studied and found to be efficacious and safe. BP control can be enhanced with a more consistent 24-hour BP-lowering profile by using single-pill, fixed-dose combination therapy with valsartan plus hydrochlorothiazide (HCTZ). The cardioprotective benefits of valsartan have been demonstrated in large-scale outcome trials and include significant reductions in CV morbidity and mortality in HF, following MI, and in patients with co-morbid hypertension and coronary artery disease and/or HF; reductions in HF hospitalizations; and reductions in the incidence of stroke. The magnitude of these effects is comparable with that demonstrated with angiotensin-converting enzyme (ACE) inhibitors; however, valsartan has a more favourable tolerability profile, with a significantly lower incidence of cough and only rare reports of angio-oedema, both class effects of ACE inhibitor use. Consistent with its angiotensin receptor-blocking effects, valsartan also reduces circulating levels of biochemical markers that are associated with angiotensin II-mediated endothelial dysfunction and CV risk (e.g. high-sensitivity C-reactive protein or oxidized low-density lipoprotein). Improvements in CKD with valsartan include statistically and clinically meaningful reductions in urinary albumin and protein excretion in patients with type 2 diabetes and in nondiabetic patients with CKD. In short-term studies, valsartan has improved or stabilized various indices of metabolic function in at-risk patients, including those with co-morbid hypertension, obesity and/or metabolic syndrome. Because of this, valsartan is being prospectively investigated for its ability to reduce the incidence of new-onset diabetes and provide cardioprotection in patients with impaired glucose tolerance. Valsartan and valsartan/HCTZ are well tolerated. In clinical trials, adverse events during valsartan treatment were similar to those occurring with placebo. The combination of valsartan/HCTZ was better tolerated than HCTZ alone. Valsartan is administered once daily for hypertension; doses are usually taken upon awakening. In patients with HF or MI, valsartan is administered twice daily.

Randomized study to compare valsartan +/- HCTZ versus amlodipine +/- HCTZ strategies to maximize blood pressure control

OBJECTIVE

Delays in achieving blood pressure (BP) control may increase morbidity and mortality in patients with hypertension. Thus, deciding which antihypertensive agent to use and at what dosage, in addition to determining when to initiate combination therapy and which agents to combine, is important for achieving BP control.

METHODS

This randomized, double-blind, 14-week study was conducted to compare the efficacy and tolerability of various doses of valsartan +/- hydrochlorothiazide (HCTZ) versus amlodipine +/- HCTZ for maximizing BP control in 1,285 patients with uncontrolled hypertension. Patients with stage 1 hypertension and naïve to antihypertensive therapy (33.9%) started valsartan 160 mg or amlodipine 5 mg. Treatment-naïve patients with stage 2 hypertension (13.5%) or those uncontrolled on current antihypertensive monotherapy (52.6%) started valsartan 160 mg/HCTZ 12.5 mg or amlodipine 10 mg. At weeks 4, 8, and 11, patients not achieving BP control were up-titrated (maximum: valsartan 320 mg/HCTZ 25 mg, amlodipine 10 mg/HCTZ 25 mg).

RESULTS

At study end, 78.8% of patients on valsartan +/- HCTZ were controlled (BP <140/90 mmHg) and still on study medication versus 67.8% on amlodipine +/- HCTZ (P < 0.0001). Amlodipine-treated patients had a higher incidence of peripheral edema (22.4% vs 2.2%) and associated discontinuations (7.3% vs <1%). Initiating therapy earlier with valsartan/HCTZ, rather than titrating monotherapy to its maximum dose before adding a second agent, was superior to amlodipine monotherapy or amlodipine +/- HCTZ for achieving BP control, and avoided excessive treatment adjustments and maintained tolerability.

Achieving BP goals with valsartan and HCTZ alone and in combination: pooled analysis of two randomized, double-blind, placebo-controlled studies

BACKGROUND

Most patients with hypertension will require combination therapy to achieve blood pressure (BP) goals, especially the elderly, obese, or those with stage 2 hypertension.

OBJECTIVE

To assess BP response and time to achieve BP goals in a diverse population of hypertensive patients treated with hydrochlorothiazide, valsartan, or a combination.

METHODS

For this secondary post-hoc analysis, data were pooled from two similar randomized, double-blind, 8-week trials that evaluated hydrochlorothiazide (12.5-25 mg) and valsartan (160 mg) monotherapies, their combination (160/12.5 mg), and placebo. Subgroups were defined by age, hypertension severity, and obesity. Adults with diastolic BP > or =95 and < or =115 mmHg were included. Goal rates were estimated from a logistic model with treatment, study, age group, race, and baseline body mass index as factors and baseline diastolic BP as a covariate. Kaplan-Meier estimates were used to calculate the time to achieve BP goals.

