Streptococcal mural endocarditis and myocardial abscess occurring in a left ventricular aneurysm--case report and review

Infection of the mural endocardium within a left ventricular aneurysm without valvular involvement is exceedingly rare. The presenting clinical features can be non-specific, and a high index of suspicion is required for its diagnosis. Delay in diagnosis invariably leads to a fatal outcome. Although no controlled studies are available to guide therapy and management of these patients, appropriate antibiotic therapy and early surgical resection of the infected ventricular aneurysm remain the cornerstone of therapy.

Acidosis and contractility of heart muscle

The contractility of heart muscle is sensitive to small and physiological changes of extracellular pH. The reduction of contractility associated with an acidosis is determined by the fall of pH in the intracellular fluid. The function of many organelles within the cardiac cell is affected by hydrogen ions. The tension generated by isolated myofibrils at a fixed calcium concentration is reduced at low pH. The dominant mechanism for the reduction of contractility in whole tissue is competitive inhibition of the slow calcium current by hydrogen ions. The reduction of the slow calcium current is similar when the same fall of developed tension is induced by acidosis or by a reduction of extracellular calcium concentration. Measurement of tissue pH with fast-responding extracellular electrodes show that, in myocardial ischaemia, tissue acidosis develops at the same time or only seconds before the onset of contractile failure. Much of the reduced contractility can be accounted for by the severity of the acidosis. Although a mild acidosis can delay or prevent damage to the myocardium from ischaemia or hypoxia, a severe acidosis is not beneficial and may even cause tissue necrosis.

Can heart rate variation rule out sleep-disordered breathing in heart failure?

In patients with obstructive sleep apnoea (OSA), the very low frequency power spectral density index (VLFI) derived from analysis of heart rate correlates with the severity of obstructive apnoeas. VLFI is also associated with Cheyne-Stokes respiration/central sleep apnoea (CSR/CSA) in congestive heart failure (CHF). The present authors have tested the hypothesis that per cent VLFI, derived from a standard Holter ECG recording, can be used to detect the presence of OSA and CSR/CSA in patients with mild-to-moderate CHF. In total, 60 CHF patients underwent polysomnography with monitoring of heart rate. Data from 33 patients were analysed for per cent VLFI. Of the 60 patients, 27 were excluded due to atrial fibrillation, extensive pacing or frequent ventricular extra systoles. Receiver operator characteristic curves were constructed to establish the per cent VLFI that would optimally identify the presence or absence of sleep-disordered breathing. Using an apnoea-hypopnoea index>20 events.h-1 and setting the per cent VLFI at 2.23% yielded a sensitivity of 85%, specificity of 65%, positive predictive value of 61% and a negative predictive value of 87%. The latter increased to 100% when using an apnoea-hypopnoea cut-off of 30 events.h-1. In conclusion, these results suggest that spectral analysis of heart rate may be useful as a "rule-out test" for sleep-disordered breathing in patients with mild-to-moderate congestive heart failure.

ESC-CHF: guidelines for the aspirational and the practical

The recently published guidelines by the European Society of Cardiology on the diagnosis and treatment of chronic heart failure are well worth reading, include important new recommendations and are reviewed here.

Interventional versus conservative treatment in acute non-ST elevation coronary syndrome: time course of patient management and disease events over one year in the RITA 3 trial

OBJECTIVE

To determine whether, in acute non-ST elevation coronary syndrome, the benefit from early invasive coronary intervention compared with a conservative strategy of later symptom-guided intervention varies over time.

METHODS

In RITA 3 (Randomised Intervention Trial of unstable Angina 3) patients were randomly assigned to coronary angiography (median 2 days after randomisation) and appropriate intervention (n = 895) or to a symptom-guided conservative strategy (n = 915).

RESULTS

In the first week patients in both groups were at highest risk of death, myocardial infarction (MI) or refractory angina (incidence rate 40 times higher than in months 5-12 of follow up). There were 22 MIs and 6 deaths in the intervention group (largely due to procedure-related events, 14 MIs and 3 deaths) versus 17 MIs and 3 deaths in the conservative group. In the rest of the year there were an additional 12 versus 27 MIs, respectively (treatment-time interaction p = 0.021). Over one year in the intervention group there was a 43% reduction in refractory angina; 22% of patients underwent coronary artery bypass surgery and 35% underwent percutaneous coronary intervention only, which reduced refractory angina but provoked some early MIs; and 43% were still treated medically, mostly because of a favourable initial angiogram.

CONCLUSION

Any intervention policy needs to recognise the high risk of events in the first week and the substantial minority of patients not needing intervention. Intervention may be best targeted at higher risk patients, as the early hazards of the procedure are then offset by reduced subsequent events.

Diuretics for heart failure

BACKGROUND

Chronic heart failure is a major cause of morbidity and mortality world-wide. Diuretics are regarded as the first-line treatment for patients with congestive heart failure since they provide symptomatic relief. The effects of diuretics on disease progression and survival remain unclear.

OBJECTIVES

To assess the harms and benefits of diuretics for chronic heart failure

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Issue 2 2004), MEDLINE 1966-2004, EMBASE 1980-2004 and HERDIN database. We hand searched pertinent journals and reference lists of papers were inspected. We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

Only double-blinded randomised controlled trials of diuretic therapy comparing one diuretic with placebo, or one diuretic with another active agent (e.g. ACE inhibitors, digoxin) in patients with chronic heart failure were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted the data and assessed the eligibility and methodological quality of each trial. Extracted data were entered into the Review Manager 4.2 computer software, and analysed by determining the odds ratio for dichotomous data, and difference in means for continuous data, of the treated group compared with controls. The likelihood of heterogeneity of the study population was assessed by the Chi-square test. If there was no evidence of statistical heterogeneity and pooling of results was clinically appropriate, a combined estimate was obtained using the fixed-effects model.

