Effect of angiotensin-converting enzyme inhibitor on left ventricular parameters and circulating brain natriuretic peptide in elderly hypertensives with left venticular hypertrophy

The role of natriuretic peptide testing in guiding chronic heart failure management: review of available data and recommendations for use

The care of patients with heart failure can be challenging, with few objective tools available to assist in therapy decision-making. Natriuretic peptides are powerfully prognostic biomarkers in patients with heart failure and may represent an objective target for therapy. Accordingly, the use of biomarker-guided care with either B-type natriuretic peptide (BNP) or amino-terminal pro-B-type natriuretic peptide (NT-proBNP) has been recently explored. Over the past few years, a number of studies with heterogeneous inclusion criteria, methods and results have been performed. We have reviewed the available literature, summarizing the results of biomarker-guided heart failure trials and deriving recommendations for optimal application of biomarker-guided heart failure care based on the experience gained. In general, positive studies had low BNP or NT-proBNP target concentrations (∼100 pg/mL and ∼1000 pg/mL, respectively) and achieved lower natriuretic peptide concentrations compared with standard care. Patients in the biomarker-guided arms of the studies typically received more aggressive heart failure care and had no excess adverse outcomes. In the recent ProBNP Outpatient Tailored Chronic Heart Failure Therapy (PROTECT) study, patients treated with biomarker-guided care also had improved quality of life and significantly better reverse remodeling on echocardiography compared with patients who received standard care. In conclusion, heart failure therapy guided by a goal to reduce natriuretic peptide concentrations below prognostically-meaningful levels results in more aggressive heart failure care, is well tolerated and is associated with superior outcomes.

Natriuretic Peptide testing in primary care

The incidence, as well as the morbidity and mortality associated with heart failure (HF) continue to rise despite advances in diagnostics and therapeutics. A recent advance in the diagnostic and therapeutic approach to HF is the use of natriuretic peptide (NP) testing, including both B-type natriuretic peptide (BNP) and its amino terminal cleavage equivalent (NT-proBNP). NPs may be elevated at an early stage among those with symptoms as well among those without. The optimal approach for applying NP testing in general populations is to select the target population and optimal cut off values carefully. Superior diagnostic performance is observed among those with higher baseline risk (such as hypertensives or diabetics). As well, unlike for acute HF, the cut off value for outpatient testing for BNP is 20-40 pg/mL and for NTproBNP it is 100-150 ng/L. In symptomatic primary care patients, both BNP and NT-proBNP serve as excellent tools for excluding HF based on their excellent negative predictive values and their use may be cost effective. Among those with established HF, it is logical to assume that titration of treatment to achieve lower NPs levels may be advantageous. There are several ongoing trials looking at that prospect.

Natriuretic peptide-guided management of acutely destabilized heart failure: rationale and treatment algorithm

Natriuretic peptides (B-type natriuretic peptide [BNP] and N-terminal pro-B-type natriuretic peptide [NT]-proBNP) have been proven to be strong diagnostic and prognostic tools in the assessment of acutely decompensated heart failure. The emergence of BNP/NT-proBNP testing as a standard of care in this setting has helped to reduce healthcare costs, and may decrease adverse clinical outcomes. The use of BNP and NT-proBNP to "guide" treatment of acutely destabilized heart failure has recently grown. We present an overview of the value of BNP/NT-proBNP in the context of acute heart failure management and therapy optimization, and present an algorithm for natriuretic peptide-guided treatment of acutely destabilized heart failure.

Amino-terminal pro-B-type natriuretic peptide testing for inpatient monitoring and treatment guidance of acute destabilized heart failure

