The prevention of heart failure--a new agenda

Prevalence and Prognostic Value of Heart Failure Stages: An Elderly Inpatient Based Cohort Study

Background: The prevalence and prognostic value of heart failure (HF) stages among elderly hospitalized patients is unclear.

Methods: We conducted a prospective, observational, multi-center, cohort study, including hospitalized patients with the sample size of 1,068; patients were age 65 years or more, able to cooperate with the assessment and to complete the echocardiogram. Two cardiologists classified all participants in various HF stages according to 2013 ACC/AHA HF staging guidelines. The outcome was rate of 1-year major adverse cardiovascular events (MACE). The Kaplan–Meier method and Cox proportional hazards models were used for survival analyses. Survival classification and regression tree analysis were used to determine the optimal cutoff of N-terminal pro-brain natriuretic peptide (NT-proBNP) to predict MACE.

Results: Participants' mean age was 75.3 ± 6.88 years. Of them, 4.7% were healthy and without HF risk factors, 21.0% were stage A, 58.7% were stage B, and 15.6% were stage C/D. HF stages were associated with worsening 1-year survival without MACE (log-rank χ² = 69.62, P < 0.001). Deterioration from stage B to C/D was related to significant increases in HR (3.636, 95% CI, 2.174–6.098, P < 0.001). Patients with NT-proBNP levels over 280.45 pg/mL in stage B (HR 2; 95% CI 1.112–3.597; P = 0.021) and 11,111.5 pg/ml in stage C/D (HR 2.603, 95% CI 1.014–6.682; P = 0.047) experienced a high incidence of MACE adjusted for age, sex, and glomerular filtration rate.

Conclusions : HF stage B, rather than stage A, was most common in elderly inpatients. NT-proBNP may help predict MACE in stage B.

Trial Registration: ChiCTR1800017204; 07/18/2018.

[Diabetes and heart failure]

Heart failure is a common complication of type 2 diabetes and bears a poor prognosis. For patients with diabetes and heart failure the commonly accepted standards for diagnosis and treatment of heart failure are to be applied, although prospective diabetes- specific trials are lacking. The optimum HbA(1c) target value as well as the optimum blood glucoselowering treatment are not known. Due to an absence of prospective randomized trials the treatment should follow general therapeutic principles (low incidence of side effects, combination therapy, patient-friendly dosage, costs).

Clinical evaluation of imidapril in congestive heart failure in dogs: results of the EFFIC study

OBJECTIVES

The clinical efficacy and safety of imidapril were evaluated in dogs that presented with mild to severe congestive heart failure (New York Heart Association stage II to IV) by comparing the success rate of imidapril with a positive control by a non-inferiority approach.

METHODS

This good, clinical practice compliant, multicentre study (EFFIC study) enrolled 142 client-owned dogs and was conducted in 20 locations in France, Belgium and Germany. Dogs of various breed, age and weight were included in the study. These dogs were randomised into two groups that were treated for 84 days with either the test product, imidapril, or the positive control, benazepril, and followed up in parallel over this period. Both treatments were administered at a dose of 0.25 mg/kg once a day with the possibility of doubling this dose to 0.5 mg/kg if considered necessary from a clinical point of view. In addition, concomitant treatment was given to dogs presenting with pulmonary oedema and/or ascites, supraventricular tachyarrhythmia and/or dilated cardiomyopathy. The evolution of the New York Heart Association stage and the "functional signs" score were evaluated as primary efficacy criteria.

RESULTS

The success rate in the imidapril group was 66 compared with 68 per cent in the benazepril group. Regarding safety, 35 dogs in each group experienced at least one adverse event. Nine dogs in each group experienced at least one serious adverse event. The difference between these results was not statistically significant.

CLINICAL SIGNIFICANCE

Imidapril is as efficacious and safe as the reference product, benazepril.

Prevalence and prognostic significance of heart failure stages: application of the American College of Cardiology/American Heart Association heart failure staging criteria in the community

BACKGROUND

Heart failure (HF) is a progressive disorder associated with frequent morbidity and mortality. An American Heart Association/American College of Cardiology staging classification of HF has been developed to emphasize early detection and prevention. The prevalence of HF stages and their association with mortality are unknown. We sought to estimate HF stage prevalence in the community and to measure the association of HF stages with mortality.

METHODS AND RESULTS

A population-based, cross-sectional, random sample of 2029 Olmsted County, Minnesota, residents aged > or = 45 years was identified. Participants were classified by medical record review, symptom questionnaire, physical examination, and echocardiogram as follows: stage 0, healthy; stage A, HF risk factors; stage B, asymptomatic cardiac structural or functional abnormalities; stage C, HF symptoms; and stage D, severe HF. In the cohort, 32% were stage 0, 22% stage A, 34% stage B, 12% stage C, and 0.2% stage D. Mean B-type natriuretic peptide concentrations (in pg/mL) increased by stages: stage 0=26, stage A=32, stage B=53, stage C=137, and stage D=353. Survival at 5 years was 99% in stage 0, 97% in stage A, 96% in stage B, 75% in stage C, and 20% in stage D.

CONCLUSIONS

The present study provides prevalence estimates and prognostic validation for HF staging in a community cohort. Of note, 56% of adults > or = 45 years of age were classified as being in stage A (risk factors) or B (asymptomatic ventricular dysfunction). HF staging underscores the magnitude of the population at risk for progression to overt HF.

A review of calcium channel antagonists in the treatment of pediatric hypertension

All children aged > or = 3 years should have an annual blood pressure (BP) measurement taken during a routine physical examination. Physicians should become familiar with recommended pediatric normative BP tables. BP above the 95th percentile may require drug therapy. There are several categories of antihypertensives available to the clinician. Calcium channel antagonists (CCAs) are a class of drugs that exert their antihypertensive effect by inhibiting the influx of calcium ions across the cell membranes. This results in dilatation of peripheral arterioles. When given orally, CCAs are metabolised in the liver by cytochrome P450 (CYP) enzyme CYP3A4; hence, some CCAs will affect the half-life of drugs that share this enzyme system for their metabolism. CCAs can be safely used in children with renal insufficiency or failure and as a general rule there is no need to modify drug dosage in this population. CCAs are generally well tolerated; most adverse effects appear to be dose related. Headache, flushing, gastrointestinal upset, and edema of the lower extremities are the most common symptoms reported with the use of CCAs. Pediatric data regarding safety and efficacy of CCAs have mostly been obtained from retrospective analyses. Extended-release nifedipine and amlodipine are the two most commonly used oral CCAs in the management of pediatric hypertension. These drugs can be given once a day, although many children require twice-daily administration. Extended-release nifedipine has to be swallowed whole; hence, its use in younger children who cannot swallow pills is limited. Amlodipine can be made into a solution without compromising its long duration of action; therefore, it is the CCA of choice for very young children. Oral short-acting nifedipine and intravenous nicardipine are safe and effective CCAs for the management of hypertensive crisis in children. Short-acting nifedipine can cause unpredictable changes in BP; hence, it should be used cautiously and in low doses. Intravenous nicardipine has a rapid onset of action and a short half-life. Intravenous infusion of nicardipine can be titrated for effective control of BP. Intravenous nicardipine has been used safely in hospitalized children and newborns for the management of hypertensive crisis, and for controlled hypotension during surgery. CCAs are a class of antihypertensives that are safe and effective in pediatric patients. They have relatively few adverse effects and are well tolerated by children. This article reviews CCAs as antihypertensives in the management of pediatric hypertension.