MAIN RESULTS

We included 14 trials (525 participants), 7 were placebo-controlled, and 7 compared diuretics against other agents such as ACE inhibitors or digoxin. We analysed the data for mortality and for worsening heart failure. Mortality data were available in 3 of the placebo-controlled trials (202 participants). Mortality was lower for participants treated with diuretics than for placebo, odds ratio (OR) for death 0.24, 95% confidence interval (CI) 0.07 to 0.83; P = 0.02. Admission for worsening heart failure was reduced in those taking diuretics in two trials (169 participants), OR 0.07 (95% CI 0.01 to 0.52; P = 0.01). In four trials comparing diuretics to active control (91 participants), diuretics improved exercise capacity in participants with CHF, difference in means WMD 0.72 , 95% CI 0.40 to 1.04; P < 0.0001.

AUTHORS' CONCLUSIONS

The available data from several small trials show that in patients with chronic heart failure, conventional diuretics appear to reduce the risk of death and worsening heart failure compared to placebo. Compared to active control, diuretics appear to improve exercise capacity.

Echocardiographic features and brain natriuretic peptides in patients presenting with heart failure and preserved systolic function

OBJECTIVE

To characterise patients who appear to fulfil the diagnosis of heart failure with preserved systolic function clinically, echocardiographically, and by concentrations of brain-type natriuretic peptide (BNP).

METHODS

102 new cases of heart failure were identified over 24 months in 213 patients referred to a rapid access heart failure clinic. Patients with heart failure and preserved systolic function with contemporary markers of diastolic function were assessed to evaluate their cardiac status further.

RESULTS

Forty patients (39%) had an ejection fraction (EF) < 45% and 62 (61%) had an EF > or = 45%. Of these 62 patients, 30 (48%) fulfilled the case definition of diastolic heart failure. The remaining 32 (52%) had neither an EF < 45% nor abnormalities of diastolic function. Dobutamine stress echocardiography was performed on 26 (42%) patients with EF > or = 45%, which provided an alternative explanation for symptoms in 15 (58%) patients. Concentrations of BNP were higher in patients with diastolic abnormalities (mean (SEM) 101.4 (32.5) pg/ml v 58.4 (6.78) pg/ml, p = 0.042) and with no diastolic abnormalities (199 (37.9) pg/ml v 58.4 (6.78) pg/ml, p < 0.0001) than in patients with no heart failure.

CONCLUSION

Among ambulatory patients presenting with suspected heart failure in the community 19% have systolic dysfunction, 14% have diastolic dysfunction, and 15% seemingly have heart failure with neither systolic nor diastolic dysfunction. A new understanding, including alternative parameters of diastolic function, seems to be necessary to classify patients with heart failure and preserved systolic function.

Treatment of angina pectoris: associations with symptom severity

OBJECTIVE

To evaluate whether the frequency of anginal attacks in medically treated patients with stable angina is related to the intensity of anti-anginal treatment, the clinical history and coronary anatomy.

METHODS

Analysis of baseline data from the A Coronary disease Trial Investigating Outcome with Nifedipine GITS (ACTION) study, an ongoing placebo-controlled trial in 7669 patients with stable angina pectoris who require anti-anginal treatment.

RESULTS

Prior to randomisation, 8% of 7669 patients had no anginal attacks, 63% had occasional, 22% had regular, 4% had frequent and 3% had daily attacks. Men (79% of all patients) and patients with a history of MI (51%) had less frequent anginal attacks (P<0.0001). The number of coronary angiograms ever performed (70% had at least one angiogram), the extent of angiographic coronary disease (32% of those who had angiography had more than two-vessel disease), a history of peripheral artery disease (12%), the number of anti-anginal drugs used (64% were prescribed two or more such medications) and a history of revascularisation (a history of coronary bypass surgery was present in 23% and of balloon dilatation in 26%) were each positively associated with anginal attack frequency.

CONCLUSIONS

For the majority of patients with chronic stable angina not on a calcium-antagonist, medical treatment with other anti-anginal drugs is sufficient to control symptoms and only a minority of patients are refractory to medical treatment. Invasive treatments for chronic stable angina are only needed in a small proportion where symptoms persist.

Do men benefit more than women from an interventional strategy in patients with unstable angina or non-ST-elevation myocardial infarction? The impact of gender in the RITA 3 trial

AIMS

The RITA 3 trial randomized patients with non-ST-elevation myocardial infarction or unstable angina to strategies of early intervention (angiography followed by revascularization) or conservative care (ischaemia or symptom driven angiography). The aim of this analysis was to investigate the impact of gender on the effect of these two strategies.

METHODS AND RESULTS

In total, 1810 patients (682 women and 1128 men) were randomized. The risk factor profile of women at presentation was markedly different to men. There was evidence that men benefited more from an early intervention strategy for death or non-fatal myocardial infarction at 1 year (adjusted odds ratios 0.63, 95% confidence interval 0.41-0.98 for men and 1.79, 95% confidence interval 0.95-3.35 for women; interaction p-value=0.007). Men who underwent the assigned angiogram were more likely to be put forward for coronary artery bypass surgery, even after allowing for differences in disease severity.

CONCLUSION

An early intervention strategy resulted in a beneficial effect in men which was not seen in women although caution is needed in interpretation. Further research is needed to evaluate why women do not appear to benefit from early intervention and to identify treatments that improve the prognosis of women.

Beta-adrenoceptor subtype dependence of chronotropy in mouse embryonic stem cell-derived cardiomyocytes

Cardiomyocytes derived from embryonic stem cells (ESCM) have potential both as an experimental model for investigating cardiac physiology and as a source for tissue repair. For both reasons it is important to characterise the responses of these cells, and one of the key modulators of contraction is the beta-adrenergic system. We therefore undertook a detailed study of the response of the spontaneous beating rate of ESCM to beta-adrenoceptor (betaAR) stimulation. Embryoid bodies (EBs) were generated from murine ES line E14Tg2a by the hanging drop method, followed by plating. Spontaneously beating areas were seen starting from 9-14 days after differentiation: the experiments described here were performed on EBs between developmental day 19 and 48. Beating cell layers were seeded with charcoal to allow tracking of movement by a video-edge detection system. Experiments were performed in physiological medium containing 1 mM Ca2+ at 37 degrees C. Isoprenaline (Iso) increased beating rate with an EC50 value of 52 nM. Iso (0.3 microM) increased basal rate from 67 +/- 7 beats per minute (bpm) to 138 +/- 18 bpm, P < 0.001, n = 22. At earlier developmental time points the response to Iso was not maintained through 5 min exposure; this spontaneous desensitisation only being observed before day 36. A repeat application of Iso after a wash period of 20 min produced reproducible effects on beating rate. Subtype dependence of the betaAR response was determined by comparing an initial response with a second in the presence of selective beta1- or beta2AR antagonists. In the presence of the specific beta1AR-blocker CGP 20712A (300 nM) the increase in rate with Iso was reduced from 207 +/- 42% of basal to 128 +/- 13%, P < 0.01. With the beta2AR-blocker ICI 118,551 (50 nM) there was no significant change in Iso response. Exposure to the muscarinic agonist, carbachol (10 microM), inhibited the increase in frequency mediated by isoprenaline, but had mixed stimulatory and inhibitory effects on basal rate. This study extends the characterisation of ESCM as a preparation for studying receptor pharmacology, and indicates that the beta1AR is the predominant subtype mediating increases in contraction rate in murine ESCM.