Although typically elevated at presentation in the context of destabilized heart failure (HF), amino-terminal pro-B-type natriuretic peptide (NT-proBNP) values typically decrease rapidly among patients who have a favorable response to therapy. Given this, it is natural to examine the relation between NT-proBNP and therapeutic interventions for acute HF. Both presentation and posttreatment NT-proBNP concentrations have some value for prognostication of recurrent HF hospitalization or death. However, the percent change in NT-proBNP after treatment for acute HF may be a more powerful method for risk stratification. Although prospective studies on the effect of NT-proBNP measurement in guiding therapy in acute destabilized HF are lacking, observational data suggest that a 30% decrease in NT-proBNP values during hospitalization is a reasonable goal. If a baseline measure of NT-proBNP is not available, an NT-proBNP level <4,000 ng/L after acute treatment is an alternative goal. Because the criteria for determining restabilization from destabilized HF prominently include clinical and routine laboratory testing rather than NP measures, the frequency of NT-proBNP measurement should not be excessive in patients with acute HF, with measures at baseline/presentation and after perceived recompensation to evaluate for the desired decrease in NT-proBNP concentrations. A remeasurement of NT-proBNP may also be useful for evaluation of new or worsened symptoms. In those patients without a decrease in NT-proBNP despite perceived recompensation from HF, a review of adequacy of treatment, goals of therapy, and consideration of prognosis is recommended.

Plasma N terminal pro-brain natriuretic peptide levels and its determinants in a multi-ethnic population

This study documents the determinants and plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) among hypertensive and normotensive subjects in a multi-ethnic population in the United Arab Emirates (UAE). We obtained demographic, anthropometric and clinical data, together with fasting NT-proBNP and biochemical indices from 128 hypertensive patients and 138 normotensive subjects matched for age, gender and ethnicity. Plasma NT-proBNP levels were significantly (P<0.001), and several-fold higher among hypertensives (median 5.92, inter quartile range (IQR): 1.79-18.48 pmol/l) than normotensives (median 1.78, IQR: 0.59-4.32 pmol/l) in the total study population, and the same was true for the ethnic groups separately. Similarly, plasma levels of glucose, blood urea nitrogen (BUN) and creatinine, but not insulin, were significantly (P<0.05) higher among hypertensives than normotensives. For all subjects combined, log NT-proBNP correlated positively and significantly with age (P<0.01), log glucose (P<0.05), systolic blood pressure (SBP, P<0.001), log BUN (P<0.001) and log creatinine (P<0.001). Multivariate regression analysis showed that NT-proBNP levels were independently and positively correlated with SBP, age, gender, log BUN, Emirati and South East Asian ethnic groups and inversely associated with current exercise. In conclusion, we found circulating levels of NT-proBNP to be significantly increased in hypertensive versus normotensive subjects in the UAE and independently related to SBP, age, gender, indices of renal function and possibly exercise. Our results further suggest a possible modulating effect of ethnicity on NT-proBNP levels.

The effects of medications on circulating levels of cardiac natriuretic peptides

Circulating cardiac natriuretic peptide levels are being used increasingly in a range of clinical circumstances. Since it is evident that drugs used in the treatment of cardiovascular disorders can modulate natriuretic peptide levels, we here review the literature documenting these effects. Diuretics, blockers of the renin-angiotensin system, vasodilator agents, dopamine-like agonists, amiodarone, and perhaps allopurinol and statins suppress natriuretic peptide levels, most obviously in heart failure. Beta-blockers stimulate natriuretic peptide concentrations in hypertensive subjects, whereas in heart failure they have little effect or are stimulatory in the short term and inhibitory with sustained therapy. Digitalis compounds and aspirin tend to increase natriuretic peptide levels, and calcium channel blocking agents have varying effects depending on the individual drug and duration of administration. The effects of other drugs are less clear. Additional information is needed regarding the effects of medications along with dissection of the role of altered cardiac secretion versus changes in plasma clearance as explanation for drug-induced perturbations in natriuretic peptide concentrations. In the meantime, clinicians need to consider the known effects of medications when interpreting plasma levels of the cardiac natriuretic peptides.

Pharmacological and Clinical Studies with Temocapril, an Angiotensin Converting Enzyme Inhibitor that is Excreted in the Bile

Temocapril is an angiotensin converting enzyme inhibitor (ACEI), a prodrug with a thiazepine ring. Its active form, temocaprilat, is slightly more potent than enalaprilat in inhibiting ACE isolated from rabbit lung. The inhibitory potency of temocaprilat on isolated rat aorta is 3 times that of enalaprilat. Temocapril is excreted in the bile and urine and can be used in patients with renal insufficiency. It reduces blood pressure without causing any significant change in heart rate or cardiac output. Temocapril has been reported to improve endothelial dysfunction in vitro by suppressing increased oxidative stress. In vivo it improves reactive hyperemia in patients with essential hypertension. It has been reported to prevent coronary vascular remodeling in vivo by suppressing local ACE and increased oxidative stress. In humans temocapril has been found to improve insulin resistance partly by increasing adiponectin levels. Cardiac remodeling was improved by temocapril not only in experiment animals but also in humans. It improves renal function and decreases urinary albumin excretion in diabetics as well as in hypertensive patients. Temocapril is currently marketed only in Japan. Considering its beneficial effects and unique pharmacokinetics, temocapril, is likely to be introduced in other countries as well.

