Double-blind, placebo-controlled study to evaluate the effect of organic nitrates in patients with chronic heart failure treated with angiotensin-converting enzyme inhibition

Effect of nitroglycerin on splanchnic and pulmonary blood volume

BACKGROUND

Sublingual nitroglycerin (SL NTG) is useful for treating acute decompensated heart failure, possibly by increasing splanchnic capacitance and reducing left ventricular (LV) preload. We evaluated a radionuclide method to study these effects, initially in subjects without heart failure.

METHODS AND RESULTS

Red blood cells were labelled by an in vitro method. Abdominal and chest images were obtained at rest, showing relative regional blood volumes. The abdomen was then re-imaged during progressive escalation of intrathoracic pressure using continuous positive airway pressure to assess baseline splanchnic capacitance (pressure-volume relationship, PVR) and compliance (slope of PVR). The procedure was repeated after 0.6 mg SL NTG, followed by chest images. Relative splanchnic blood volume increased at rest after SL NTG (P < .002), signifying an increase in splanchnic capacitance. The slope of the splanchnic PVR decreased in proportion to the baseline PVR (P = .0014), signifying increased compliance. The relative pulmonary blood volume decreased in proportion to the increase in splanchnic blood volume (P = .01).

CONCLUSIONS

A semi-quantitative radionuclide method demonstrated the effect of SL NTG for increasing splanchnic capacitance and compliance, with a proportional decrease in pulmonary blood volume. These data may be applied to quantitatively evaluate the importance of splanchnic vasodilation as a mechanism of LV preload reduction in the treatment of heart failure.

CLINICAL TRIALS REGISTRATION

NCT02425566.

Effect of nitrate treatment on functional capacity and exercise time in patients with heart failure: a systematic review and meta-analysis

Objectives

Heart failure (HF) is a common and potentially fatal condition. In 2015, HF affected approximately 40 million people globally. Evidence showing that the use of nitrates can improve clinical outcomes in patients with HF is limited. This study aimed to assess the effect of nitrates on functional capacity and exercise time in patients with HF.

Methods

PubMed, Cochrane Library, and Embase databases were reviewed for articles on the use of nitrates and other treatments for patients with HF. The primary endpoints were the 6-minute walk test distance, exercise time, and quality of life. Secondary endpoints were all-cause mortality, arrhythmia, hospitalization, and worsening HF. The weighted mean difference, risk ratio, and 95% confidence interval were calculated.

Results

A total of 14 related studies that comprised 26,321 patients were included. No significant differences were found in the 6-minute walk test distance, exercise time, and quality of life between the nitrate and control treatment groups. There were also no differences in all-cause mortality, the incidence of arrhythmia, hospitalization, and worsening HF between these two groups.

Conclusion

Patients with HF who receive nitrate treatment do not have better quality of life or exercise capacity compared with controls.

Use of Nitrates and Risk of Cardiovascular Events in Patients With Heart Failure With Preserved Ejection Fraction

OBJECTIVE

To assess the association of nitrate use with cardiovascular events in patients with heart failure with preserved ejection fraction (HFpEF).

PATIENTS AND METHODS

Patient data were collected from the Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist trial, which had been conducted at 233 sites in 6 countries from August 10, 2006, through January 31, 2012. The primary outcome was the occurrence of a major adverse cardiovascular event (cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke) or heart failure hospitalization. The association between nitrate use and cardiovascular risk was evaluated using Cox proportional hazards analysis. In addition, we verified the results using propensity score-matched patients.

RESULTS

A total of 3417 patients with HFpEF were evaluated over a mean follow-up of 3.1 years, and 778 experienced a primary outcome event. The risk of primary outcome events was significantly higher in patients taking nitrates than in those not taking nitrates (hazard ratio [HR], 1.21; 95% CI, 1.01-1.46, P=.04). The risk of major adverse cardiovascular events was significantly higher in patients taking nitrates than in those not taking nitrates (HR, 1.32; 95% CI, 1.05-1.66, P=.01). Furthermore, the risk of hospitalization for heart failure was higher in patients taking nitrates (HR, 1.25; 95% CI, 0.99-1.60, P=.06), with propensity score-matched analyses revealing similar findings. In addition, a similar association was observed in various subgroups.

CONCLUSION

This study reported that nitrate use in patients with HFpEF was associated with a significantly increased risk of cardiovascular events.

Combination of Hydralazine and Isosorbide-Dinitrate in the Treatment of Patients with Heart Failure with Reduced Ejection Fraction

The use of direct acting vasodilators (the combination of hydralazine and isosorbide dinitrate -Hy+ISDN-) in heart failure with reduced ejection fraction (HFrEF) is supported by evidence, but rarely used.However, treatment with Hy+ISDN is guideline-recommended for HFrEF patients who cannot receive either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers due to intolerance or contraindication, and in self-identified African-American HFrEF patients who are symptomatic despite optimal neurohumoral therapy.The Hy+ISDN combination has arterial and venous vasodilating properties. It can decrease preload and afterload, decrease left ventricular end-diastolic diameter and the volume of mitral regurgitation, reduce left atrial and left ventricular wall tension, decrease pulmonary artery pressure and pulmonary arterial wedge pressure, increase stroke volume, and improve left ventricular ejection fraction, as well as induce left ventricular reverse remodelling. Furthermore, Hy+ISDN combination has antioxidant property, it affects endothelial dysfunction beneficially and improves NO bioavailability. Because of these benefits, this combination can improve the signs and symptoms of heart failure, exercise capacity and quality of life, and, most importantly, reduce morbidity and mortality in well-defined subgroups of HFrEF patients.Accordingly, this therapeutic option can in many cases play an essential role in the treatment of HFrEF.