The Warfarin/Aspirin Study in Heart failure (WASH): a randomized trial comparing antithrombotic strategies for patients with heart failure

BACKGROUND

Heart failure is commonly associated with vascular disease and a high rate of athero-thrombotic events, but the risks and benefits of antithrombotic therapy are unknown.

METHODS

The current study was an open-label, randomized, controlled trial comparing no antithrombotic therapy, aspirin (300 mg/day), and warfarin (target international normalized ratio 2.5) in patients with heart failure and left ventricular systolic dysfunction requiring diuretic therapy. The primary objective was to demonstrate the feasibility and inform the design of a larger outcome study. The primary clinical outcome was death, nonfatal myocardial infarction, or nonfatal stroke.

RESULTS

Two hundred seventy-nine patients were randomized and 627 patient-years exposure were accumulated over a mean follow-up time of 27 +/- 1 months. Twenty-six (26%), 29 (32%), and 23 (26%) patients randomized to no antithrombotic treatment, aspirin, and warfarin, respectively, reached the primary outcome (ns). There were trends to a worse outcome among those randomized to aspirin for a number of secondary outcomes. Significantly (P =.044) more patients randomized to aspirin were hospitalized for cardiovascular reasons, especially worsening heart failure.

CONCLUSIONS

The Warfarin/Aspirin Study in Heart failure (WASH) provides no evidence that aspirin is effective or safe in patients with heart failure. The benefits of warfarin for patients with heart failure in sinus rhythm have not been established. Antithrombotic therapy in patients with heart failure is not evidence based but commonly contributes to polypharmacy.

Heart failure in a district general hospital: are target doses of beta-blockers realistic?

BACKGROUND

Carvedilol therapy reduces mortality in patients with chronic heart failure. Multi-centre studies suggest a low first dose failure rate and high levels of tolerability to carvedilol. Little is known, however, concerning the eligibility and tolerance to treatment with carvedilol within a district general hospital setting.

AIM

To evaluate the eligibility and tolerance of patients with heart failure to carvedilol within a district general hospital.

DESIGN

Prospective clinical audit analysis.

METHODS

We assessed 100 heart failure patients eligibility to commence carvedilol therapy. In those who satisfied clinical criteria, we evaluated first dose failure rate, target dose achievement, reasons for intolerance, heart rate and blood pressure reduction and resource requirements over a six-month period.

RESULTS

Of 100 patients, 16% had contra-indications to commence carvedilol and 22% were receiving a beta-blocker as part of their existing heart failure therapy. Although 62% satisfied eligibility criteria, 1% refused therapy, thus 61% were initiated on carvedilol. The first dose failure rate was 11.5% and 6.6% of patients achieved 'target dose'. Mean heart rate and systolic blood pressure reductions were 15 (SE 1.2)bpm and 17 (SE 1.7) mmHg, respectively. Resource requirements included 155 hours of work-time for a trained heart failure specialist nurse and doctor.

CONCLUSIONS

In the general setting, eligible patients appear to display a high first dose failure rate, poor tolerance to higher doses and achievement of a 'target dose' of carvedilol. Responses to adrenergic blockade were similar to previously published data, irrespective of the final tolerated dose, suggesting that the concept of achieving a 'target dose' may not be clinically useful. Guidelines and treatment protocols for heart failure should reflect not only what is considered gold standard, but also what is practical in general hospitals.

The therapeutic potential of new insights into myocardial excitation-contraction coupling

The physiological mechanisms that link myocyte depolarisation and contraction are referred to collectively as excitation-contraction coupling. This important process uses calcium as a second messenger to convert electrical depolarisation of the myocyte sarcolemma into the coordinated contraction of the cell's internal myofilament apparatus. The inotropic properties of the cell are determined by the efficiency of this process and when this efficiency is lost contractile dysfunction and heart failure develop, along with a propensity for arrhythmias. Previous attempts to use positive inotropic drugs in the management of chronic heart failure have been disappointing. Such drugs have been associated with unacceptable side effects and worse morbidity and mortality outcomes, primarily through their non-specific amplification of intracellular cascade pathways that modify the cell's inotropic state. As a result of recent advances in our understanding of how excitation-contraction coupling works in both health and disease it may be possible to design more specifically targeted drug treatment that has the potential to avoid the detrimental effect of currently available drugs while at the same time improving the inotropic properties of the cell.

Mode of death in heart failure: findings from the ATLAS trial

OBJECTIVE

To investigate markers that predict modes of death in patients with chronic heart failure.

DESIGN

Randomised, double blind, three period, comparative, parallel group study (ATLAS, assessment of treatment with lisinopril and survival).

PATIENTS

3164 patients with mild, moderate, or severe chronic heart failure (New York Heart Association functional class II-IV).

INTERVENTIONS

High dose (32.5 or 35 mg) or low dose (2.5 or 5 mg) lisinopril once daily for a median of 46 months.

MAIN OUTCOME MEASURES

All cause mortality, cardiovascular mortality, sudden death, and chronic heart failure death related to prognostic factors using competing risks analysis. Mode of death was classified by trialists and by an independent end point committee.