Altered blood pressure responses and normal cardiac phenotype in ACE2-null mice

The carboxypeptidase ACE2 is a homologue of angiotensin-converting enzyme (ACE). To clarify the physiological roles of ACE2, we generated mice with targeted disruption of the Ace2 gene. ACE2-deficient mice were viable, fertile, and lacked any gross structural abnormalities. We found normal cardiac dimensions and function in ACE2-deficient animals with mixed or inbred genetic backgrounds. On the C57BL/6 background, ACE2 deficiency was associated with a modest increase in blood pressure, whereas the absence of ACE2 had no effect on baseline blood pressures in 129/SvEv mice. After acute Ang II infusion, plasma concentrations of Ang II increased almost 3-fold higher in ACE2-deficient mice than in controls. In a model of Ang II-dependent hypertension, blood pressures were substantially higher in the ACE2-deficient mice than in WT. Severe hypertension in ACE2-deficient mice was associated with exaggerated accumulation of Ang II in the kidney, as determined by MALDI-TOF mass spectrometry. Although the absence of functional ACE2 causes enhanced susceptibility to Ang II-induced hypertension, we found no evidence for a role of ACE2 in the regulation of cardiac structure or function. Our data suggest that ACE2 is a functional component of the renin-angiotensin system, metabolizing Ang II and thereby contributing to regulation of blood pressure.

The role of brain natriuretic peptide in population screening

While measurement of plasma BNP concentration has been shown to be useful in the diagnosis of heart failure, its role as a screening test for detection of pre-clinical ventricular remodeling or dysfunction in the general population has not been established. Here we review available population-based studies assessing the predictive characteristics of BNP for the detection of pre-clinical structural heart disease (Stage B Heart Failure).

The Ets-1 transcription factor is involved in the development and invasion of malignant melanoma

The Ets-1 transcription factor plays a role in tumor vascularization and invasion by regulating expression of matrix-degrading proteases in endothelial cells and fibroblasts in the tumor stroma. During early embryogenesis, Ets-1 is expressed in migrating neural crest cells from which melanocytes arise. In the present study, we analyzed Ets-1 expression in various melanocytic lesions and investigated its functional importance in malignant melanomas. We found that Ets-1 was upregulated both in vivo and in vitro in malignant melanoma, compared to benign melanocytic lesions and to primary melanocytes. Assessment of DNA-binding and transactivation assays documented a strong Ets activity in melanoma cells. Using an antisense strategy, the expression and activity of Ets-1 were reduced in the melanoma cell line Mel Im. This correlated with a diminished expression of several Ets-1 target genes known to be involved in invasion, such as MMP1, MMP3, uPA and integrin beta3. In line with these findings, the invasive potential of the melanoma cells measured in a Boyden Chamber model was reduced up to 60% after Ets-1 blockade. This can be attributed to the role of Ets-1 in transcriptional regulation of factors involved in invasion of melanoma cells. We conclude that over-expression of Ets-1 during melanoma development contributes to the malignant phenotype.

Vasopeptidase inhibitors

Vasopeptidase inhibitors are a new class of cardiovascular drug that simultaneously inhibit both neutral endopeptidase and angiotensin-converting enzyme (ACE). They increase the availability of peptides that have vasodilatory and other vascular effects; they also inhibit production of angiotensin II. In animal models vasopeptidase inhibitors decrease blood pressure in low, medium, and high renin forms of hypertension, and they also appear to confer benefits in models of heart failure and ischaemic heart disease. Studies in human hypertension show that these agents are effective in decreasing blood pressure regardless of race or age. Experience with omapatrilat, the most clinically advanced of these drugs, has shown it to be more effective than currently available ACE inhibitors or other widely used antihypertensive agents. Studies with omapatrilat in congestive heart failure have shown beneficial effects on haemodynamics and symptoms. The vasopeptidase inhibitors appear to have safety profiles similar to ACE inhibitors, though the frequency of side-effects such as angio-oedema and cough remains to be established. Large trials with clinical endpoints, some already in progress, are needed to establish the place of this class of drug beside that of established therapies in conditions such as hypertension, heart failure, ischaemic heart disease, and nephropathy.

Assessment of brain natriuretic peptide in patients with suspected heart failure: comparison with radionuclide ventriculography data

BACKGROUND

The aim of the study was to prospectively evaluate patients with suspected or known heart disease using plasma brain natriuretic peptide (BNP) measurement and radionuclide ventriculography to examine whether left ventricular dysfunction is associated with an abnormal rise of BNP concentration.

METHODS

Patients (n=153) and controls (n=14) underwent radionuclide ventriculography to determine Left ventricular Ejection Fraction (LVEF) and measurement of plasma BNP concentration using a commercial kit.

RESULTS

Plasma BNP concentration in controls was significantly lower than that in patients whatever the stage of the disease, significantly lower than that of patients with normal LVEF (LVEF>55%); than that of patients with altered LVEF (LVEF< or =40%); and than that of patients with moderately reduced LVEF (40%<LVEF< or =5%). Comparisons between groups of patients showed that the more severe the disease, the higher the BNP level. From the ROC curve, a plasma BNP concentration of 52 pg/ml was attached to a 85% sensitivity and 82% specificity in identifying patients with LVEF< or =40%.

CONCLUSIONS

Plasma BNP concentration provides a reliable and sensitive marker of LV systolic dysfunction evaluated by a nuclear medicine technique, and could be a potential screening test to identify patients for additional investigations.

Clinical criteria and biochemical markers for the detection of systolic dysfunction

BACKGROUND

This study was designed to assess the use of clinical criteria and biochemical testing to detect systolic dysfunction. Our goal is to develop strategies that may enhance the detection and treatment of patients with early ventricular dysfunction while reducing the use of echocardiography.

METHODS AND RESULTS

We compared the predictive characteristics of the plasma brain natriuretic peptide (BNP) concentration with that of a 5-point clinical score derived from elements of the history, electrocardiogram, and chest radiograph in outpatients (n = 466) referred for echocardiography because of symptoms of heart failure or risk factors for systolic dysfunction. Systolic dysfunction was defined as an ejection fraction (EF) less than 45% and was present in 10.9% of patients. By receiver operating characteristic analysis, BNP was sensitive and specific for the detection of systolic dysfunction, with an area under the receiver operating characteristic curve for the detection of EF less than 45% of 0.79. The BNP assay was abnormal in 41% of patients and identified a group with a high prevalence of systolic dysfunction (21% with an EF less than 45%), whereas a normal BNP value identified a group with a low prevalence of systolic dysfunction (4% with an EF less than 45%). The clinical score was positive in 43% of the population and identified a group with a high prevalence of systolic dysfunction (24% with an EF less than 45%). A normal score identified a group with a low prevalence of systolic dysfunction (1% with an EF less than 45%).

CONCLUSION

This study supports previous studies, which showed that BNP assay predicts systolic dysfunction with acceptable sensitivity and specificity, and it underscores the effectiveness of additional readily available clinical criteria. Both of these strategies should be considered in screening for left ventricular dysfunction in populations at risk while limiting expensive cardiac imaging modalities.

Influence of angiotensin on the early progression of heart failure

The purpose of this study was to elucidate the role of circulating ANG II in mediating changes in systemic and renal hemodynamics, salt and water balance, and neurohormonal activation during the early progression of heart failure. This objective was achieved by subjecting six dogs to 14 days of rapid ventricular pacing (240 beats/min) while fixing plasma ANG II concentration (by infusion of captopril + ANG II) either at approximately normal (days 1-8, 13-14) or at high physiological (days 9-12) levels. Salt and water retention occurred during the initial days of pacing before sodium and fluid balance was achieved by day 8. At this time, cardiac output and mean arterial pressure were reduced to approximately 55 and 75% of control, respectively; compared with cardiac output, reductions in renal blood flow were less pronounced. Although plasma ANG II concentration was maintained at approximately normal levels, there were sustained elevations in total peripheral resistance (to approximately 135% of control), filtration fraction (to approximately 118% of control), and plasma norepinephrine concentration (to 2-3 times control). During the subsequent high rate of ANG II infusion on days 9-12, there were no additional sustained long-term changes in either systemic or renal hemodynamics other than a further rise in right atrial pressure. However, high plasma levels of ANG II induced sustained antinatriuretic, sympathoexcitatory, and dipsogenic responses. Because these same long-term changes occur in association with activation of the renin-angiotensin system during the natural evolution of this disease, these results suggest that increased plasma levels of ANG II play a critical role in the spontaneous transition from compensated to decompensated heart failure.