Plasma BNP in patients on maintenance haemodialysis: a guide to management?

The number of patients requiring long-term haemodialysis is increasing throughout the world. Cardiovascular disease is much more common in these patients than in the general population and accounts for the majority of deaths. New approaches to management are clearly needed to reduce this excessive cardiovascular burden. We propose that circulating levels of the cardiac natriuretic peptides, B-type natriuretic peptide (BNP) in particular, might provide a useful, objective guide to the management of their hydration status and pharmacotherapy. An overview of the literature shows that plasma levels of the cardiac natriuretic peptides are increased in this patient population and reflect cardiac preload and afterload along with cardiac pathology, thereby providing an index of cardiovascular (especially cardiac) stress and distress. Circulating levels of the cardiac peptides change in parallel with cardiac load, especially across haemodialysis. Furthermore, there is robust evidence that natriuretic peptide levels are predictive of cardiovascular outcome in these patients. Accordingly, we hypothesize that management of their haemodialysis, and pharmacotherapy designed specifically to lower plasma BNP levels to, or close to, the normal range, will reduce the excessive burden on the cardiovascular system and thereby ultimately lower the incidence of cardiovascular disease. We outline, in broad terms, how a trial to test this hypothesis might be designed.

Opposite effects of losartan and atenolol on natriuretic peptides in patients with hypertension and left ventricular hypertrophy: a LIFE substudy

BACKGROUND

Secretion of natriuretic peptides is related to cardiac wall stress and influenced by the renin-angiotensin system. Therefore, we investigated the influence of blood pressure (BP) reduction with losartan versus atenolol on N-terminal pro-atrial natriuretic peptide (Nt-proANP) and N-terminal pro-brain natriuretic peptide (Nt-proBNP).

METHODS

In 183 patients with hypertension and electrocardiographic left ventricular (LV) hypertrophy, enrolled in the LIFE Study, we measured BP and serum Nt-proANP and Nt-proBNP by immunoassay after 2 weeks of placebo treatment and after 1, 2, 4, 6, 12, 24, 36 and 48 months of randomized treatment with losartan- or atenolol-based antihypertensive regimens.

RESULTS

There was no significant difference in BP at any time point between the two treatment groups. In patients treated with losartan, median Nt-proANP decreased gradually throughout the study, reaching significance after 6 months of treatment (1125-1060 pmol/l, P < 0.001), and Nt-proBNP decreased within the first month (24.7-18.7 pmol/l, P < 0.01) and stayed reduced throughout the study. During losartan-based antihypertensive treatment, Nt-proANP and Nt-proBNP as a percentage of baseline values were correlated to reductions in systolic BP (r = 0.11, P < 0.01 and r = 0.10, P = 0.01) and diastolic BP (r = 0.17, P < 0.001 and r = 0.07, P = 0.09). In atenolol-treated patients, Nt-proANP (1100-1640 pmol/l, P < 0.001) and Nt-proBNP (20.0-37.7 pmol/l, P < 0.001) increased during the first month, and remained elevated throughout the study. During atenolol-based antihypertensive treatment, changes in Nt-proANP (r = -0.16, P < 0.001) and Nt-proBNP (r = -0.07, P = 0.08) were negatively related to change in heart rate.

CONCLUSION

Nt-proANP and Nt-proBNP were reduced in parallel with BP in losartan-treated patients whereas they increased in parallel with decreased heart rate in atenolol-treated patients.

NT-proBNP in normoalbuminuric patients with Type 2 diabetes mellitus

OBJECTIVE

To examine levels of NT-proBNP and its relation to hypertension, as well as diastolic function in normoalbuminuric patients with Type 2 diabetes.