Quality of life assessment in heart failure interventions: a 10-year (1996–2005) review

The increasing prevalence and poor prognosis associated with heart failure have prompted research to focus on improving quality of life (QoL) for heart failure patients. Research from 1996–2005 was systematically reviewed to identify randomized controlled trials that assessed QoL in heart failure. In 120 studies, 44 were medication trials; 19 surgical/procedural interventions; and 57 patient care/service delivery interventions. Studies were summarized in terms of aim, population, QoL measures used and QoL findings. Studies used 47 different measures of QoL-generic, health-related, condition-specific, domain-specific and utility measures. Most used a single QoL measure. In 87%, a condition specific QoL measure was used, with the Minnesota Living with Heart Failure Questionnaire being the favoured assessment tool. The range of QoL measures in use poses challenges for development of cumulative knowledge. Although comparability across studies is important, this must be informed by the responsiveness of the instrument selected. As carried out in other cardiac groups, comparative evaluations of instrument responsiveness are needed in heart failure. Eur J Cardiovasc Prev Rehabil 14:589-607 © 2007 The European Society of Cardiology

Contemporary clinical trial updates in heart failure

PURPOSE OF REVIEW

Heart failure is a major source of cardiovascular morbidity and mortality worldwide. The field has benefited from steady progress, and there are now multiple strategies - medical and surgical - to improve cardiovascular outcomes. The quest continues for enhanced pathophysiologic insights and therapies.

RECENT FINDINGS

The chosen studies highlight new ways of treating heart failure with reduced ejection fraction (HFrEF) with pharmacotherapy such as sacubitril/valsartan and explore the role of antimicrobial therapy for chronic Chagas' cardiomyopathy. The role of iron supplementation, spinal cord stimulation and gene therapy are evaluated. The treatment of heart failure with preserved ejection fraction (HFpEF) is scrutinized, and the role of nitrates is discussed. The use of left ventricular assist devices in wider populations of HFrEF patients is considered.

SUMMARY

These pivotal contemporary trials will impact bedside management. Sacubitril/valsartan's mortality benefit in HFrEF and the negative effect of nitrates in HFpEF provide novel insights. Progress with durable mechanical circulatory support and nonpharmacological approaches to heart failure management expand therapeutic options.

Isosorbide Mononitrate in Heart Failure with Preserved Ejection Fraction

BACKGROUND

Nitrates are commonly prescribed to enhance activity tolerance in patients with heart failure and a preserved ejection fraction. We compared the effect of isosorbide mononitrate or placebo on daily activity in such patients.

METHODS

In this multicenter, double-blind, crossover study, 110 patients with heart failure and a preserved ejection fraction were randomly assigned to a 6-week dose-escalation regimen of isosorbide mononitrate (from 30 mg to 60 mg to 120 mg once daily) or placebo, with subsequent crossover to the other group for 6 weeks. The primary end point was the daily activity level, quantified as the average daily accelerometer units during the 120-mg phase, as assessed by patient-worn accelerometers. Secondary end points included hours of activity per day during the 120-mg phase, daily accelerometer units during all three dose regimens, quality-of-life scores, 6-minute walk distance, and levels of N-terminal pro-brain natriuretic peptide (NT-proBNP).

RESULTS

In the group receiving the 120-mg dose of isosorbide mononitrate, as compared with the placebo group, there was a nonsignificant trend toward lower daily activity (-381 accelerometer units; 95% confidence interval [CI], -780 to 17; P=0.06) and a significant decrease in hours of activity per day (-0.30 hours; 95% CI, -0.55 to -0.05; P=0.02). During all dose regimens, activity in the isosorbide mononitrate group was lower than that in the placebo group (-439 accelerometer units; 95% CI, -792 to -86; P=0.02). Activity levels decreased progressively and significantly with increased doses of isosorbide mononitrate (but not placebo). There were no significant between-group differences in the 6-minute walk distance, quality-of-life scores, or NT-proBNP levels.

CONCLUSIONS

Patients with heart failure and a preserved ejection fraction who received isosorbide mononitrate were less active and did not have better quality of life or submaximal exercise capacity than did patients who received placebo. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT02053493.).

Factors associated with 30-day readmission of patients with heart failure from a Japanese administrative database

Background

Numerous studies have been conducted in many countries to identify the factors associated with readmission of patients with heart failure (HF). However, there have been no such studies utilizing a large-scale administrative database in Japan. This study aimed to establish the factors associated with 30-day readmission of patients with HF using a Japanese nationwide administrative database.

Methods

Data of the index admissions of 68,257 patients discharged from 1057 participating hospitals between April 1, 2012 and March 31, 2013 were analyzed. Patients were divided into the 30-day readmission group and no readmission group according to whether unplanned HF readmission occurred within 30 days after discharge. Study variables included age, sex, New York Heart Association functional class (NYHA) at admission, Charlson Comorbidity Index (CCI), length of stay in hospital (LOS), body mass index (BMI) at admission, hospital volume reflected by the number of cases hospitalized with HF, and medical treatment at discharge.