Myocardial tumor necrosis factor-alpha secretion in hypertensive and heart failure-prone rats

Acute increases in blood pressure (BP) increase myocardial tumor necrosis factor (TNF)-alpha production, but it is not known whether chronic hypertensive stress elevates myocardial TNF-alpha production, possibly contributing to cardiac remodeling, decreased cardiac function, and faster progression to heart failure. BP, cardiac function, and size were evaluated in normotensive [Sprague-Dawley (SD)], spontaneously hypertensive (SHR), and spontaneously hypertensive heart failure-prone (SHHF) rats at 6, 12, 15, and 18 mo of age and in failing SHHF. Left ventricular tissues were evaluated for secretion of bioactive TNF-alpha and inhibition of TNF-alpha secretion by phosphodiesterase inhibitors. All ventricles secreted bioactive and immunoreactive TNF-alpha, but secretion decreased with age. SHR and SHHF rats secreted more TNF-alpha than SD rats at 6 mo of age, but only failing SHHF rats secreted significantly more TNF-alpha at 18 mo. Amrinone inhibited TNF-alpha secretion in all rats and was less potent but more efficacious than RO-201724 in all strains. TNF-alpha secretion correlated with BP and left ventricular mass in 6-mo-old rats, but this relationship disappeared with age. Results suggest that hypertension and/or cardiac remodeling is associated with elevated myocardial TNF-alpha, and, although hypertension, per se, did not maintain elevated cardiac TNF-alpha levels, SHHF rats increase TNF-alpha production during the end stages of failure.

Information needs in a changing health care system: capitation and the need for a population-oriented view

Information systems needed for managing the health care of populations under at-risk (capitation) contracts must be designed differently than those used in fee-for-service practice. Under capitation, providers must deliver health care to enrollees with financial resources that are fixed in advance. Therefore, the information systems they use must enable them to understand the health status of health plan enrollees and how health care is provided. These systems should facilitate the detection of underservice and of inadequate quality of health care as well as overuse of health care resources. They should permit clinical-epidemiologic and statistical analysis; facilitate disease management and the adoption of preventive programs, and lend themselves to use by planners, group leaders, and practicing physicians.

Blood pressure response to the first 36 hours of heart failure therapy with perindopril versus captopril. French General Hospitals National College of Cardiologists

An open randomized hospital study conducted in 169 centers in France compared the blood pressure response to the first 36 h of treatment with perindopril (PER), 2 mg once daily, with that to captopril (CAP), 6.25 mg t.i.d., in 725 patients (mean age, 70 years; men, 67%) with echocardiographic left ventricular systolic dysfunction (fractional shortening, < or = 28%) due to ischemia (56.7%) or hypertension (34.5%) and a systolic blood pressure (SBP) > or = 120 mm Hg. Each dose of CAP induced a sharp and rapid decrease in blood pressure (maximum, 1.5-2 h); with PER, the decrease was gradual (maximum, 6 h) and variation was less marked. However, at 36 h, the decrease in blood pressure versus baseline was similar on both treatments. Over the 36-h period, there were 22 (3%) dropouts due to marked orthostatic hypotension (SBP, <90 mm Hg), and they were fewer with PER than with CAP: 16 cases in the CAP group versus six in the PER group (p = 0.036). At 36 h, heart rate was lower with CAP than with PER: 75.2 versus 77.5 beats/min, respectively (p = 0.039). As initial therapy for stabilized left ventricular systolic dysfunction, the first dose of PER (2 mg) induced a significantly smaller decrease in blood pressure than the first dose of CAP (6.25 mg); dropouts due to orthostatic hypotension were also significantly fewer with PER than with CAP.

Secondary prevention of myocardial infarction: role of beta-adrenergic blockers and angiotensin-converting enzyme inhibitors

beta-Blockers reduce cardiovascular death and reinfarction in patients with a history of myocardial infarction (MI), and angiotensin-converting enzyme (ACE) inhibitors provide an overall survival benefit in patients with signs or symptoms of left ventricular (LV) dysfunction and a history of acute MI. Despite this, these agents remain underused in clinical practice. Appropriate patient selection in standard clinical practice should be encouraged in order to achieve a mortality rate reduction comparable to that seen in clinical trials. It appears from the findings of recent studies that the greatest benefit from beta-blocker therapy is achieved in patients who are more than 60 years of age and in patients at moderate or high risk for reinfarction and death (eg, patients with LV dysfunction or arrhythmias or both). Patients with class I-IV heart failure treated with ACE inhibitors have fewer recurrent infarctions, a lower incidence of severe congestive heart failure, and a reduced incidence of total cardiovascular death and sudden cardiac death. In addition to the studies completed in patients with MI, there are ongoing studies evaluating whether or not ACE inhibitors can reduce myocardial ischemic events in patients without a prior infarction who have coronary artery disease or hypertension and preserved LV function. There is also growing evidence that concomitant therapy with a beta-blocker and an ACE inhibitor may reduce mortality rates beyond that observed with ACE inhibitors alone in survivors of MI who have LV dysfunction.

Comparison of type 1 angiotensin II receptor blockers and angiotensin converting enzyme inhibitors in the treatment of hypertension

RENIN-ANGIOTENSIN SYSTEM AND HYPERTENSION: The renin-angiotensin system is integral to the mechanisms that sustain hypertension. Hypertensive patients with inappropriately high renin levels have an increased risk of cardiovascular events, and thus there is continuing interest in treating hypertension with drugs that not only reduce blood pressure but also have an inhibitory effect on the renin-angiotensin system. INHIBITORS OF THE RENIN-ANGIOTENSIN SYSTEM: Angiotensin converting enzyme (ACE) inhibitors decrease blood pressure and ameliorate the symptoms of congestive heart failure. Drugs that selectively block the AT1 angiotensin II receptor are now entering clinical practice for the treatment of hypertension and, very likely, congestive heart failure. PHARMACOLOGIC DIFFERENCES: There are some important theoretical differences between ACE inhibitors and AT1 blockers in their actions on the renin-angiotensin system. ACE inhibitors ostensibly prevent the formation of angiotensin II. However, this action is far from complete, as measurable plasma concentrations of ACE remain during chronic therapy with these agents. AT1 receptor blockers work selectively at the AT1 receptor, leaving the AT2 receptor unaffected. The importance of this selectivity has not yet been established, but AT2 receptors are thought to mediate inhibitory effects on growth. It has been postulated that the selective blockade by this new class of drugs will directly decrease the growth-promoting actions of angiotensin II at the AT1 receptor, while leaving the growth-inhibitory effects of the AT2 receptor unaffected. The clinical relevance of these differing pharmacologic properties of ACE inhibitors and AT1 blockers have not yet been established. BLOOD PRESSURE, METABOLIC AND RENAL EFFECTS: AT1 receptor blockers appear to have relatively high trough:peak efficacy ratios compared with ACE inhibitors. However, in patients with essential hypertension compared with normal volunteers, the M value, a measure of glucose clearance and insulin sensitivity, is reduced. Both the ACE inhibitor delapril and the AT1 blocker candesartan have shown a beneficial effect on insulin sensitivity, and candesartan appears to restore the M value to normal. While ACE inhibitors have been shown to have strongly beneficial actions in the kidneys, comparable data are not yet available for AT1 blockers.

SIDE EFFECTS

The relatively common problem of cough observed with ACE inhibitors does not occur with AT1 blockers.