RESEARCH DESIGN AND METHODS

The study comprised 60 Type 2 diabetic patients without albuminuria. Thirty patients were normotensive and 30 had hypertension. Exclusion criteria were cardiac symptoms and an ejection fraction < 55%. Thirty age- and sex-matched normal subjects served as controls. Diastolic dysfunction was assessed with echocardiography, by means of mitral inflow and colour M-Mode flow propagation recordings.

RESULTS

Overall NT-proBNP was significantly elevated in the Type 2 diabetes group, compared with the controls [54.5 pg/ml (5-162) vs. 32.7 pg/ml (5-74.3) P = 0.02]. NT-proBNP was significantly higher among hypertensive patients compared with both normotensive patients and controls but no difference was found between the normotensive patients and the controls [58.0 pg/ml (8.5-162), P < 0.05 vs. 50.8 pg/ml (5-131) P = 0.4]. Patients with concentric and eccentric hypertrophy had significantly higher NT-proBNP levels compared with the control group [81.0 pg/ml (5-147), P < 0.001 and 66.8 pg/ml (42-128), P < 0.001], whereas patients with left ventricular remodelling (enlarged relative wall diameter but normal left ventricular mass) were comparable with the control group [42.3 pg/ml (8.3-142) P = 0.55]. Patients with left atrial enlargement also had incremental NT-proBNP values. NT-proBNP was only moderately correlated to age (r = 0.33, P < 0.05) and left ventricular diastolic diameter (r = 0.41, P < 0.05), but unrelated to diastolic function.

CONCLUSIONS

NT-proBNP is significantly increased in hypertensive, normoalbuminuric patients with Type 2 diabetes. These findings were related to left ventricular hypertrophy and increased left atrial and ventricular diameters.

Candesartan, an angiotensin II receptor blocker, improves left ventricular hypertrophy and insulin resistance

A growing body of evidence indicates that the renin-angiotensin system and insulin resistance play crucial roles in left ventricular hypertrophy (LVH) in patients with essential hypertension (EH). Angiotensin II receptor blockers (ARB) have been reported to regress LVH and improve insulin resistance. We tested the hypothesis that candesartan, an ARB, could regress LVH, in association with improvement of insulin resistance in EH patients. The study participants were nondiabetic and never-treated EH patients (n = 10). Candesartan was administered at a mean final dose of 10.4 +/- 2.1 mg/d for 24 weeks. Candesartan treatment resulted in a significant decrease of systolic and diastolic blood pressures, LV mass index (LVMI), homeostasis model assessment (HOMA) index, and plasma brain natriuretic peptide (BNP). A significant correlation was observed between the percent decrease in LVMI and that of both the HOMA index (r = 0.83, P <.001) and BNP (r = 0.71, P <.005). Stepwise regression analyses revealed that the percent decrease of HOMA index was an independent predictor for both percent decrease in LVMI and plasma BNP. Our findings suggest that pharmacological blockade of angiotensin II receptors by candesartan could improve LVH in never-treated EH patients, which may relate to the improvement of insulin resistance.

Prognostic information provided by serial measurements of brain natriuretic peptide in heart failure

BACKGROUND

Brain natriuretic peptide (BNP) levels predict prognosis in heart failure patients. We aimed to evaluate if serial measurements of BNP can give additional prognostic information.

METHODS

Eighty-four patients with systolic dysfunction had two measurements of BNP with an interval of 8 to 12 months and were followed in order to register the occurrence of death. The study was observational and prospectively designed. During follow-up, patients were treated according to state of the art. Physicians were kept blind to BNP levels.

RESULTS

The median follow-up was 1190 days. The median initial BNP level was 260.4 pg/ml and decreased to 123 pg/ml in the second measurement (P=0.001). The decrease in BNP was significantly associated with ACE-i dosage and with the use of a beta-blocker. All-cause mortality was 20.2%. Patients whose initial BNP level was above the median had a significantly higher hazard of dying (HR 2.96, 95% CI 1.06-8.26). The same was observed for those whose BNP increased between the first and the second measurement (HR 2.64, 95% CI 1.00-7.00). In multivariable analysis, baseline BNP above the median and increasing BNP were associated with shorter survival.

CONCLUSIONS

Higher baseline BNP and the increasing levels during follow-up were independently associated with mortality. The decrease in BNP levels was proportional to ACE-i dosage and larger among patients on beta-blockers. These results confirm the prognostic information provided by BNP determination and suggest that serial measurements give additional prognostic information.