MAIN OUTCOME MEASURES

Efficacy variables were reductions from baseline to study end in systolic BP and diastolic BP, rates of achieving BP goals (<140/90 mmHg), and time to achieve BP goals. Adverse events were also reported for the pooled trials.

RESULTS

BP reductions at study end and goal achievement rates were greater with combination therapy (-20/15 mmHg and 72%, respectively) than with either monotherapy (valsartan 160 mg: -14/11 mmHg, 61%; hydrochlorothiazide 25 mg: -14/10 mmHg, 50%) for the overall population (N=1313) and in patient subgroups. Patients treated with initial combination therapy reached goal in 27-56% of the time needed for those treated with monotherapy. Combination therapy was well tolerated and was associated with a decreased incidence of hypokalemia compared with hydrochlorothiazide monotherapy.

CONCLUSIONS

Compared with monotherapy, combination therapy resulted in greater reductions in BP and achievement of goal BP in a shorter period of time. Although interpretation of this study is subject to the limitations associated with any post-hoc analysis, the results suggest that initiating treatment with combination therapy may be considered for expedient and effective BP control.

Effects of mechanical unloading/loading on respiratory loop gain and periodic breathing in man

We investigated the effect of mechanical unloading and loading on Cheyne-Stokes respiration (CSR) in seven intubated patients with preexisting CSR. For mechanical loading patients had to breathe against the resistance of the endotracheal tube. For mechanical unloading patients were supported with a volume-proportional pressure support in the proportional assist ventilation (PAV) mode whilst the flow-dependent (nonlinear) endotracheal tube resistance was continuously compensated for by means of the automatic tube compensation (ATC) mode. Mechanical unloading aggravated CSR as revealed by a prolongation of apnea time and by an increase in the so-called strength index whereas mechanical loading shortened apnea time and decreased strength index. To test whether the observed changes are caused by the effect of mechanical unloading/loading on respiratory loop gain (relationship between minute ventilation and arterial CO2 tension), the response of respiratory loop gain on mechanical unloading/loading was determined in five healthy subjects (without CSR). In each subject, mechanical unloading increased respiratory loop gain whereas mechanical loading decreased it.

Respiratory comfort of automatic tube compensation and inspiratory pressure support in conscious humans

OBJECTIVE

To compare the new mode of ventilatory support, which we call automatic tube compensation (ATC), with inspiratory pressure support (IPS) with respect to perception of respiratory comfort. ATC unloads the resistance of the endotracheal tube (ETT) in inspiration by increasing the airway pressure, and in expiration by decreasing the airway pressure according to the non-linear pressure-flow relationship of the ETT.

DESIGN

Prospective randomized single blind cross-over study.

SETTING

Laboratory of the Section of Experimental Anaesthesiology (Clinic of Anaesthesiology; University of Freiburg).

SUBJECTS

Ten healthy volunteers.

INTERVENTIONS

The subjects breathed spontaneously through an ETT of 7.5 mm i.d. Three different ventilatory modes, each with a PEEP of 5 cmH2O, were presented in random order using the Dräger Evita 2 ventilator with prototype software: (1) IPS (10 cmH2O, 1 s ramp), (2) inspiratory ATC (ATC-in), (3) inspiratory and expiratory ATC (ATC-in-ex).

MEASUREMENTS AND MAIN RESULTS

Immediately following a mode transition, the volunteers answered with a hand sign to show how they perceived the new mode compared with the preceding mode in terms of gain or loss in subjective respiratory comfort: "better", "unchanged" or "worse". Inspiration and expiration were investigated separately analyzing 60 mode transitions each. Flow rates were continuously measured. The transition from IPS to either type of ATC was perceived positively, i.e. as increased comfort, whereas the opposite transition from ATC to IPS was perceived negatively, i.e. as decreased comfort. The transition from ATC-in to ATC-in-ex was perceived positively whereas the opposite mode transition was perceived negatively in expiration only. Tidal volume was 1220 +/- 404 ml during IPS and 1017 +/- 362 ml during ATC. The inspiratory peak flow rate was 959 +/- 78 ml/s during IPS and 1048 +/- 197 ml/s during ATC.

CONCLUSIONS

ATC provides an increase in respiratory comfort compared with IPS. The predominant cause for respiratory discomfort in the IPS mode seems to be lung over-inflation.

Breathing pattern and additional work of breathing in spontaneously breathing patients with different ventilatory demands during inspiratory pressure support and automatic tube compensation

OBJECTIVE

We designed a new ventilatory mode to support spontaneously breathing, intubated patients and to improve weaning from mechanical ventilation. This mode, named Automatic Tube Compensation (ATC), compensates for the flow-dependent pressure drop across the endotracheal tube (ETT) and controls tracheal pressure to a constant value. In this study, we compared ATC with conventional patient-triggered inspiratory pressure support (IPS).