FUTURE WORK

Future studies must address metabolic and cardiovascular questions that have not yet been answered. It will also be of interest to determine whether the combination of AT1 blockers and ACE inhibitors, especially in more resistant forms of congestive heart failure or hypertension, might confer additive benefits.

Comparison of captopril and ibopamine in mild to moderate heart failure

OBJECTIVE

To determine the effects of ibopamine 100 mg three times daily compared with captopril 25 mg three times daily on exercise capacity in patients with chronic heart failure.

DESIGN

A randomised, double blind, parallel group comparison of the addition of ibopamine versus captopril during a period of 24 weeks.

SETTING

26 outpatient cardiology clinics in seven European countries.

PATIENTS

266 patients, with mild to moderate chronic heart failure (New York Heart Association (NYHA) functional class II, 81% and III, 19%) and evidence of an enlarged left ventricle. Patients received concomitant treatment with diuretics and/or digitalis.

MAIN OUTCOME MEASURE

Exercise duration after 24 weeks of treatment, compared with baseline.

RESULTS

Mean (SD) ejection fraction was 29 (8)% and the baseline exercise duration in the captopril and ibopamine groups 665 (160) and 675 (174) seconds, respectively. At the end of the study, exercise duration had improved in both groups, by 29 seconds in the ibopamine group (P < 0.01), and by 24 seconds in the captopril group (P < 0.05). There was no difference between groups (P = 0.69, 95% confidence interval -22 to 33). NYHA class, signs and symptoms score, and dyspnoea and fatigue index improved equally in both groups. The total number of adverse events was the same in both treatment groups, but gastrointestinal complaints occurred more often in the ibopamine group. The number of patients with premature withdrawals was no different.

CONCLUSIONS

No difference was detected between the effect of captopril and ibopamine on exercise time in patients with mild to moderate heart failure during a treatment period of 24 weeks.

Current and newer approaches in the drug treatment of congestive heart failure

Most patients with chronic congestive heart failure (CHF) are subjected to symptomatic treatment, predominantly with drugs. Over the years, it has become clear that treatment with unloading drugs is probably more beneficial than treatment with inotropic agents. In addition, it has been widely recognized that the neuroendocrine compensatory changes associated with CHF afford and important target for drug treatment. This may also hold for some of the changes in receptor density, such as the downregulation of cardiac beta-adrenoceptors. The present and clearly changing insights into the backgrounds of drugs for the treatment of CHF are critically discussed. Apart from the changing views and appreciation of the currently used drugs (diuretics, ACE inhibitors, digoxin, beta-adrenoceptor agonists), the following new approaches are discussed: beta-blockers, angiotensin II receptor antagonists, ibopamine, calcium antagonists, inhibitors of ANP degradation, vasopression antagonist, vesnarinone, and calcium sensitizers.

Superiority of brain natriuretic peptide as a hormonal marker of ventricular systolic and diastolic dysfunction and ventricular hypertrophy

Atrial and brain natriuretic peptides (ANP and BNP) are produced by the heart, and their plasma concentrations are increased in human chronic congestive heart failure. Although separate studies have suggested that circulating levels of the biologically active C-terminal ANP, the biologically inactive N-terminal ANP, and BNP may have diagnostic utility in the detection of left ventricular systolic dysfunction or left ventricular hypertrophy, no studies have directly assessed the relative value of these peptides prospectively. We therefore designed this study to compare the relative ability of the different natriuretic peptides to detect abnormal left ventricular systolic and diastolic function and left ventricular hypertrophy. Using a prospective study design, we investigated 94 patients referred for cardiac catheterization and 15 age-matched normal subjects. The diagnostic abilities of elevated plasma C-terminal ANP, N-terminal ANP-(1-30), and BNP concentrations to identify systolic dysfunction (ejection fraction < 45%), diastolic dysfunction (time constant of left ventricular relaxation > 55 milliseconds, left ventricular end-diastolic pressure > 18 mm Hg), and left ventricular hypertrophy (left ventricular mass index > 120 g/m2) were objectively compared by receiver operating characteristic analysis. The areas under the receiver operating characteristic curve of BNP for detecting each of these abnormalities ranged from 0.715 to 0.908 and were significantly greater than those of C-terminal ANP or N-terminal ANP-(1-30). The sensitivity and specificity of an elevated plasma BNP, which we defined as greater than the mean + 3 SD of the 15 age-matched normal subjects, were 0.83 and 0.77, respectively, for detecting ejection fraction less than 45%, 0.85 and 0.70 for detecting the time constant of left ventricular relaxation greater than 55 milliseconds, 0.63 and 0.76 for detecting left ventricular end-diastolic pressure greater than 18 mm Hg, and 0.81 and 0.85 for detecting left ventricular mass index greater than 120 g/m2. The use of BNP and one other peptide increased sensitivity (0.90 to 0.96), albeit with lower specificity (0.56 to 0.71). An elevated plasma BNP was a more powerful marker of left ventricular systolic dysfunction, left ventricular diastolic dysfunction, and left ventricular hypertrophy than C-terminal ANP or N-terminal ANP-(1-30) in this population of patients with suspected cardiac disease. Measurement of BNP alone or in combination with C-terminal ANP or N-terminal ANP-(1-30) has potential utility for the detection of altered left ventricular structure and function in a patient population at risk for cardiovascular disease.

EITS changes following oleic acid induced lung water

We present the results of using electrical impedance tomographic spectroscopy (EITS) to follow the changes in lung water induced by oleic acid. Measurements were made on three goats before and after the injection of oleic acid. In addition to the EITs measurements, lung water was also measured using a double-indicator technique. Large falls in lung electrical impedance were seen as a result of the increase in lung water but the size of the fall was a function of the frequency at which the measurements were made. These changes have been modelled using the Cole equation. Four-electrode measurements were also made on two extracted porcine lungs and Cole equation modelling carried out following the introduction of saline into the lungs. Results were similar in the two sets of animal experiments.

Changing patterns of investigation and treatment of cardiac failure in hospital

OBJECTIVE

To assess the investigation and treatment of cardiac failure in 1995 and to compare this with management in 1992.

DESIGN

Retrospective consecutive case study.

SETTING

University teaching hospital.

SUBJECTS

All patients (n = 265) discharged from Aberdeen Royal Infirmary in the first quarter (January 1-31 March) of 1995 with a diagnosis of congestive cardiac failure, left ventricular failure, or heart failure (unspecified). These correspond to the International Classification of Diseases 9th revision codings of 428.0, 428.1, and 428.9 respectively.

METHODS

Sociodemographic and clinical data were extracted from the case notes of the above subjects and compared with similar data from the final six months of 1992.

MAIN OUTCOME MEASURES

The use of echocardiography in confirming the diagnosis and delineating the aetiology of heart failure and the use of angiotensin-converting enzyme (ACE) inhibitors in the treatment of patients diagnosed as having heart failure and without contraindications to these agents.

RESULTS

The number of patients discharged in 1995 with a diagnosis including cardiac failure had increased by 55.7% since 1992. The use of echocardiography had also risen from 36.6% to 72% (P < 0.0001) with an associated increase in the proportion of patients discharged on treatment with an ACE inhibitor (40% in 1992 v 55.1% in 1995: P < 0.001). The doses of ACE inhibitors used had also increased significantly (P < 0.001). Most patients with cardiac failure continue to be treated by general physicians, who are less likely to use echocardiography (P < 0.01) or prescribe an ACE inhibitor (P < 0.05) than cardiologists.

CONCLUSIONS

There is increasing recognition, more thorough investigation, and improved treatment of heart failure. Despite this there are grounds for concern, both in terms of the adequacy of management and resource implications.