Results

The 30-day readmission and no readmission groups included 4479 and 63,778 patients, respectively. The independent factors associated with the increase in 30-day readmission were older age, higher NYHA, higher CCI, and use of the following drugs at discharge: beta blockers, loop diuretics, thiazide, and nitrates. In contrast, the independent factors associated with the decrease in 30-day readmission were longer LOS, higher BMI, and the use of angiotensin converting enzyme inhibitors (ACEs) or angiotensin II receptor blockers (ARBs), calcium channel blockers, and spironolactone.

Conclusions

The results suggest that, especially during the first few weeks after discharge, careful management of HF outpatients with advanced age, high disease severity, multiple comorbidities, or taking beta blockers, loop diuretics, thiazide, and nitrates at discharge may be crucial for reducing the 30-day readmission rate.

Hydralazine and nitrates alone or combined for the management of chronic heart failure: A systematic review

BACKGROUND

Hydralazine (H) and nitrates (Ns), when combined, reduced morbidity and mortality in some trials of chronic heart failure (CHF). It is unclear whether either agent used alone provides similar benefits. We aimed to evaluate the effects of H and/or N in patients with CHF.

METHODS

A systematic review of randomised trials assessing the effects of H and N in CHF. For meta-analysis, only the endpoints of all-cause mortality and cardiovascular mortality were considered.

RESULTS

In seven trials evaluating H&N in 2626 patients, combination therapy reduced all-cause mortality (OR 0.72; 95% CI 0.55-0.95; p=0.02), and cardiovascular mortality (OR 0.75; 95% CI 0.57-0.99; p=0.04) compared to placebo. However, when compared to angiotensin converting enzyme inhibitors (ACEIs), combination therapy was associated with higher all-cause mortality (OR 1.35; 95% CI 1.03-1.76; p=0.03), and cardiovascular mortality (OR 1.37; 95% CI 1.04-1.81; p=0.03). For N alone, ten trials including 375 patients reported all-cause mortality and showed a trend to harm (13 deaths in those assigned to nitrates and 7 to placebo; OR 2.13; 95% CI 0.88-5.13; p=0.09). For H alone, three trials showed no difference in all-cause mortality compared to placebo (OR 0.96; 95% CI 0.37-2.47; p=0.93), and two trials suggested inferiority to ACEI (OR 2.28; 95% CI 1.03-5.04; p=0.04).

CONCLUSIONS

Compared to placebo, H&N reduces mortality in patients with CHF. Whether race or background therapy influences benefit is uncertain, but on direct comparison H&N appears inferior to ACEI. There is little evidence to support the use of either drug alone in CHF.

Current perspectives on hydralazine and nitrate therapies in heart failure

The origins of the hydralazine/isosorbide dinitrate (H+ISDN) combination therapy are rooted in the first large-scale clinical trial in heart failure: V-HeFT I. Initially utilized for the balanced vasodilatory properties of each drug, we now know there is "more to the story." In fact, the maintenance of the nitroso-redox balance may be the true mechanism of benefit. Since the publication of V-HeFT I 30 years ago, H+ISDN has been the subject of much discussion and debate. Regardless of the many controversies surrounding H+ISDN, one thing is clear: therapy is underutilized and many patients who could benefit never receive the drugs. Ongoing physician and patient education are mandatory to improve the rates of H+ISDN use.

Enhancing vascular relaxing effects of nitric oxide-donor ruthenium complexes

Ruthenium-derived complexes have emerged as new nitric oxide (NO) donors that may help circumvent the NO deficiency that impairs vasodilation. NO in vessels can be produced by the endothelial cells and/or released by NO donors. NO interacts with soluble guanylyl-cyclase to produce cGMP to activate the kinase-G pathway. As a result, conductance arteries, veins and resistance arteries dilate, whereas the cytosolic Ca2+ levels in the smooth muscle cells decrease. NO also reacts with oxygen or the superoxide anion, to generate reactive oxygen species that modulate NO-induced vasodilation. In this article, we focus on NO production by NO synthase and discuss the vascular changes taking place during hypertension originating from endothelial dysfunction. We will describe how the NO released from ruthenium-derived complexes enhances the vascular effects arising from failed NO generation or lack of NO bioavailability. In addition, how ruthenium-derived NO donors induce the hypotensive effect by vasodilation is also discussed.

A randomized pilot study of aortic waveform guided therapy in chronic heart failure

BACKGROUND

Medication treatment decisions in heart failure (HF) are currently informed by measurements of brachial artery pressure, but ventricular afterload is more accurately represented by central aortic pressure, which differs from brachial pressure. We sought to determine whether aggressive titration of vasoactive medicines beyond goal-directed heart failure medical therapy (GDMT) based upon aortic pressure improves exercise capacity and cardiovascular structure-function.