DESIGN

A prospective, interventional study.

SETTING

A medical intensive care unit (ICU) and an ICU for heart and thoracic surgery in a university hospital.

PATIENTS

We investigated two groups of intubated, spontaneously breathing patients: ten postoperative patients without lung injury, who had a normal minute ventilation (VE) of 7.6 +/- 1.7 l/min, and six critically ill patients who showed increased ventilatory demand (VE = 16.8 +/- 3.0 l/ min).

INTERVENTIONS

We measured the breathing pattern [VE, tidal volume (VT), and respiratory rate (RR)] and additional work of breathing (WOBadd) due to ETT resistance and demand valve resistance. Measurements were performed under IPS of 5, 10, and 15 mbar and under ATC.

RESULTS

The response of VT, RR, and WOBadd to different ventilatory modes was different in both patient groups, whereas VE remained unchanged. In postoperative patients, ATC, IPS of 10 mbar, and IPS of 15 mbar were sufficient to compensate for WOBadd. In contrast, WOBadd under IPS was greatly increased in patients with increased ventilatory demand, and only ATC was able to compensate for WOBadd.

CONCLUSIONS

The breathing pattern response to IPS and ATC is different in patients with differing ventilatory demand. ATC, in contrast to IPS, is a suitable mode to compensate for WOBadd in patients with increased ventilatory demand. When WOBadd was avoided using ATC, the patients did not need additional pressure support.

Blood metabolite and catecholamine responses to prolonged exercise following either acute plasma volume expansion or short-term training

To determine the effect of acute plasma volume (PV) expansion on substrate utilization, blood metabolites and catecholamines to prolonged, moderate intensity cycle exercise, eight untrained men mean maximal oxygen uptake VO2max 4.10 (SEM 0.32) 1.min-1 were infused (10 ml.kg-1) with a 6% dextran (DEX) solution. These responses were also compared to those elicited using a short-term training (TR) protocol involving cycling for 90 to 120 min.day-1 at 60% VO2max for 3 consecutive days. In general DEX, which resulted in a calculated expansion of PV by 23.9% was without effect in modifying exercise oxygen uptake or the reduction in the respiratory exchange ratio (R) observed during prolonged exercise. In addition, the concentrations of blood glucose, glycerol, alanine and serum free fatty acids, although altered (P < 0.05) by exercise, were not altered by DEX. Blood lactate concentration was only higher (P < 0.05) at 30 min of exercise during DEX compared to the control. With the exception of blood lactate concentration, which was reduced (P < 0.05), TR did not change R or the concentrations of other blood metabolites. The concentrations of nonadrenaline and adrenaline, were depressed (P < 0.05) by DEX and TR at 60 and 90 min of exercise. These results would suggest that mechanisms as yet undefined can compensate for the estimated 10% reduction in arterial oxygen content mediated by acute PV expansion and enable prolonged exercise to be performed without adjustments in substrate selection and substrate mobilization.

[Added work of breathing, respiratory pattern and determination of ventilator weaning readiness in inspiratory pressure support and and automatic tube compensation]