Effects of myocardial infarction and captopril therapy on anxiety-related behaviors in the rat

The angiotensin-converting enzyme inhibitor, captopril, is used in the treatment of heart failure after myocardial infarction. This study evaluated whether different behavioral parameters of anxiety are affected by captopril therapy after myocardial infarction in rats. Myocardial infarction was induced by ligation of the left coronary artery and captopril therapy was started after 3 weeks. After 2 weeks of captopril therapy, anxiety-related behaviors were successively measured in four different tests: open field, elevated plus maze, home cage emergence, and open field escape. Myocardial infarction and captopril therapy affected behavior in the home cage emergence test and open field escape test. On the basis of the data from the open field escape test, captopril therapy appeared to decrease anxiety in infarcted rats and increase anxiety in sham rats. Because myocardial infarction and captopril therapy did not affect anxiety-related behaviors in the open field and elevated plus maze tests, it is assumed that these interventions affect anxiety-related behaviors depending on the type of test. This was partially supported by correlation analysis, which suggested that the behavior of the rats in the different tests of anxiety may reflect different anxiety-related traits.

[Current status of treatment of chronic cardiac insufficiency]

When there is no correctable cause, cardiac failure continues to progress and outcome is poor. However several controlled clinical trials have shown that several therapeutic agents relieve symptoms, improve exercise tolerance and, for some, reduce mortality. Patients in NYHA functional class II, III and IV, whose systolic function is impaired should be treated by digitalis, diuretics and angiotensin-converting-enzyme inhibitors. These therapeutic agents are complementary and each of them are required. Moreover a study has shown that the impairment of patients in NYHA functional class I (who are still asymptomatic but with a ventricular ejection fraction < 35%) could be slowed by angiotensin-converting-enzyme inhibitors. In each case, it is of paramount importance to exclude treatable causes of heart failure because the best the symptomatic treatment can do is slow the inevitable worsening of the disease.

Effects of lacidipine on peak oxygen consumption, neurohormones and invasive haemodynamics in patients with mild to moderate chronic heart failure

OBJECTIVE

To evaluate the efficacy and safety of the second generation dihydropyridine calcium channel blocker lacidipine in patients with heart failure.

DESIGN

Placebo controlled, parallel group, double blind study over 8 weeks.

SETTING

General community hospital in Breda, The Netherlands.

PATIENTS

A random sample was studied of 25 outpatients with symptoms of mild to moderate heart failure, despite treatment with diuretics, digoxin, and angiotensin converting enzyme inhibitors. Their mean age was 65 years, with mean left ventricular ejection fraction of 0.24 and a peak oxygen consumption of 14.4 ml/min/kg. Two patients dropped out on lacidipine, one patient on placebo.

INTERVENTION

Treatment with lacidipine 4 mg once daily or placebo for eight weeks.

MAIN OUTCOME MEASURE

Cardiopulmonary exercise testing, invasive haemodynamics, and plasma neurohormones.

RESULTS

Treatment with lacidipine 4 mg once daily, as compared to placebo treatment, significantly improved peak oxygen consumption (P < 0.02), cardiac index (P < 0.01), and stroke volume (P < 0.03) paralleled by a decrease in systemic vascular resistance (P < 0.03) and arteriovenous oxygen content difference (P < 0.01). Plasma noradrenaline, plasma renin activity, and aldosterone values did not differ between lacidipine and placebo.

CONCLUSIONS

This second generation dihydropyridine may be of value as an adjunct to standard treatment in congestive heart failure patients.

Exploration of the precision of classifying sudden cardiac death. Implications for the interpretation of clinical trials

BACKGROUND

As cardiovascular clinical trials improve in sophistication and therapies target specific cardiac mechanisms of death, a more objective and precise system to identify specific cause of death is needed. Ideally, sudden cardiac death would describe patients dying of ventricular tachycardia and ventricular fibrillation. In this context, we explored the precision of current sudden death classification and implications for clinical trials.

METHODS AND RESULTS

Deaths were analyzed in 834 patients who received an automatic implantable cardioverter-defibrillator (ICD). Three arrhythmia experts used a standard prospective classification system to classify deaths into accepted categories: sudden cardiac, nonsudden cardiac, and noncardiac. New aspects to this study included analysis of autopsy results and ICD interrogation for arrhythmias at the time of death. All of the patients receiving the ICD previously had documented sustained ventricular tachycardia/fibrillation or cardiac arrest. Of the 109 subsequent deaths in the 834-patient database, 17 (16%) were classified as sudden cardiac. Compared with the nonsudden cardiac and noncardiac categories, sudden cardiac death was more often identified in outpatients (59% versus 10%) and witnessed less often (41% versus 86%; both P < .001). The autopsy information contradicted and changed the clinical perception of a "sudden cardiac death" in 7 cases (myocardial infarction [n = 1], pulmonary embolism [n = 2], cerebral infarction [n = 1], ruptured thoracic [n = 1], and abdominal aortic aneurysms [n = 2]). Interpretable ICD interrogation was available in 53% of the deaths (47% unavailable: buried, programmed off, or other technical reasons). When evaluated, only 7 of 17 "sudden deaths" were associated with ICD discharges near the time of death.

CONCLUSIONS

Even in a group of patients with an ICD, deaths classified as sudden cardiac frequently were not associated with ventricular tachycardia or ventricular fibrillation and were often noncardiac. It is possible to create a wide range of sudden cardiac death rates (more than fourfold) using the identical clinical database despite objective, prespecified criteria. Autopsy results frequently reveal noncardiac causes of clinical events simulating sudden cardiac death. ICD interrogation revealed that ICD discharges were often related to terminal arrhythmias incidental to the primary pathophysiological process leading to death.

Effect of low dose Amiodarone on the incidence of sudden death in elderly patients with congestive heart failure: a double-bind, placebo-controlled study

To determine if low-dose Amiodarone could reduce sudden death (SD) among patients with congestive heart failure, a prospective, double-blind, placebo-controlled study was conducted. The study group consisted of 46 patients (36 men and 10 women, mean age 71 +/- 5 years) with complex ventricular ectopy documented by 48-hour Holter monitoring. Randomization divided the patients into two treatment groups: the first group received Amiodarone (400 mg/day for 1 week and then 100 mg/day), while the second group received placebo. The drug significantly reduced ventricular arrhythmias, but then was no decrease in incidence of SD. This study demonstrates not only that low-dose Amiodarone can be safely administered to elderly patients with congestive heart failure and it will significantly suppress ventricular arrhythmias, but also that reduction in ventricular arrhythmias and the risk of SD are not linearly related.

Dose-dependent dissociation of ACE-inhibitor effects on blood pressure, cardiac hypertrophy, and beta-adrenergic signal transduction

BACKGROUND

Dose-dependent effects of ACE inhibitors on blood pressure, cardiac hypertrophy, and beta-adrenergic signal transduction were examined in an animal model with beta-adrenergic desensitization, which has been identified in failing hearts and in hypertensive cardiac hypertrophy. It is unknown whether beneficial ACE-inhibitor effects are due to an unloading of the failing heart or a reduction of neuroendocrine activation with beta-adrenergic resensitization.

METHODS AND RESULTS

Low-dose (LD, 1 mg/kg) and high-dose (HD, 25 mg/kg) fosinopril treatment was performed in spontaneously hypertensive rats (SHR) and control (WKY) rats. Myocardial norepinephrine concentrations, adenylyl cyclase activity, beta-adrenergic receptors (radioligand binding), Gs alpha (functional reconstitution), and Gi alpha (pertussis toxin labeling) were determined. Ventricular weights and blood pressures were measured. HD but not LD reduced blood pressure and left ventricular weights in SHR. Isoprenaline- and guanylylim-idodiphosphate-stimulated adenylyl cyclase activities as well as beta 1-adrenergic receptors were reduced in SHR. The catalyst and Gs alpha were unchanged, but Gi alpha and norepinephrine concentrations were increased. Both LD and HD treatments restored beta-adrenergic alteration.