RESULTS

Age, male sex, pre-existing ischaemic heart disease, increasing heart rate, creatinine concentration, and certain drugs taken at randomisation were markers of increased risk of all cause mortality and cardiovascular death. There were risk markers for sudden death that were different from the risk markers for death from chronic heart failure. Low systolic blood pressure at baseline, raised creatinine, reduced serum sodium or haemoglobin, and increased heart rate were associated with chronic heart failure death. Use of beta blockers or antiarrhythmic agents (mainly amiodarone) was associated with a reduced risk of sudden death, whereas long acting nitrates and previous use of angiotensin converting enzyme inhibitors were markers for increased risk.

CONCLUSIONS

The use of competing risks analysis on the data from the ATLAS study has identified variables associated with certain modes of death in heart failure patients. This approach to analysing outcomes may make it possible to predict which patients might benefit most from particular therapeutic interventions.

Interventional versus conservative treatment for patients with unstable angina or non-ST-elevation myocardial infarction: the British Heart Foundation RITA 3 randomised trial. Randomized Intervention Trial of unstable Angina

BACKGROUND

Current guidelines suggest that, for patients at moderate risk of death from unstable coronary-artery disease, either an interventional strategy (angiography followed by revascularisation) or a conservative strategy (ischaemia-driven or symptom-driven angiography) is appropriate. We aimed to test the hypothesis that an interventional strategy is better than a conservative strategy in such patients.

METHODS

We did a randomised multicentre trial of 1810 patients with non-ST-elevation acute coronary syndromes (mean age 62 years, 38% women). Patients were assigned an early intervention or conservative strategy. The antithrombin agent in both groups was enoxaparin. The co-primary endpoints were a combined rate of death, non-fatal myocardial infarction, or refractory angina at 4 months; and a combined rate of death or non-fatal myocardial infarction at 1 year. Analysis was by intention to treat.

FINDINGS

At 4 months, 86 (9.6%) of 895 patients in the intervention group had died or had a myocardial infarction or refractory angina, compared with 133 (14.5%) of 915 patients in the conservative group (risk ratio 0.66, 95% CI 0.51-0.85, p=0.001). This difference was mainly due to a halving of refractory angina in the intervention group. Death or myocardial infarction was similar in both treatment groups at 1 year (68 [7.6%] vs 76 [8.3%], respectively; risk ratio 0.91, 95% CI 0.67-1.25, p=0.58). Symptoms of angina were improved and use of antianginal medications significantly reduced with the interventional strategy (p<0.0001).

INTERPRETATION

In patients presenting with unstable coronary-artery disease, an interventional strategy is preferable to a conservative strategy, mainly because of the halving of refractory or severe angina, and with no increased risk of death or myocardial infarction.

NICE: guessing is not guidance. National Institute for Clinical Excellence

A preliminary assessment of the extent to which the National Institute for Clinical Excellence (NICE) has achieved its goals within cardiovascular medicine is presented. NICE is a government sponsored agency operating in the UK which attempts to assess the value of medical therapies, devices, and surgery for a wide range of medical and surgical problems. Its recommendations determine whether a particular therapy can be adopted in the National Health Service.

Hospitalization of patients with heart failure: a population-based study

AIMS

To describe the clinical course of heart failure in a population-based sample of incident cases, and to identify factors predicting hospitalization and mortality.

METHODS AND RESULTS

Three hundred and thirty-two incident cases were identified over 15 months; 208 inpatients and 124 outpatients. Thirty-eight inpatients died during the first hospital admission (case fatality 18%) leaving 294 at risk of subsequent hospitalization. Over an average follow-up of 19 months, 173 cases were hospitalized on 311 occasions. Two hundred and twenty-four (72%) of these admissions were unplanned, with 51% due to worsening heart failure. One hundred and ten cases died over the same period. Cases diagnosed as an inpatient had 26 more admissions for worsening heart failure per 100 cases during follow-up (95% CI 9 to 44) compared to cases diagnosed as an outpatient, and also a higher mortality (hazard ratio 3.1 (95% CI 1.9 to 5.1)). Age was the only factor associated with an increased risk of hospitalization for worsening heart failure, but age, functional class and serum creatinine were predictive of mortality.

CONCLUSIONS

New cases of heart failure are at high risk of subsequent hospitalization, especially during the first months after diagnosis. Whilst predicting which patients will be hospitalized is difficult, interventions designed to reduce hospitalizations for worsening heart failure should be targeted at elderly inpatients with a new diagnosis.

Measurement of left ventricular volume after anterior myocardial infarction: comparison of magnetic resonance imaging, echocardiography, and radionuclide ventriculography

We have compared echocardiography (echo) and radionuclide ventriculography (RNV) with magnetic resonance imaging (MRI) for the measurement of left ventricular (LV) volume and ejection fraction. Seventy asymptomatic patients were studied up to 12 days after first Q wave anterior myocardial infarction and again after 6 months. Each patient had LV volume measured by all three techniques within 24 hours of each other on each occasion. LV end-systolic and end-diastolic volume index (LVESVI and LVEDVI) and LV ejection fraction (LVEF) were measured using the modified Simpson formula (echo), a counts-based method (RNV), and a multislice area summation method (MRI). Radionuclide volumes were measured both with and without correction for attenuation of isotope. Echocardiography overestimated LV volume compared with MRI. Mean (SD) differences (echo-MRI) were: LVEDVI + 10.6 ml/m2 (16.8), LVESVI + 13.7 ml/m2 (12.9), LVEF -8.5% (11.2). RNV underestimated both volume and ejection fraction compared with MRI. Mean differences (RNV-MRI) were: LVEDVI -25.4 ml/m2 (23.8), LVESVI -5.0 ml/m2 (18.6), LVEF -13.8% (10.4). Variability in the difference between echo and MRI and between RNV and MRI was very similar for LVEF (coefficient of variation 23.9% echo, 22.2% RNV) but there was greater variability in the radionuclide than the echo measurements of absolute volume. Variability of the radionuclide measurements was reduced by not correcting for attenuation, and this finding may improve the radionuclide technique for serial measurements of percentage change in volume. Long-term inter-study reproducibility of MRI for LVEF (coefficient of reproducibility) was 10.9%, for echo it was 10.6%, and for RNV it was 14.6%. We conclude that measurements of LV volume depend on the method used and are not interchangeable. Echocardiography agrees more closely with MRI than RNV for the measurement of absolute volume, but the two techniques are similar for the measurement of LVEF.