METHODS AND RESULTS

Subjects with chronic HF (n=50) underwent cardiopulmonary exercise testing, echocardiography, and arterial tonometry to measure aortic pressure and augmentation index, and were then randomized to aortic pressure-guided treatment (active, n=23) or conventional therapy (control, n=27). Subjects returned for 6 monthly visits wherein GDMT was first optimized. Additional vasoactive therapies were then sequentially added with the goal to reduce aortic augmentation index to 0% (active) or if brachial pressure remained elevated (control). Subjects randomized to active treatment experienced greater improvement in peak oxygen consumption compared with controls (1.37±3.76 versus -0.65±2.21 mL min(-1) kg(-1), P=0.025) though reductions in aortic augmentation index were similar (-7±9% versus -5±6%, P=0.46). Forward stroke volume increased while arterial elastance and left ventricular volumes decreased in all participants, with no between-group difference. Subjects randomized to active treatment were more likely to receive additional vasoactive therapies including nitrates, aldosterone antagonists and hydralazine, with no increased risk of hypotension or worsening renal function.

CONCLUSIONS

Maximization of goal-directed medical therapy in heart failure patients may enhance afterload reduction and lead to reverse remodeling, while additional medicine titration based upon aortic pressure data improves exercise capacity in patients with heart failure.

Nitrate therapy for heart failure: benefits and strategies to overcome tolerance

Combination therapy with hydralazine and nitrates can improve outcomes in patients with heart failure and low ejection fraction. However, this combination is underused in clinical practice for several reasons, including side effects related to hydralazine and polypharmacy. Some of the benefits seen with hydralazine, including afterload reduction and attenuation of nitrate tolerance, have also been observed with angiotensin-converting enzyme inhibitors. Demonstrating similar clinical benefits with nitrates plus angiotensin-converting enzyme inhibitor therapy alone, in the absence of hydralazine, may represent an opportunity to improve heart failure care by increasing the use of nitrates. In this paper, we summarize data that support studying such an approach.

Coadministration of carvedilol attenuates nitrate tolerance by preventing cytochrome p450 depletion

BACKGROUND

Long-term administration of nitroglycerin (NTG) causes tolerance secondary to increased vascular formation of reactive oxygen species. Carvedilol, which has potent antioxidant activity in addition to functioning as an adrenergic blocker, prevents nitrate tolerance by a still to be elucidated mechanism. The present study investigated how carvedilol attenuates nitrate tolerance, particularly with reference to cytochrome P450 (CYP), an enzyme involved in the development of tolerance.

METHODS AND RESULTS

Male Wistar rats were subjected to 48-h continuous infusion of NTG alone (0.5 mg/h) or NTG with concomitant carvedilol (20 or 100 microg/h), and then compared with vehicle-treated rats (4 groups; n=6 in each group). Following the continuous administration, nitrate tolerance, assessed by bolus NTG injections, was hemodynamically prevented by coadministration of carvedilol. Levels of CYP1A1/1A2, superoxide production, and phosphorylated vasodilator-stimulated phosphoprotein at serine 239 (P-VASP) were examined in the aortic wall and heart tissue. When NTG alone was continuously administered, vascular superoxide was produced, there was a decrease in the cardiac CYP1A1/1A2 level, and depletion of P-VASP. However, each of these changes induced by continuous NTG administration was significantly attenuated by coadministration of carvedilol and the extent of attenuation was more pronounced at the higher dose (100 microg/h).

CONCLUSIONS

Coadministration of carvedilol attenuates nitrate tolerance through maintenance of NO/cGMP pathway activity by preventing free radical generation and CYP depletion.

Side effects of using nitrates to treat heart failure and the acute coronary syndromes, unstable angina and acute myocardial infarction

Nitrates are potent venous dilators and anti-ischemic agents. They are widely used for the relief of chest pain and pulmonary congestion in patients with acute coronary syndromes and heart failure. Nitrates, however, do not reduce mortality in patients with acute coronary syndromes. Combination of nitrates and hydralazine when given in addition to beta-blockers and angiotensin-converting enzyme (ACE) inhibitors reduce mortality and heart failure hospitalizations in patients with heart failure due to left ventricular systolic dysfunction who are of African-American origin. Side effects during nitrate therapy are common but are less well described in the literature compared with the reported side effects in patients with stable angina pectoris. The reported incidence of side effects varies highly among different studies and among various disease states. Headache is the most commonly reported side effect with an incidence of 12% in acute heart failure, 41-73% in chronic heart failure, 3-19% in unstable angina and 2-26% in acute myocardial infarction. The reported incidence of hypotension also differs: 5-10% in acute heart failure, 20% in chronic heart failure, 9% in unstable angina and < 1-48% in acute myocardial infarction, with the incidence being much higher with concomitant nitrate therapy plus angiotensin-converting enzyme inhibitors. Reported incidence of dizziness is as low as 1% in patients with acute myocardial infarction to as high as 29% in patients with heart failure. Severe headaches and/or symptomatic hypotension may necessitate discontinuation of nitrate therapy. Severe life threatening hypotension or even death may occur when nitrates are used in patients with acute inferior myocardial infarction associated with right ventricular dysfunction or infarction, or with concomitant use of phosphodiesterase-5 inhibitors or N-acetylcysteine. Despite the disturbing observational reports in the literature that continuous and prolonged use of nitrates may lead to increased mortality and recurrent myocardial infarction in patients with stable coronary artery disease, no such adverse effects of nitrates have been reported in the large randomized trials in patients with acute myocardial infarction or chronic heart failure.