We measured the ventilatory pattern and additional work of breathing (WOBadd) at three different levels of inspiratory pressure support [IPS 5, 10, 15 mbar above positive end-expiratory pressure (PEEP)] and in a new ventilatory mode, automatic tube compensation (ATC), in nine operative patients without lung injury nine patients ventilated for several following acute respiratory insufficiency (ARI). In ATC, endotracheal tube resistance is compensated automatically by means of closed-loop control of the calculated tracheal pressure. Pressure support in this mode, i.e. airway pressure above PEEP, is equal to the actual flow-dependent pressure drop across the endotracheal tube (ETT). Airway pressure rises at the beginning of inspiration and falls towards the end. As the tube resistance of ETT seriously hinders expiration and can cause desynchronization between ventilator and patient, airway pressure is reduced below PEEP during expiration in the same way as it is increased during inspiration. The result is a near-constant tracheal pressure at PEEP both during inspiration and during expiration. This mode could be best termed as "electronic extubation". The most striking difference between the postoperative patients and the ARI patients was their minute ventilation (17.8 +/- 1.85 l/min in ARI patients vs 7.3 +/- 3.1 l/min in the postoperative patients). In the postoperative patients augmentation of IPS from 5 to 15 mbar induced a steady increase in tidal volume (VT) and a consecutive decrease in respiratory rate (rr) compared with ATC (VTATC,postop = 463 +/- 78 ml; rrATC,postop = 16 +/- 4 min-1; VTIPS5.postop = 505 +/- 79 ml; rrIPS5,postop = 15 +/- 4 min-1; VTIPS10,postop = 562 +/- 86 ml; rrIPS15,postop = 14 +/- 4 min-1; VTIPS15.postop = 660 +/- 151 ml; rrTPS15,postop = 12 +/- 4 min-1), whereas the augmentation of IPS of 5 and 10 mbar in the ARI patients could not compensate for the increase in rr and the decrease in VT, after switching from ATC to IPS (VTATC,ARI 724 +/- 308 ml, rrATC,ARI = 24 +/- 6 min-1; VTIPS5,ARI = 649 +/- 315 ml; rrIPS5,ARI = 27 +/- 8 min-1; VTIPS10,ARI = 653 +/- 353 ml; rrIPS10,ARI = 25 +/- 8 min-1: Even IPS 15 was not able to reestablish VT at the values observed during ATC (VTIPS15,ARI = 680 +/- 312 ml). During ATC WOBadd was small in both postoperative and ARI patients (WOBadd,ATC,postop = 93 +/- 36 mJ/l, WOBadd,ATC,ARI = 116 +/- 72 mJ/l). In the postoperative patients, an inspiratory pressure support of 5 mbar was not sufficient to compensate WOBadd compared with ATC. However, IPS 10 and 15 mbar were able to compensate for WOBadd (WOBadd,ATC5.postop WOBadd,IPS5,postop = 189 +/- 77 mJ/l; WOBadd,IPS10,postop = 55 +/- 30 mJ/l; WOBadd,IPS15,postop = 21 +/- 11 mJ/l). In the ARI patients an IPS 5, 10 or 15 mbar was not sufficient to compensate for WOBadd (WOBadd,IPS 5,ARI = 1126 +/- 262 mJ/l; WOBadd,IPS 10,ARI 863 +/- 253 mJ/l; WOBadd,IPS15,ARI 763 +/- 298 mJ/l). Under ATC, WOBadd was only 15% of WOBadd under IPS of 15 mbar. All but two patients were successfully extubated after the investigation. These two patients were not extubated because they were dependent on an FIO2 > 0.5. Our results strongly indicate that ventilatory dependence in ARI patients may be caused by the ETT rather than by mechanical dysfunction of the lung. ATC is a very helpful mode to use in distinguishing between ventilatory failure caused by ETT and real ventilatory dependence.

Comparative effects of acute volume expansion and short-term training on thermal and cardiovascular responses to prolonged exercise

To investigate the hypothesis that increases in plasma volume (PV) are crucial to the cardiovascular and thermal adaptations resulting from training, eight moderately active males (Vo2max = 4.10 +/- 0.32 L/min; mean +/- SE) performed prolonged cycle exercise at 60% Vo2max during a control test (CON) and following infusion (10 mL/kg) of a 6% dextran solution (DEX). These responses were also compared with short-term training (TR) involving 3 days of cycling for 90-120 min at moderate intensity (60% Vo2max). During DEX, exercise cardiac output (Q) and stroke volume (SV) were persistently higher (p < 0.05) than CON, while heart rate (HR) was unchanged. In comparison, TR resulted in a lower (p < 0.05) HR at constant Q. In contrast with TR, in which the exercise response was unchanged from CON, the DEX condition produced a lower total peripheral resistance. Rectal temperature (Tre) was lowered (p < 0.05) both by DEX and TR, but the conditions differed in the time at which the reduction occurred. For DEX, the lower Tre was manifested early and persisted throughout exercise, whereas for TR the Tre was only lower later in exercise. Forearm blood flow, mean skin temperature, and sweat rate were not affected by DEX or TR. It is concluded that acute PV expansion does not affect the time-dependent response in cardiovascular function or thermoregulation during prolonged exercise in ambient conditions. The primary effects appear to be manifested during rest or soon after the onset of exercise.

Obesity and hypertension: roles of hyperinsulinemia, sympathetic nervous system and intrarenal mechanisms

Hypertension is a well-recognized complication of obesity. However, the mechanisms for the development of obesity hypertension are not known. One mechanism proposed is that the hyperinsulinemia present in obese hypertensive patients causes hypertension via sodium retaining and/or sympathetic nervous system stimulatory effects. However, numerous studies in dogs have revealed no evidence for such chronic pressor actions of hyperinsulinemia. This is in close agreement with studies in human insulinoma patients that show marked hyperinsulinemia and normal blood pressure. The appropriateness of the dog as an experimental model is strengthened by reports from our laboratory and others that inducing obesity in dogs reproduces many of the characteristics of obesity in humans, including insulin resistance, hyperinsulinemia, sodium retention, hypertriglyceridemia and hypertension. Recent studies in obese dogs have indicated that significant increases in renal medullary cellularity and intercellular matrix deposition could contribute to the sodium retention and hypertension. Additional evidence suggests that sympathetic nervous system stimulation also may contribute to the elevated blood pressure. However, the mechanisms through which obesity induces these changes and the temporal relationship between these factors and the development of the hypertension remains to be determined.