Implications of recent heart failure trials for patients with hypertension

There are two major reasons why hypertension is an important risk factor for heart failure. The first is that an elevated blood pressure increases the wall stress in the left ventricle. The second is that hypertension, in a complex manner, contributes to the development of atheromatous vascular disease. Among the more common causes of heart failure are the sequelae of coronary heart disease. The treatment of hypertension modifies the progression to heart failure and the occurrence of coronary events. In patients who have heart failure, hypotension rather than hypertension is a predictor of a poor outcome, likely because low blood pressure is a consequence of damage to the myocardium. The clinical message is that hypertension should be treated aggressively. Where heart failure is a likely outcome, or where hypertension occurs in the presence of heart failure, there is a strong case for using drugs that have been shown to be beneficial in the treatment of both hypertension and heart failure.

Cardiovascular critical event pathways for the progression of heart failure; a report from the ATLAS study

AIMS

To determine the sequence of critical cardiovascular events in the progression of heart failure, and whether aetiology or high-dose vs low-dose lisinopril affected these pathways.

METHODS AND RESULTS

This was a post-hoc investigation of the ATLAS database, which comprised 3164 patients with chronic heart failure, randomized to low- (2.5-5.0 mg. day(-1)) or high-dose (32.5-35.0 mg. day(-1)) lisinopril, followed up for a median of 46 months. Two-thirds (64.3%) of patients had heart failure attributed to ischaemic heart disease. During the study, most patients (61.1%) had at least one cardiovascular hospitalization and 42.5% of all patients died: most deaths (88.2%) were cardiovascular. Nearly half (49.7%) of the cardiovascular deaths were considered sudden and 45.2% of cardiovascular deaths occurred as the first cardiovascular event. A third (30.2%) of deaths resulted from heart failure and were generally preceded by hospitalization, either for heart failure (85.5%), myocardial ischaemic events (21.7%) or arrhythmias (18.0%). Compared with low-dose, high-dose lisinopril was associated with a lower risk of death or hospitalization for any reason (P=0.002) and death or hospitalization with worsening heart failure (P<0.001). High-dose lisinopril delayed the time to all-cause mortality and hospitalization for chronic heart failure by 7.1 months.

CONCLUSIONS

Vascular and arrhythmic events may not only be important precipitants of sudden death, but were also seen to contribute to the progression of heart failure. A reduction in vascular events, as well as benefits on ventricular remodelling, could account for the decrease in death or hospitalization with high-dose lisinopril.

The underreporting of results and possible mechanisms of 'negative' drug trials in patients with chronic heart failure

Large drug trials have become very important to determine which drugs should be used in the treatment of patients with chronic heart failure (CHF). When these trials showed "positive" results, publication of the data soon followed, leading to a substantial impact on prescription patterns. In the case of "negative" results, many times they were not published, or were reported as an abstract or as short paper disclosing only the main findings. In this article we will discuss some of these trials that were conducted in the last 10 years, since we believe they may provide insight into the pathophysiology and treatment options in CHF.

Acquired growth hormone resistance in patients with chronic heart failure: implications for therapy with growth hormone

OBJECTIVES

We aimed to determine whether growth hormone (GH) resistance is present in patients with chronic heart failure (CHF) and whether it may be linked to the biochemical response to GH treatment.

BACKGROUND

Acquired GH resistance is a feature of severe illness, in particular, cachexia. In patients with CHF, the response to GH therapy appears to be variable.

METHODS

Biochemical markers of the GH-insulin-like growth factor-I (IGF-I) axis were compared in 21 cachectic patients with CHF, 51 noncachectic patients and 26 healthy control subjects. In separate studies, the predictive value of baseline biochemical variables for the IGF-I response to GH treatment was analyzed.

RESULTS

Cachectic patients showed an increase of total GH and immunologically intact GH (p < or = 0.0002) and a decrease of GH-binding protein (BP) (p = 0.005), IGF-BP3 (p = 0.01) and IGF-I (p = 0.06), compared with noncachectic patients. Similar changes were found when the cachectic group was compared with the control group. No differences were found between noncachectic patients and control subjects. Levels of GH-BP correlated with the IGF-I/GH ratio in all subgroups (all p < or = 0.002). Baseline GH-BP levels were related to the increase of IGF-I levels in response to GH treatment in patients with CHF after 24 h (r = 0.83, p = 0.005; n = 9; study 2), 44 days (r = 0.52, p = 0.007; n = 25; study 3) and 96 days (r = 0.54, p = 0.006; n = 24; study 3).

CONCLUSIONS

Most cachectic and some noncachectic patients with CHF show features of acquired GH resistance. The principal predictors of the biochemical features of GH resistance and of the poor biochemical response to short-term and longer-term GH treatment are GH-BP plasma levels. The presence of GH resistance is potentially a major factor determining the response to GH therapy in patients with CHF.

Peripheral chemoreceptor hypersensitivity: an ominous sign in patients with chronic heart failure

BACKGROUND

Peripheral chemoreceptor hypersensitivity is a feature of abnormal cardiorespiratory reflex control in chronic heart failure (CHF) and may contribute to sympathetic overactivity, attenuated baroreflex sensitivity (BRS), and excessive ventilation during exercise. We studied whether augmented peripheral chemosensitivity carries independent prognostic significance.

METHODS AND RESULTS

We assessed peripheral chemosensitivity (ventilatory response to hypoxia using transient inhalation of pure nitrogen) and BRS (phenylephrine and spectral methods) in 80 consecutive CHF patients (age 58+/-9 years; left ventricular ejection fraction [LVEF] 24+/-12%; peak oxygen consumption [peak VO(2)] 18+/-7 mL(-1). min(-1)). CHF patients demonstrated augmented peripheral chemosensitivity and decreased BRS (all P<0.01 versus reference values). During follow-up (median 41 months, >3 years in all survivors), 37 patients died. High peripheral chemosensitivity (>0.72 L. min(-1). %SaO(2)(-1)) predicted impaired survival (hazard ratio 3.2, 95% CI 1.6 to 6.0, P=0.0006). In the 27 patients (34%) with high peripheral chemosensitivity, 3-year survival was 41% (95% CI 22% to 60%) compared with 77% (66% to 89%) in 53 patients with normal chemosensitivity (P=0.0002). In multivariate analyses, augmented chemosensitivity independently predicted death (hazard ratio 2.8, 95% CI 1.5 to 5.5, adjusted for age, peak VO(2), and VE/VCO(2) [P=0.002]; hazard ratio 2.6, 95% CI 1.3 to 5.1, adjusted for age, LVEF, and peak VO(2) [P=0.008]). Depressed BRS was related to unfavorable prognosis in univariate analysis (P=0.05) but not in multivariate analyses.