The oxidative stress concept of nitrate tolerance and the antioxidant properties of hydralazine

The hemodynamic and anti-ischemic effects of nitroglycerin (NTG) are rapidly blunted as a result of the development of nitrate tolerance. With initiation of NTG therapy, it is possible to detect neurohormonal activation and intravascular volume expansion. These so-called pseudotolerance mechanisms may compromise the vasodilatory effects of NTG. Long-term nitrate treatment also is associated with decreased vascular responsiveness caused by changes in intrinsic mechanisms of the tolerant vasculature itself. According to the oxidative stress concept, increased vascular superoxide (O2-) production and an increased sensitivity to vasoconstrictors secondary to activation of protein kinase C contribute to the development of tolerance. Nicotinamide adenine dinucleotide phosphate oxidase and the uncoupled endothelial nitric oxide synthase may be O2- -producing enzymes. Nitric oxide (NO) and O2-, both derived from NTG and the vessel wall, form peroxynitrite in a diffusion-limited rapid reaction. Peroxynitrite, O2-, or both may be responsible for the development of nitrate tolerance and cross-tolerance to direct NO donors (eg, sodium nitroprusside, sydnonimines) and endothelium-dependent NO synthase-activating vasodilators. Hydralazine is an efficient reactive oxygen species (ROS) scavenger and an inhibitor of O2- generation. When given concomitantly with NTG, hydralazine prevents the development of nitrate tolerance and normalizes endogenous rates of vascular O2- production. Recent experimental work has defined new tolerance mechanisms, including inhibition of the enzyme that bioactivates NTG (ie, mitochondrial aldehyde dehydrogenase isoform 2 [ALDH2]) and mitochondria as potential sources of ROS. NTG-induced ROS inhibit the bioactivation of NTG by ALDH2. Both mechanisms increase oxidative stress and impair NTG bioactivation, and now converge at the level of ALDH2 to support a new theory for NTG tolerance and NTG-induced endothelial dysfunction. The consequences of these processes for NTG downstream targets (eg, soluble guanylyl cyclase, cyclic guanosine monophosphate-dependent protein kinase), toxic effects contributing to endothelial dysfunction (eg, prostacyclin synthase inhibition) and novel applications of the antioxidant properties of hydralazine are discussed.

Survey of the use of organic nitrates for the treatment of chronic congestive heart failure in the United States

A survey of members of the Heart Failure Society of America revealed that despite their lack of approval by the United States Food and Drug Administration, nitrates are widely used in patients with chronic congestive heart failure (CHF). Most members reported using nitrates in patients with ischemic (90%) and nonischemic (81%) causes of chronic CHF, especially those with symptomatic CHF (43% reported using nitrates in >50% of their patients with ischemic and 25% with nonischemic causes). Ninety-six percent reported using nitrates to reduce symptoms, 74% for hemodynamic improvement, 65% for better exercise tolerance, and only 14% for left ventricular reversed remodeling. Nitrates were always combined with hydralazine in 25% of patients and occasionally combined with hydralazine in 67%.

A survey of outpatient management of elderly heart failure patients in Poland—treatment patterns

BACKGROUND

Despite the fact that heart failure constitutes a major health problem there are only limited data regarding pharmacotherapy along with characterization and prognosis of heart failure in the community.

AIM

The aim of this study was to investigate treatment pattern in ambulatory patients with heart failure.

METHODS

The study is a cross-country epidemiological survey, based on registration, by 417 participating physicians, 50 consecutive ambulatory patients aged >/=65 years seeking medical care for any cause.

RESULTS

From a total of 19,877 individuals, 10,579 patients (3901 men and 6678 women, 53% of total) were diagnosed with HF. Therapy with angiotensin converting enzyme inhibitors was recommended in 68%, long acting nitrates in 62%, diuretics in 55%, cardiac glycosides in 31%, Ca blockers in 29% and beta blockers in 22% of all individuals with HF. The prevalence of particular groups of drugs administered in both genders was similar with the exception for calcium blockers, which were more frequently used in women (p<0.001), whereas long acting nitrates in men (p<0.001). In general, angiotensin converting enzyme inhibitors, long acting nitrates and cardiac glycosides use increased with age. On the contrary, beta blockers and calcium blockers were given mostly to younger patients. The most sick patients were more likely to receive angiotensin converting enzyme inhibitors, cardiac glycosides, long acting nitrates and diuretics, whereas less frequently beta blockers and calcium blockers. Combination therapy was used relatively rarely, with lowest percentage in NYHA IV.

CONCLUSION

Compared to the other population studies, both angiotensin converting enzyme inhibitors and beta blockers were used relatively more frequently, although in the absolute terms the latter was clearly underused. The high rate of Ca blockers prescription is a matter of concern. More attention should be paid to optimising combination usage and introducing beta blockers early in all stable patients.