CONCLUSIONS

LD treatment with ACE inhibitors restored beta-adrenergic signal transduction defects independently of regression of cardiac hypertrophy. This could contribute to the effects of ACE inhibitors in patients, who are often treated with nonhypotensive doses.

Contemporary management of patients with heart failure

Treatment of patients with heart failure has become extremely challenging. A complicated interplay of myocardial, hemodynamic, and humoral factors marking this condition requires a delicate balancing of medication use, procedural intervention, and lifestyle changes. Judicious prescription of therapies in stepwise fashion as the syndrome severity worsens (Fig. 2) is critical to success.

Progression of mild untreated heart failure during six months follow-up and clinical and neurohumoral effects of ibopamine and digoxin as monotherapy. DIMT Study Group. Dutch Ibopamine Multicenter Trial

There is increasing evidence that clinical deterioration in manifest chronic heart failure is related to both hemodynamic and neurohumoral factors. Only few data are available, however, on the progression of disease in its early stages, when treatment has not yet been initiated. The aim of this study was therefore to examine the changes in clinical and neurohumoral variables that occur over 6 months in patients with clinically stable and untreated heart failure, and to evaluate the influence of drugs that may affect these variables. Accordingly, we studied 64 patients with heart failure who were in New York Heart Association functional class II (88%) and III (12%). They were randomized to double-blind treatment with the oral dopamine agonist ibopamine (100 mg 3 times daily; n = 22), digoxin (0.25 mg once daily; n = 22) or placebo (n = 20). Their age (mean +/- SD) was 60 +/- 8 years, and left ventricular ejection fraction (mean +/- SD) was 0.33 +/- 0.08. Of the 64 patients, 56 (88%) completed the 6-month study period (p = NS between groups). Exercise time decreased in patients treated with placebo after 6 months (median -62 seconds; p < 0.05 vs baseline), but it increased with ibopamine (+48 seconds), and digoxin (+17 seconds; both p < 0.05 vs placebo). Plasma norepinephrine increased in the placebo group after 6 months (median + 31 pg/ml, p < 0.05 vs baseline), but decreased in patients receiving active drug treatment (ibopamine: -24 pg/ml, digoxin: -98 pg/ml, both p < 0.05 vs placebo). Plasma renin and aldosterone levels were unchanged after 6 months in the placebo group, but digoxin therapy slightly reduced plasma renin concentration (-5 microU/ml; p < 0.05 vs placebo).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical efficacy of ibopamine in patients with chronic heart failure

Ibopamine, the most widely studied dopaminergic drug for the treatment of chronic heart failure, appears to have beneficial hemodynamic, renal, and neurohormonal effects in this setting. Angiotension-converting enzyme (ACE) inhibitors have become the recommended standard treatment for chronic heart failure; however, some patients may benefit from additional drugs to improve their symptoms and functional capacity. Ibopamine may be effective as an additive drug for patients with chronic heart failure. It is also possible that ibopamine will improve survival in these patients. Large-scale trials are needed to assess the effects on morbidity and mortality when ibopamine is added to ACE inhibitors, diuretics, and possibly digitalis.

Reduction of ischemic events with angiotensin-converting enzyme inhibitors: lessons and controversy emerging from recent clinical trials

Angiotensin-converting enzyme (ACE) inhibitor therapy has been associated with a substantial (> or = 20%) reduction in the risk of major ischemic events in two recent clinical trials with long-term follow-up: Studies of Left Ventricular Dysfunction (SOLVD) and the Survival and Ventricular Enlargement (SAVE) study. Participants in these studies included patients with a low ejection fraction (< or = 0.35 in SOLVD and < or = 0.40 in SAVE), generally without symptoms of congestive heart failure. Approximately 80% of patients enrolled in SOLVD and all participants in SAVE had histories of ischemic heart disease or acute myocardial infarction (SAVE). In both SOLVD and SAVE the risk of experiencing a major ischemic event such as myocardial infarction was reduced significantly following prolonged ACE inhibitor therapy. In the SOLVD trial, this effect was evident across a range of patient subgroups, including varying concomitant drug therapies. In both studies, several months elapsed before this benefit became apparent, suggesting an effect on underlying ischemic pathophysiology. A third trial of ACE inhibitor therapy postinfarction, the Acute Infarction Ramipril Efficacy (AIRE) Study, demonstrated a 27% reduction in all cause mortality but no effect on myocardial infarction after a 15-month mean follow-up. No effect of ACE inhibition on risk of survival or reinfarction was reported in the Cooperative New Scandinavian Enalapril Survival Study (CONSENSUS-II), which began the drug within 24 hours of infarction and terminated follow-up at 6 months, a time not likely to demonstrate infarction reduction benefit based on the SOLVD and SAVE observations. Neither AIRE nor CONSENSUS-II had objectively determined left ventricular dysfunction as an entry criterion, as did SOLVD and SAVE, but AIRE mandated "clinical" congestive heart failure prior to randomization. More recently, preliminary results from the third Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-3), the Fourth International Study of Infarct Survival (ISIS-4), and the Chinese Captopril Trial suggested that angiotensin-converting enzyme (ACE) inhibitor mortality benefits post-myocardial infarction would be detected in these megatrials as early as 35 days after the event.(ABSTRACT TRUNCATED AT 400 WORDS)

Pharmacotherapy of congestive heart failure. Currently used and experimental drugs

A survey is given of the currently used therapeutics in the treatment of chronic congestive heart failure. Symptomatic treatment is usually performed along the following lines: rest, sodium and fluid restriction to unload the decompensating heart, loop diuretics, angiotensin-converting enzyme inhibitors or other vasodilators; inotropic agents to improve the heart's mechanical performance; attempts to counteract the neuro-endocrine compensatory mechanisms, that is the activated sympathetic nervous and renin-angiotensin-aldosterone systems, as well as the rise in vasopressine levels. New insights have been obtained in the effects of cardiac glycosides, which are probably rather based on counteracting the elevated sympathetic neuronal activity than on their weak and uncertain inotropic action. Angiotensin-converting enzyme inhibitors are probably more effective than classical vasodilators owing to their additional interaction with the neuro-endocrine compensatory mechanisms. Ibopamine, a prodrug of epinine, appears to be rather a vasodilator and antagonist of the neuro-endocrine compensatory mechanisms than an inotropic agent. The most important clinical trials addressing the efficacy and adverse reactions to the various aforementioned therapeutics are discussed. New, experimental approaches in the drug treatment of chronic congestive heart failure include beta-blockers, calcium antagonists, vasopressin antagonists and inhibitors of atrial natriuretic peptide degradation.

Does heart transplantation confer additional benefit over medical therapy to patients who have waited > 6 months for heart transplantation?

OBJECTIVES

This study compared the survival of patients with heart failure who have waited > 6 months for heart transplantation with that patients who undergo heart transplantation after a similarly prolonged waiting period.

BACKGROUND

There are little data describing outcome in patients with severe heart failure who have waited for extended periods of time on the heart transplant waiting list.

METHODS

Sixty-three consecutive patients who spent > 6 months on the heart transplant waiting list were examined. Mean (+/- SD) age was 53 +/- 9 years, mean left ventricular ejection fraction was 19 +/- 6%, and all were taking digoxin and diuretic and vasodilator agents. Patients who underwent transplantation during the follow-up period were censored from the pretransplantation analysis, and their survival was examined as part of the posttransplantation phase of the study.

RESULTS

Of the 63 original patients examined, 25 underwent transplantation, 10 during inotropic or mechanical circulatory support. The pretransplantation mortality rate was 6% at 6 months after the 6-month milestone on the waiting list, 12% at 12 months and 22% at 18 months. The posttransplantation mortality rate was 5% at 6 months, 10% at 12 months and 24% at 18 months. There were no differences in survival at any time between the two phases of the study.