CONCLUSIONS

Hypersensitivity of the peripheral chemoreceptors independently predicts adverse prognosis in ambulatory patients with CHF. This hyperactive excitatory reflex, through its inhibitory effect on the baroreflex, may be the reason for the previously observed prognostic association of the latter.

Enhanced ventilatory response to exercise in patients with chronic heart failure and preserved exercise tolerance: marker of abnormal cardiorespiratory reflex control and predictor of poor prognosis

BACKGROUND

In patients with chronic heart failure (CHF) and preserved exercise tolerance, the value of cardiopulmonary exercise testing for risk stratification is not known. Elevated slope of ventilatory response to exercise (VE/VCO(2)) predicts poor prognosis in advanced CHF. Derangement of cardiopulmonary reflexes may trigger exercise hyperpnea. We assessed the relationship between cardiopulmonary reflexes and VE/VCO(2)and investigated the prognostic value of (VE/VCO(2)) in CHF patients with preserved exercise tolerance.

METHODS AND RESULTS

Among 344 consecutive CHF patients, we identified 123 with preserved exercise capacity, defined as a peak oxygen consumption (PEAK VO(2)) >/=18 mL. kg(-1). min(-1) (age 56 years; left ventricular ejection fraction 28%; peak VO(2) 23.5 mL. kg(-1). min(-1)). Hypoxic and hypercapnic chemosensitivity (n=38), heart rate variability (n=34), baroreflex sensitivity (n=20), and ergoreflex activity (n=20) were also assessed. We identified 40 patients (33%) with high VE/VCO(2) (ie, >34.0). During follow-up (49+/-22 months, >3 years in all survivors), 34 patients died (3-year survival 81%). High VE/VCO(2) (hazard ratio 4.3, P<0.0001) but not peak f1.gif" BORDER="0">O(2) (P=0.7) predicted mortality. In patients with high VE/VCO(2), 3-year survival was 57%, compared with 93% in patients with normal VE/VCO(2) P<0.0001). Patients with high VE/VCO(2) demonstrated impaired reflex control, as evidenced by augmented peripheral (P=0.01) and central (P=0.0006) chemosensitivity, depressed low-frequency component of heart rate variability (P<0.0001) and baroreflex sensitivity (P=0.03), and overactive ergoreceptors (P=0.003) compared with patients with normal VE/VCO(2).

CONCLUSIONS

In CHF patients with preserved exercise capacity, enhanced ventilatory response to exercise is a simple marker of a widespread derangement of cardiovascular reflex control; it predicts poor prognosis, which VO(2) does not.

Coronary artery disease as the cause of incident heart failure in the population

AIMS

New approaches in the treatment of ischaemic left ventricular dysfunction, including revascularization, make it increasingly important to identify heart failure cases resulting from coronary artery disease. Without angiography these cases may be missed. We investigated the frequency of coronary artery disease in incident cases of heart failure in the population.

METHODS AND RESULTS

We identified all incident cases of heart failure in a population of 292 000 in South London, U.K. by monitoring patients admitted to hospital and through a rapid access heart failure clinic. The presence and severity of coronary artery disease was identified by coronary angiography in patients under 75 years. Myocardial perfusion scanning was used to elucidate the aetiological significance of the coronary artery disease and identify hibernating myocardium. Three hundred and thirty-two cases of new heart failure were identified over 15 months. One hundred and thirty-six cases were under 75 years and angiography was undertaken in 99/136 (73%). Coronary artery disease was the aetiology in 71/136 (52%). In 18 of these 71 cases (25%), the aetiology was not recognised to be due to coronary artery disease prior to angiography, including eight cases with hibernating myocardium.

CONCLUSION

Coronary artery disease is the cause of 52% (95% CI 43-61%) of incident heart failure in the general population under 75 years. Clinical assessment without angiography under-estimates the proportion of patients with coronary artery disease, and fails to identify those patients who may benefit from revascularization.

Toleration of high doses of angiotensin-converting enzyme inhibitors in patients with chronic heart failure: results from the ATLAS trial. The Assessment of Treatment with Lisinopril and Survival

BACKGROUND

Treatment with angiotensin-converting enzyme (ACE) inhibitors reduces mortality and morbidity in patients with chronic heart failure (CHF), but most affected patients are not receiving these agents or are being treated with doses lower than those found to be efficacious in trials, primarily because of concerns about the safety and tolerability of these agents, especially at the recommended doses. The present study examines the safety and tolerability of high- compared with low-dose lisinopril in CHF.

METHODS

The Assessment of Lisinopril and Survival study was a multicenter, randomized, double-blind trial in which patients with or without previous ACE inhibitor treatment were stabilized receiving medium-dose lisinopril (12.5 or 15.0 mg once daily [OD]) for 2 to 4 weeks and then randomized to high- (35.0 or 32.5 mg OD) or low-dose (5.0 or 2.5 mg OD) groups. Patients with New York Heart Association classes II to IV CHF and left ventricular ejection fractions of no greater than 0.30 (n = 3164) were randomized and followed up for a median of 46 months. We examined the occurrence of adverse events and the need for discontinuation and dose reduction during treatment, with a focus on hypotension and renal dysfunction.

RESULTS

Of 405 patients not previously receiving an ACE inhibitor, doses in only 4.2% could not be titrated to the medium doses required for randomization because of symptoms possibly related to hypotension (2.0%) or because of renal dysfunction or hyperkalemia (2.3%). Doses in more than 90% of randomized patients in the high- and low-dose groups were titrated to their assigned target, and the mean doses of blinded medication in both groups remained similar throughout the study. Withdrawals occurred in 27.1% of the high- and 30.7% of the low-dose groups. Subgroups presumed to be at higher risk for ACE inhibitor intolerance (blood pressure, <120 mm Hg; creatinine, > or =132.6 micromol/L [> or =1.5 mg/dL]; age, > or =70 years; and patients with diabetes) generally tolerated the high-dose strategy.