A nitric oxide‐releasing derivative of enalapril, NCX 899, prevents progressive cardiac dysfunction and remodeling in hamsters with heart failure

Nitric oxide (NO) production is known to be impaired in heart failure. A new compound (NCX 899), a NO-releasing derivative of enalapril was characterized, and its actions were evaluated in Bio 14.6 cardiomyopathic (CM) hamsters with heart failure. The hamsters were randomized to oral treatment for 4 weeks with vehicle (n=11), NCX 899 (NCX, 25 mg/kg, n=10), or enalapril (25 mg/kg, n=10). In the vehicle group, fractional shortening by echocardiography decreased (-23.6+/-2.0%) and LV end-diastolic dimension) increased (+10.9+/-1.0%), whereas fractional shortening increased (+17.5+/-4.4%) in NCX and was unchanged in the enalapril group (both P<0.01 vs. vehicle). End-diastolic dimension decreased only in NCX. LV contractility (LVdP/dt max and Emax) was significantly greater in NCX than in enalapril or vehicle, while relaxation (Tau) was shortened in both NCX and enalapril vs. vehicle. ACE activity was inhibited equally by NCX and enalapril in the CM hamster, and plasma nitrate levels were increased only in NCX (P<0.05 vs. enalapril and vehicle). In aortic strips endothelium-independent relaxation occurred only with NCX. The superior effects of NO-releasing enalapril (NCX) vs. enalapril alone to enhance vascular effects, increase LV contractility and prevent unfavorable remodeling and are consistent with vascular delivery of exogenous NO. NCX 899 may hold promise for the future treatment of heart failure.

Effects of a Comprehensive Rehabilitation Program on Quality of Life in Patients With Chronic Heart Failure

This evaluation was performed to assess the effects of a new, comprehensive outpatient rehabilitation program on generic and disease-specific quality of life related to exercise tolerance in stable chronic heart failure patients. Fifty-one patients (aged 59+/-11 years; 84% men) were treated for 12 weeks. Patients underwent optimized drug treatment, exercise training, and counseling and education. At baseline and at the end of the program, functional status, exercise capacity, and quality of life were assessed using the Medical Outcomes Study 36-item Short-Form Health Survey and the Minnesota Living with Heart Failure Questionnaire. Left ventricular ejection fraction and New York Heart Association functional class, as well as measures of physical fitness and walking distance covered in 6 minutes, improved significantly (by 11%-20% and by 58% on average, respectively). Physical functioning (effect size, 0.38; p<0.0001), role functioning (effect size, 0.17; p<0.05), and mental component score (effect size, 0.47; p<0.0001) on the questionnaire improved significantly. Disease-specific quality of life improved in sum score (effect size, 0.24; p<0.0001) and physical component score (effect size, 0.35; p<0.0001). The latter was inversely correlated to improvement in peak power output (r= -0.31; p<0.05). In patients with stable chronic heart failure, significant improvements in both generic and disease-specific quality of life related to improved exercise tolerance can be achieved within 12 weeks of comprehensive rehabilitation.

Beneficial effects of angiotensin-converting enzyme inhibitor and nitrate association on left ventricular remodeling in patients with large acute myocardial infarction: the Delapril Remodeling after Acute Myocardial Infarction (DRAMI) trial

BACKGROUND

In the large-scale trial, Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-3 (GISSI-3), patients receiving the combination of lisinopril and glyceryl trinitrate benefited most from experimental therapy. Therefore, a multicenter, randomized, double-blind study, Delapril Remodeling After Acute Myocardial Infarction (DRAMI), was designed to assess (1) the possible additive beneficial effect on left ventricular remodeling of nitrates when combined with an angiotensin-converting enzyme inhibitor (ACEI), and (2) the tolerability of a new ACEI, delapril, in respect to lisinopril in patients with large myocardial infarction (MI).

METHODS

A total of 177 patients were randomized to receive delapril plus isosorbide-5-mononitrate (IS5MN) placebo, delapril plus IS5MN, lisinopril plus IS5MN placebo, or lisinopril plus IS5MN starting within the first 36 hours after the onset of symptoms and continuing for 3 months.

RESULTS

More than 80% of the patients showed extensive ST-segment changes and 36.7% had signs or symptoms of heart failure during the first 36 hours. Over 3 months, IS5MN reduced, by 76%, the increase in LVEDV (17.4 +/- 5.0 mL placebo vs 4.2 +/- 4.4 mL IS5MN, P =.0439), reversed the increase in LVESV (7.5 +/- 3.9 mL placebo vs -5.5 +/- 2.9 mL IS5MN, P =.0052), and increased the recovery of LVEF (1.9% +/- 1.3% placebo vs 6.7% +/- 1.2% IS5MN, P =.0119). Overall, 3-month mortality was 10.2%; the most frequent clinical events were new episodes of severe heart failure (18.1%), persistent hypotension (10.7%), and post-MI angina (18.1%), with no differences between treatment groups.

CONCLUSIONS

Administration for 3 months of IS5MN combined with an ACEI, both started within 36 hours from the onset of symptoms, was safe and effective in reducing LV dilation and dysfunction after MI. The 2 ACEIs, delapril and lisinopril, appeared to be equally well tolerated.