CONCLUSIONS

Survival of patients who have survived > 6 months on the heart transplant waiting list is generally good. Although heart transplantation did not appear to confer additional survival advantage over medical therapy, a large proportion of the patients who underwent transplantation were critically ill at the time of transplantation and would undoubtedly have died of progressive heart failure had they not undergone transplantation. We conclude that heart transplantation should still be considered a therapeutic alternative in patients with heart failure even after a prolonged waiting period on the heart transplant waiting list.

Survival after myocardial infarction in the rat. Role of tissue angiotensin-converting enzyme inhibition

BACKGROUND

Chronic treatment with high doses of angiotensin-converting enzyme (ACE) inhibitors prolongs survival after myocardial infarction. Since the plasma renin-angiotensin system (RAS) is not consistently activated in the chronic phase after myocardial infarction, the beneficial effects of ACE inhibition have been attributed, in part, to inhibition of an activated tissue RAS. However, a relation between tissue ACE inhibition and long-term efficacy (ie, concerning left ventricular [LV] hypertrophy and survival) has not been established. The present study was designed to evaluate the impact of low-dose ACE inhibition (predominant inhibition of plasma ACE) and high-dose ACE inhibition associated with substantial tissue ACE inhibition) on reversal of LV hypertrophy and 1-year mortality after myocardial infarction in the rat.

METHODS AND RESULTS

Infarcted rats were randomized to placebo, low-dose lisinopril, or high-dose lisinopril (each, n = 80) and compared with sham-operated animals (n = 40). In a separate group of animals, tissue ACE activity was determined after 6 weeks of therapy, demonstrating that both regimens were effective with regard to both plasma and pulmonary ACE inhibition; however, only high-dose lisinopril inhibited renal ACE. Neither dose affected LV ACE activity and ACE mRNA levels as determined by competitive polymerase chain reaction, whereas LV ANF mRNA levels were significantly reduced by high-dose lisinopril. High-dose lisinopril reduced arterial blood pressure and normalized right ventricular and LV weight and resulted in a substantial reduction of 1-year mortality, whereas the low dose did not (1 year mortality: placebo, 56.3%; low dose, 53.3%; high dose, 22.9%, P < .0001 versus low dose and versus placebo).

CONCLUSIONS

Hemodynamically effective ACE inhibition is required for reduction of LV hypertrophy and long-term mortality after myocardial infarction in the rat. Sustained inhibition of renal ACE during long-term therapy may contribute to the beneficial effect of high-dose lisinopril. Low-dose lisinopril, although exerting sustained inhibition of the plasma ACE, does not improve survival after myocardial infarction.

Effect of captopril on functional mitral regurgitation in dilated heart failure: a randomised double blind placebo controlled trial

OBJECTIVE

To determine the efficacy and dose requirements of captopril to reduce functional mitral regurgitation in patients with dilated heart failure.

DESIGN

A randomised double blind placebo controlled parallel arm trial. Incremental daily doses of 25 mg, 50 mg and 100 mg captopril used for a four week period each for a total of 12 weeks preceded by a two week placebo washout. Twenty eight ambulatory patients (mean age 72) New York Heart Association (NYHA) class II or III with apparently controlled ischaemic dilated heart failure (ejection fraction 29% (0.04%)) on digoxin, diuretics, and nitrates were randomised. All had at least grade 2/4 functional mitral regurgitation (> 5 cm2 regurgitant area on colour flow Doppler).

RESULTS

Twenty three patients completed the study (13 on placebo and 10 on captopril). Significant improvements were confined to the captopril group. Compared with placebo the following improvements were noted in the captopril treated group: mitral regurgitant area decreased from a threshold at 50 mg/day (p < 0.05, mean (95% confidence interval (95% CI)) 3.1 (0.2 to 6.0) cm2), with a further decrease at 100 mg/day (p < 0.01, mean (95% CI) 5.3 (3.1 to 7.5) cm2). Significant improvements in all the other measurements were noted only after 100 mg/day. Stroke volume increased (p < 0.01, mean (95% CI) 11, (1.4 to 21) ml), systemic vascular resistance decreased (p < 0.05, mean (95% CI) 414 (35 to 793) dyn s cm5), left atrial area decreased (p < 0.05, mean (95% CI) 4.3 (0.03 to 8.6) cm2), and deceleration time increased (p < 0.01, mean (95% CI) 52 ms (7 to 98) ms). Left ventricular diameter decreased marginally (p = 0.06, mean (95% CI) 4 (-0.05 to 9 mm). Duke activity index score increased (p < 0.001, median (95% CI) 6.8 (4.5 to 12) points). Heart rate, mean arterial blood pressure, serum creatinine, and serum potassium did not change with either placebo or captopril. No patient was withdrawn directly due to the side effects of captopril. In an open phase nine placebo patients given captopril in rapid increments reaching 100 mg/day in the fourth week showed similar improvements.

CONCLUSION

Captopril is efficacious in reducing functional mitral regurgitation in dilated heart failure. Patients require and must tolerate high doses (50-100 mg/day) for additive effects over supervised conventional treatment to occur.

Detection of left ventricular dysfunction after acute myocardial infarction: comparison of clinical, echocardiographic, and neurohormonal methods

OBJECTIVE

The SAVE study showed that captopril improves mortality in patients with left ventricular dysfunction after myocardial infarction and that this benefit occurred even in patients with no clinically overt heart failure. On the basis of this, it seems important to identify correctly which patients have left ventricular dysfunction after a myocardial infarction. The objective was to compare various methods of identifying patients with left ventricular dysfunction (left ventricular ejection fraction, LVEF, < or = 40%) after acute myocardial infarction. The methods compared were echocardiography (quantitative and qualitative visual assessment), clinical evaluation (subjective assessment and three clinical score methods), and measurement of plasma concentrations of cardiac natriuretic peptide hormones (atrial and brain natriuretic peptides, ANP and BNP).

DESIGN

Cross sectional study of left ventricular function in patients two to eight days after acute myocardial infarction.

SETTING

Coronary care unit of a teaching hospital.

PATIENTS

75 survivors of a recent myocardial infarction aged 40 to 88 with no history of cardiac failure and without cardiogenic shock at the time of entry to the study.

MAIN OUTCOME MEASURES

Sensitivities and specificities of the various methods of detecting left ventricular dysfunction were calculated by comparing them with a cross sectional echocardiographic algorithm for LVEF.

RESULTS

Clinical impression was poor at identifying LVEF < 40% (sensitivity 46%). Clinical scoring improved this figure somewhat (modified Peel index sensitivity 64%). Qualitative visual assessment echocardiography was a more sensitive method (sensitivity 82%) for detecting LVEF < 40%. Plasma BNP concentration was also a sensitive measure for detecting left ventricular dysfunction (sensitivity 84%) but plasma ANP concentration was much poorer (sensitivity 64%).

CONCLUSION

Left ventricular dysfunction is easily and reliably detected by echocardiographic measurement of LVEF and also by a quick qualitative echocardiographic assessment but is likely to be missed by clinical assessment alone. High concentrations of plasma BNP maybe another useful indicator of left ventricular dysfunction, particularly in hospitals where not all patients can be screened by echocardiography or radionuclide ventriculography after myocardial infarction.

Changes in passive mechanical stiffness of myocardial tissue with aneurysm formation

BACKGROUND

Myocardium undergoes complex cellular and histochemical alterations after acute myocardial infarction. These structural changes directly affect the mechanical stiffness of infarcted and remote myocardia. Previous investigations of infarct stiffness have been limited to uniaxial testing, which does not provide a unique description of the tissue's three-dimensional material properties. This study describes the first serial measurements of biaxial mechanical properties of sheep myocardium after anteroapical infarction.