CONCLUSIONS

These findings demonstrate that ACE inhibitor therapy in most patients with CHF can be successfully titrated to and maintained at high doses, and that more aggressive use of these agents is warranted.

A Rapid Access Heart Failure Clinic provides a prompt diagnosis and appropriate management of new heart failure presenting in the community

BACKGROUND AND AIMS

The diagnosis of heart failure is an important clinical problem and yet reported diagnostic accuracy in primary care is less than 50%. We established a Rapid Access Heart Failure Clinic (RAHFC) in a district general hospital serving a population of 292,000 in SE London, UK, to diagnose and manage new cases of heart failure presenting for the first time in the community.

METHODS

Patients with suspected new onset heart failure were referred by their Primary Care Physician without appointment for clinical assessment on the same or next working day. Assessment by a specialist registrar in cardiology included history, examination, chest X-ray, electrocardiogram (ECG) and echocardiogram. When a diagnosis of heart failure was made appropriate treatment, including angiotensin converting enzyme inhibitors (ACEI), was started.

RESULTS

Over 15 months 383 patients were seen (0.4 cases/100,000 population/weekday) 178/383 (46%) were considered to have definite or possible heart failure at the initial assessment in the RAHFC. A normal ECG (negative predictive value 94%) and chest X-ray virtually excluded the diagnosis of heart failure. After subsequent specialist investigations and follow-up, including a trial of therapy where appropriate, 101/383 (26%) were finally diagnosed as clinical heart failure. ACEI therapy was commenced in 56/57 (98%) of patients in whom it was considered appropriate.

CONCLUSION

The RAHFC provided rapid assessment, prompt diagnosis and early introduction of life prolonging therapy for patients presenting with suspected heart failure in the community.

Efficacy and safety of high-dose lisinopril in chronic heart failure patients at high cardiovascular risk, including those with diabetes mellitus. Results from the ATLAS trial

AIMS

An analysis was designed to determine whether chronic heart failure patients at high cardiovascular risk benefited to the same extent from high-dose lisinopril as the whole ATLAS population.

METHODS AND RESULTS

A retrospective analysis was performed on high-risk heart failure patients in the Assessment of Treatment with Lisinopril And Survival (ATLAS) trial (total number of patients 3164) comparing highdose (32.5-35 mg. day(-1)) vs low-dose (2.5-5 mg. day(-1)) lisinopril for a median of 46 months. These high-risk patients included those with hypotension, hyponatraemia, compromised renal function, the elderly and patients with diabetes mellitus at baseline. In the whole study population, high-dose lisinopril led to a trend in risk reduction of all-cause mortality (primary end-point P=0.128) and a significant risk reduction in all-cause mortality plus hospitalization (principal secondary end-point P=0.002). Subgroup analyses were performed for these end-points. There were no consistent interactions between age, baseline sodium, creatinine or potassium values, and treatment effect. Diabetics showed a beneficial response to high-dose therapy that was at least as good as that in non-diabetics. The underlying higher morbidity/mortality rates in diabetics mean that high-dose lisinopril has potential for a larger absolute clinical impact in these patients.

CONCLUSION

Long-term high-dose lisinopril was as effective and well-tolerated in high-risk patients, including those with diabetes mellitus, as for the ATLAS study population as a whole.

Low doses vs. high doses of the angiotensin converting-enzyme inhibitor lisinopril in chronic heart failure: a cost-effectiveness analysis based on the Assessment of Treatment with Lisinopril and Survival (ATLAS) study. The ATLAS Study Group

OBJECTIVE

A cost-effectiveness analysis of high and low doses of the angiotensin-converting enzyme (ACE) inhibitor lisinopril in the treatment of chronic heart failure.

METHODS

A cost-effectiveness analysis using data from a randomized controlled trial, ATLAS, where 3164 patients with chronic heart failure were allocated to a high-dose (daily target dose 32.5-35 mg) or low-dose strategy (daily target dose 2.5-5.0 mg) of lisinopril. Differential costs were based on resource use data collected in the trial costed using UK unit costs. Cost-effectiveness analysis related differential costs to differential life-years during a 4-year trial follow-up.

RESULTS

The mean total number of hospital in-patient days per patient was 18. 5 in the high dose group and 22.5 in the low dose group. Over the whole duration of the trial, the mean (S.D.) daily dose of lisinopril in the high-dose group was 22.5 mg (15.7 mg) compared to 3.2 mg (2.5 mg) in the low-dose group. The mean difference in cost per patient was pound sterling 397 lower in the high-dose group [95% CI (high-dose-low-dose) - pound sterling 1263 to pound sterling 436]. Mean life-years per patient were 0.085 years higher in the high-dose group [95% CI (high-dose-low-dose) -0.0074 to 0.1706). Based on mean costs and life-years, high-dose therapy dominates low-dose (less costly and more effective). Allowing for uncertainty in mean costs and life-years, the probability of high-dose therapy being less costly than low dose was 82%. If a decision maker is willing to pay at least pound sterling 3600 per life-year gained, the probability of high-dose being more cost-effective was 92%.

CONCLUSIONS

The ATLAS Study showed that the treatment of heart failure with high-doses of lisinopril has a high probability of being more cost-effective than low-dose therapy.

First permanent implant of the Jarvik 2000 Heart

BACKGROUND

Heart failure is a major public-health concern. Quality and duration of life on maximum medical therapy are poor. The availability of donor hearts is severely limited, therefore an alternative approach is necessary. We have explored the use of a new type of left-ventricular assist device intended as a long-term solution to end-stage heart failure.

METHODS

As part of a prospective clinical trial, we implanted the first permanent Jarvik 2000 Heart--an intraventricular device with an innovative power delivery system--into a 61-year-old man (New York Heart Association functional class IV) with dilated cardiomyopathy. We assessed the effect of this left-ventricular assist device on both native heart function and the symptoms and systemic characteristics of heart failure.