Mechanisms underlying nitrate-induced endothelial dysfunction: insight from experimental and clinical studies

The hemodynamic and anti-ischemic effects of nitroglycerin (NTG) are rapidly blunted due to the development of nitrate tolerance. With initiation of nitroglycerin therapy one can detect neurohormonal activation and signs for intravascular volume expansion. These so called pseudotolerance mechanisms may compromise nitroglycerin's vasodilatory effects. Long-term treatment with nitroglycerin is also associated with a decreased responsiveness of the vasculature to nitroglycerin's vasorelaxant potency suggesting changes in intrinsic mechanisms of the tolerant vasculature itself may also contribute to tolerance. More recent experimental work defined new mechanisms of tolerance such as increased vascular superoxide production and increased sensitivity to vasoconstrictors secondary to an activation of the intracellular second messenger protein kinase C. As potential superoxide producing enzymes, the NADPH oxidase and the nitric oxide synthase have been identified. Nitroglycerin-induced stimulation of oxygen-derived free radicals together with NO derived from nitroglycerin may lead to the formation of peroxynitrite, which may be responsible for the development of tolerance as well as for the development of cross tolerance to endothelium-dependent vasodilators. The oxidative stress concept of tolerance and cross tolerance may explain why radical scavengers such as vitamin C or substances which reduce oxidative stress, such as ACE-inhibitors, AT1 receptor blockers or folic acid, are able to beneficially influence both tolerance and nitroglycerin-induced endothelial dysfunction. New aspects concerning the role of oxidative stress in nitrate tolerance and nitrate induced endothelial dysfunction and the consequences for the NO/cyclicGMP downstream target, the cGMP-dependent protein kinase will be discussed.

Present and future pharmacotherapy for heart failure

The pharmacotherapy currently recommended by the American College of Cardiology and the American Heart Association for heart failure (HF) is a diuretic, an angiotensin-converting enzyme inhibitor (ACEI), a beta-adrenoceptor antagonist and (usually) digitalis. This current treatment of HF may be improved by optimising the dose of ACEI used, as increasing the dose of lisinopril increases its benefits in HF. Selective angiotensin receptor-1 (AT(1)) antagonists are effective alternatives for those who cannot tolerate ACEIs. AT(1) antagonists may also be used in combination with ACEIs, as some studies have shown cumulative benefits for the combination. In addition to being used in Stage IV HF patients, in whom it has a marked benefit, spironolactone should be studied in less severe HF and in the presence of beta-blockers. The use of carvedilol, extended-release metoprolol and bisoprolol should be extended to severe HF patients as these agents have been shown to decrease mortality in this group. The ancillary properties of carvedilol, particularly antagonism at prejunctional beta -adrenoceptors, may give it additional benefits to selective beta(1)-adrenoceptor antagonists. Celiprolol and bucindolol are not the beta-blockers of choice in HF, as they do not decrease mortality. Although digitalis does not reduce mortality, it remains the only option for a long-term positive inotropic effect, as the long-term use of the phosphodiesterase inhibitors is associated with increased mortality. The calcium sensitising drug levosimendan may be useful in the hospital treatment of decompensated HF to increase cardiac output and improve dyspnoea and fatigue. The antiarrhythmic drug amiodarone should probably be used in patients at high risk of arrhythmic or sudden death, although this treatment may soon be superseded by the more expensive implanted cardioverter defibrillators, which are probably more effective and have fewer side effects. The natriuretic peptide nesiritide has recently been introduced for the hospital treatment of decompensated HF. Novel drugs that may be beneficial in the treatment of HF include the vasopeptidase inhibitors and the selective endothelin-A receptor antagonists but these require much more investigation. However, disappointing results have been obtained in a large clinical trial of the tumour necrosis factor alpha antagonist etanercept, where no likelihood of a difference between placebo and etanercept was observed. Small clinical trials with recombinant growth hormone to thicken ventricles in dilated cardiomyopathy have given variable results.

Impaired endothelium-mediated vasodilation in heart failure: clinical evidence and the potential for therapy

Numerous studies in the last decade have clearly shown an attenuated endothelium-dependent vasodilation in patients with chronic heart failure. This abnormality has been demonstrated in the peripheral, pulmonary, and coronary circulation in patients with both ischemic and nonischemic cardiomyopathy; its magnitude correlates with the severity of symptoms. Endothelial dysfunction in patients with cardiomyopathy and a relatively new onset of symptoms suggests that change in endothelial function occurs early in the course of the disease. In contrast to other circulatory beds, renal circulation has shown significant vasodilatory response to endothelial stimulation. The development of endothelial dysfunction may not be homogeneous, and its magnitude may differ among circulatory systems. Although the clinical implications of the attenuated endothelium-dependent vasodilation in heart failure are not clear, this condition may lead to decreased organ perfusion, impaired exercise tolerance, and progression of disease. Many therapeutic interventions have resulted in improvement of endothelial function in patients with heart failure. Some of these interventions have also proven effective in enhancing exercise capacity, symptoms, and survival in patients with heart failure. This association suggests a therapeutic role for improvement of endothelial function in patients with chronic heart failure.

Health-related quality of life measurement in heart failure: challenges for the new millennium

Health-related quality of life (HRQL), representing a patient-driven end point, has been increasingly emphasized in randomized clinical trials of new heart failure therapies. Measurement of HRQL depends on the use of validated instruments, with attention paid to the timing of administration and analysis of data in the context of conventional morbidity and mortality end points. In a review of HRQL measurement in heart failure drug trials published from 1966 to 1999, we found that important data, such as the number of participating subjects, are often lacking. HRQL is analyzed as a stand-alone end point without consideration of the underlying clinical trajectory of the disease. Improvements in trials methodology are warranted if quality-of-life data are to be meaningful in the determination of drug efficacy in heart failure.