METHODS AND RESULTS

Anteroapical infarctions of 23.7 +/- 2.5% of the left ventricular mass were produced by coronary arterial ligation in sheep. Biaxial force-extension measurements were made on freshly excised squares (6.45 cm2) of remote, noninfarcted, and infarcted myocardia before and 4 hours, 1 week, 2 weeks, and 6 weeks after ligation. Adjacent myocardial samples were assayed for hydroxyproline content. Force-extension data and a derived constitutive equation were used to describe stresses and strains and material properties of each sample. In sheep, anteroapical infarctions evolve into thin left ventricular aneurysms that consist of predominantly fibrous tissue with disrupted groups of muscle cells encased in scar. In the infarct, Cauchy stresses at 15% extensions (control stresses: circumferential, sigma C, 19.4 +/- 3.3 g/cm2; longitudinal, sigma L, 54.8 +/- 34.8 g/cm2) increase within 4 hours, peak at 1 to 2 weeks (sigma C, 338.5 +/- 143.6 g/cm2; sigma L, 310.7 +/- 45.9 g/cm2), and then decrease 6 weeks after infarction (sigma C, 115 +/- 47.2 g/cm2; sigma L, 53.2 +/-28.9 g/cm2). Stresses in the remote myocardium follow a similar time course but to a lesser extent than the infarcted region. Hydroxyproline content, a measure of collagen content, does not correlate with infarct stiffness but progressively increases to 69.7 +/- 7.6 micrograms/mg after 6 weeks. Stress-extension curves demonstrate directional anisotropy of both infarcted and remote myocardia.

CONCLUSIONS

The findings indicate that infarcted myocardium becomes more stiff during the first 1 to 2 weeks after anteroapical infarction and then more compliant. The infarct also exhibits directional anisotropy. These observations underscore the importance of ventricular material properties during the remodeling process after acute myocardial infarction and may partially explain the progressive left ventricular dilatation and functional deterioration that occur in some patients after anteroapical infarction.

Angiotensin-converting enzyme inhibitors in heart failure: new strategies justified by recent clinical trials

New information suggests that heart failure treatment strategies should change. Indeed, angiotensin-converting enzyme (ACE) inhibitors now should be considered first-line therapy in some instances. It is important, therefore, to review results of recently completed mortality end-point trials of ACE inhibitors in patients with congestive heart failure and asymptomatic left ventricular dysfunction. In the Treatment Trial of Studies of Left Ventricular Dysfunction (SOLVD), addition of enalapril to baseline therapy significantly improved prognosis in patients with mild to moderate heart failure. These results extend the findings of the Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS), and indicate that ACE inhibition is beneficial to patients with all grades of overt congestive heart failure. In the Prevention Trial of SOLVD, and the Survival and Ventricular Enlargement Study (SAVE), therapy with enalapril or captopril improved prognosis among patients with, generally, asymptomatic left ventricular dysfunction. In particular, the risk of development of overt heart failure was reduced. Importantly, a marked anti-ischaemic effect of ACE inhibition was identified in both the SOLVD and SAVE trials. Clinical data amassed in nearly 9000 patients identify a substantial role for ACE inhibition in patients with all grades of symptomatic heart failure as well as in those with asymptomatic left ventricular dysfunction (such as often follows a myocardial infarction). Data support early intervention with ACE inhibitor therapy alone in asymptomatic cardiac failure and triple combination therapy (ACE inhibitor, diuretic, digoxin) in patients with symptomatic congestive heart failure.

Hypertension and left ventricular hypertrophy: is drug therapy beneficial?

Left ventricular hypertrophy (LVH) is a consequence of long-standing hypertension and is considered to be an independent risk factor for cardiovascular morbidity and mortality. Several antihypertensive agents are capable of inducing regression of LVH, but it is not known which class of drugs is most effective. The impact of drug-induced reversal of hypertrophy on ventricular function remains a controversial issue. Furthermore, the long-term clinical benefits of LVH regression have yet to be documented. Controversies also exist regarding the clinical outcomes associated with drug-induced LVH regression.

Vascular renin-angiotensin-system, endothelial function and atherosclerosis?

Clinical observations demonstrate an enhanced risk for myocardial infarction in patients with sustained activation of the local and/or systemic renin-angiotensin system, such as a high renin-sodium profile or a heritably enhanced expression of angiotensin converting enzyme. Chronic renin-angiotensin system blockade by angiotensin converting enzyme inhibition in patients with moderate heart failure reduces the rate of myocardial infarction and reinfarction. Preliminary experimental evidence suggests that these clinical observations may be partially explained by a proatherogenic effect of an activated renin-angiotensin system, which can downregulate the endothelial releasability of nitric oxide. Nitric oxide exerts many potentially antiatherogenic effects on endothelium, platelets and low density lipoproteins and indirectly on monocytes and leukocytes. Hypertension-induced chronic distension of elastic arteries upregulates the local renin-angiotensin system in these arteries and thereby downregulates nitric oxide releasability. Enhanced local synthesis of the trophic factor angiotensin-II and reduced releasability of the antitrophic factor nitric oxide appear to cooperate in the trophic adaptation of the distended vessel wall to the enhanced load, but with the disadvantage of enhanced susceptibility for atheroma development due to reduced releasability of nitric oxide. Chronic blockade of the renin angiotensin system by angiotensin converting enzyme inhibitors or by angiotensin receptor type-1 antagonists normalizes a reduced endothelial releasability of nitric oxide in several models, partially by a bradykinin-dependent mechanism. This endothelial protection proved to attenuate the progression of atherosclerosis in experimental models. The antiatherogenic potential of renin angiotensin system blockade in humans is presently under study.

Controversies in the diagnosis and treatment of hypertension: a personal review of JNC V

In January 1993 the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure published its fifth report (JNC V). The report highlighted the importance of systolic hypertension and recommended that hypertension should be diagnosed--regardless of age--when systolic blood pressure readings are consistently > or = 140 mm Hg. JNC V reflected the opinion in JNC IV that several drug classes--including diuretics, beta blockers, angiotensin-converting enzyme (ACE) inhibitors, calcium antagonists, and alpha blockers--are suitable for initiating antihypertensive therapy. However, JNC V gave preference to diuretics and beta blockers because these drug classes have been shown to reduce the incidence of stroke and cardiovascular events in clinical trials; similar studies with the newer drug classes have not yet been completed. This recommendation is highly controversial because the benefits of diuretic and beta-blocker use are most evident in the elderly, and the beneficial effects of these drugs on the incidence of coronary events are relatively modest. Further, growing experience with ACE inhibitors and calcium antagonists shows that these agents lack the metabolic disadvantages of older agents and can exhibit antiatherosclerotic and antihypertrophic vasoactivity. Although to date the clinical benefits of the newer agents have been documented in conditions other than hypertension, the data are persuasive and indicate a probability that these drugs will improve prognosis in hypertensive patients. JNC V also emphasized lifestyle modifications; however, even when they decrease blood pressure, dietary and other nonpharmacologic strategies have not been shown to lower the incidence of clinical events.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-converting enzyme inhibitors in cardiovascular anesthesia

Besides the long-term regulation of extracellular fluid volume, the RAS plays an important physiologic role in maintaining venous return and blood pressure during acute hemodynamic stresses. ACE inhibitors may therefore alter venous return and cardiac output regulation during anesthesia and surgery. This may be regarded as a drawback of ACE inhibition when other factors interfere with cardiovascular homeostasis; deleterious hemodynamic events may therefore occur when blood volume is decreased, which may be frequent during cardiovascular anesthesia and surgery. However, the alternative solution should not be to stop ACE inhibitors preoperatively. This would allow recovery of RAS control of blood pressure, but at the expense of some regional circulations. From this point of view, preliminary results from early studies during cardiovascular anesthesia and surgery showing redistribution of regional blood flow with inhibition of ACE are encouraging; whether postoperative outcome can be improved deserves further studies. At this time, the evidence is that ACE inhibition does not allow the anesthesiologist to be tolerant of hypovolemia.