What is the optimal medical management of ischaemic heart failure?

Ischaemic heart disease is probably the most important cause of heart failure. All patients with heart failure may benefit from treatment designed to retard progressive ventricular dysfunction and arrhythmias. Patients with heart failure due to ischaemic heart disease may also, theoretically, benefit from treatments designed to relieve ischaemia and prevent coronary occlusion and from revascularisation. However, there is little evidence to show that effective treatments, such as angiotensin converting enzyme (ACE) inhibitors and beta-blockers, exert different effects in patients with heart failure with or without coronary disease. Moreover, there is no evidence that treatment directed specifically at myocardial ischaemia, whether or not symptomatic, or coronary disease alters outcome in patients with heart failure. Some agents, such as aspirin, designed to reduce the risk of coronary occlusion appear ineffective or harmful in patients with heart failure. There is no evidence, yet, that revascularisation improves prognosis in patients with heart failure, even in patients who are demonstrated to have extensive myocardial hibernation. On current evidence, revascularisation should be reserved for the relief of angina. Large-scale, randomised controlled trials are currently underway investigating the role of specific treatments targeted at coronary syndromes in patients who have heart failure. The CHRISTMAS study is investigating the effects of carvedilol in a large cohort of patients with and without hibernating myocardium. The WATCH study is comparing the efficacy of aspirin, clopidogrel and warfarin. The HEART-UK study is assessing the effect of revascularisation on mortality in patients with heart failure and myocardial hibernation. Smaller scale studies are currently assessing the safety and efficacy of statin therapy in patients with heart failure. Only when the results of these and other studies are known will it be possible to come to firm conclusions about whether patients with heart failure and coronary disease should be treated differently from other patients with heart failure due to left ventricular systolic dysfunction.

Effects of a nitrate-free interval on tolerance, vasoconstrictor sensitivity and vascular superoxide production

OBJECTIVES

In the present study, we tested whether a nitrate-free interval is able to prevent increases in vascular superoxide (O2*-) and the development of hypersensitivity to vasoconstrictors and whether this may result in restoration of vascular nitroglycerin (NTG) sensitivity.

BACKGROUND

Intermittent NTG-patch treatment (12 h patch on/patch-off) has been shown to increase ischemic periods in patients with stable coronary arteries, suggesting a rebound-like situation during the patch-off period. Recently, we demonstrated that long-term treatment with NTG induces tolerance, which was in part related to increases in vascular O2*- and increased vasoconstrictor sensitivity.

METHODS

New Zealand white rabbits received a continuous application of NTG patches (0.4 mg/h) or an intermittent application of NTG patches (12 h patch on, 12 h patch off) for three days. Isometric tension studies were performed with aortic rings, and vascular O2*- was estimated using lucigenin-derived chemiluminescence (5 micromol/liter). Expression of the copper/zinc (Cu/Zn) superoxide dismutase (SOD) was assessed by Western blotting, and SOD activity was measured by autooxidation of 6-hydroxydopamine.

RESULTS

Continuous treatment with NTG caused tolerance to NTG, cross-tolerance to the endothelium-dependent vasodilator acetylcholine, increased vascular O2*-, reduced Cu/Zn SOD expression and increased sensitivity to vasoconstrictors such as phenylephrine, serotonin and angiotensin II. On/off treatment with NTG improved tolerance, corrected endothelial dysfunction and decreased vascular O2*-. In addition the reduction in SOD expression was less pronounced, whereas increases in the sensitivity to vasoconstrictors such as phenylephrine and serotonin remained nearly unchanged.

CONCLUSIONS

Enhanced vasoconstrictor sensitivity may explain, at least in part, the rebound phenomena observed in patients during a 12-h NTG patch-off period.

Pharmacotherapy of systolic heart failure: a review of recent literature and practical applications

Since the publication of the Agency for Health Care Policy and Research Guidelines for treatment of heart failure, a number of new agents have been investigated for this indication. beta-Blockers have now been shown to improve outcomes in mild to moderate heart failure when added to standard therapy. Angiotensin II receptor antagonists have also been investigated and show promise. In general, calcium channel blockers are second- or third-line agents in patients refractory to other therapy. Investigational agents including spironolactone may also hold promise for future therapy.

The role of organic nitrates in the treatment of heart failure

Nitrates have been widely used in the treatment of patients with chronic congestive heart failure. Although the use of these drugs has not been approved by the Food and Drug Administration, multiple studies have shown their favorable effects. Organic nitrates have been shown to have a beneficial effect on ischemia, hemodynamic profile, magnitude of a mitral regurgitation, endothelial function, and cardiac remodeling. These drugs, when used in combination with hydralazine, have improved exercise capacity and survival. Recent studies have shown that the use of nitrates in patients already treated with standard heart failure therapy, including angiotensin converting enzyme (ACE) inhibitors, resulted in hemodynamic improvement, marked enhancement of exercise tolerance, reduction of left ventricular size, and augmentation of systolic function. These data suggest a role for organic nitrates as an adjunctive therapy to ACE inhibitors in patients with chronic heart failure and for nitrates in combination with hydralazine as an alternative treatment in patients who are intolerant to ACE inhibitors.