FINDINGS

The Jarvik 2000 Heart sustained the patient's circulation, and was practical and user-friendly. After 6 weeks, exercise tolerance, myocardial function, and end-organ function improved. Symptoms of heart failure have resolved, and continuous decreased pulse-pressure perfusion has had no adverse effects in the short term. There has been no significant haemolysis and no device-related complications. The skull-mounted pedestal is unobtrusive and has healed well.

CONCLUSIONS

The initial success of this procedure raises the possibility of a new treatment for end-stage heart failure. In the longer term, its role will be determined by mechanical reliability.

Acute coronary findings at autopsy in heart failure patients with sudden death: results from the assessment of treatment with lisinopril and survival (ATLAS) trial

BACKGROUND

Sudden unexpected death frequently occurs in chronic heart failure. The importance of acute coronary events in triggering sudden death (SD) is unclear.

METHODS AND RESULTS

We evaluated at autopsy the prevalence of acute coronary findings (coronary thrombus, ruptured plaque, or myocardial infarction [MI]) and their relation to SD. Autopsy results in 171 patients in the randomized ATLAS trial were reviewed. The prevalence of acute coronary findings was 33%: in 54% of patients with significant coronary artery disease (CAD) who died suddenly, 32% who died of myocardial failure, but in non-CAD patients, they were present in only 5% and 10% respectively. The percentage of patients classified as dying of MI was 28% in the autopsy group versus 4% in the nonautopsied group (P<0.0001). Of the autopsied group with acute MI, 97% (31 of 32 patients) with SD and 40% (6 of 15 patients) with myocardial failure did not have the MI diagnosed during life. When undiagnosed MI was classified as "sudden unexpected" or "myocardial failure" from clinical information only, the distribution of death causes was similar in the autopsy and nonautopsied groups.

CONCLUSIONS

Acute coronary findings are frequent and usually not clinically diagnosed in heart failure patients with CAD, particularly in those dying suddenly, suggesting the importance of acute coronary events as a trigger for SD in this setting.

The relationship of the erythrocyte sedimentation rate to inflammatory cytokines and survival in patients with chronic heart failure treated with angiotensin-converting enzyme inhibitors

OBJECTIVES

The object of the study was to assess the relationship between erythrocyte sedimentation rate (ESR) and inflammatory cytokine production in chronic heart failure (CHF). Our findings lead us to re-evaluate the prognostic value of the ESR in assessing patients with CHF.

BACKGROUND

The search for simple prognostic markers in CHF that can be assessed anywhere at low cost is important. Increases in ESR are related to the acute phase response in states of inflammation and infection.

METHODS

Initially, we studied ESR in relation to plasma levels of inflammatory cytokines in 58 CHF patients. The findings prompted us to analyze the mortality predictive power of ESR compared with established risk factors in these patients and (retrospectively) in a second group of 101 clinically stable CHF patients who had ESR measured.

RESULTS

In all 159 CHF patients (age 62+/-2 years, New York Heart Association [NYHA] class 2.7+/-0.1), ESR ranged from 1 to 96 mm/h (median 14 mm/h). The ESR was correlated with tumor necrosis factor (TNF)-alpha (r = 0.31, p<0.05), soluble TNF receptor-1 (r = 0.48, p<0.0005), soluble TNF receptor-2 (r = 0.39, p<0.005) and interleukin 6 (r = 0.45, p<0.005) levels. High ESR levels indicated a poor prognosis (p<0.0001), and this was independent of age, NYHA class, ejection fraction and peak oxygen consumption (p < 0.005). Patients with ESR above median (> or =15 mm/h) compared with patients with ESR <15 mm/h had an impaired survival (hazard ratio 2.62, 95% confidence interval 1.58-4.36, p<0.0001).

CONCLUSIONS

Our study demonstrates that in CHF a high ESR is an unfavorable prognostic sign, independent of patients' symptomatology and ventricular function. These results are in diametrical contrast to previous results. This may reflect a change in the underlying pathophysiology due to today's treatment with angiotensin-converting enzyme inhibitors.

Effect of losartan compared with captopril on mortality in patients with symptomatic heart failure: randomised trial--the Losartan Heart Failure Survival Study ELITE II

BACKGROUND

The ELITE study showed an association between the angiotensin II antagonist losartan and an unexpected survival benefit in elderly heart-failure patients, compared with captopril, an angiotensin-converting-enzyme (ACE) inhibitor. We did the ELITE II Losartan Heart Failure Survival Study to confirm whether losartan is superior to captopril in improving survival and is better tolerated.

METHODS

We undertook a double-blind, randomised, controlled trial of 3,152 patients aged 60 years or older with New York Heart Association class II-IV heart failure and ejection fraction of 40% or less. Patients, stratified for beta-blocker use, were randomly assigned losartan (n=1,578) titrated to 50 mg once daily or captopril (n=1,574) titrated to 50 mg three times daily. The primary and secondary endpoints were all-cause mortality, and sudden death or resuscitated arrest. We assessed safety and tolerability. Analysis was by intention to treat.

FINDINGS

Median follow-up was 555 days. There were no significant differences in all-cause mortality (11.7 vs 10.4% average annual mortality rate) or sudden death or resuscitated arrests (9.0 vs 7.3%) between the two treatment groups (hazard ratios 1.13 [95.7% CI 0.95-1.35], p=0.16 and 1.25 [95% CI 0.98-1.60], p=0.08). Significantly fewer patients in the losartan group (excluding those who died) discontinued study treatment because of adverse effects (9.7 vs 14.7%, p<0.001), including cough (0.3 vs 2.7%).

Survival of patients with a new diagnosis of heart failure: a population based study

OBJECTIVE

To describe the survival of a population based cohort of patients with incident (new) heart failure and the clinical features associated with mortality.

DESIGN

A population based observational study.

SETTING

Population of 151 000 served by 82 general practitioners in west London.

PATIENTS

New cases of heart failure were identified by daily surveillance of acute hospital admissions to the local district general hospital, and by general practitioner referral of all suspected new cases of heart failure to a rapid access clinic.

INTERVENTIONS

All patients with suspected heart failure underwent clinical assessment, and chest radiography, ECG, and echocardiogram were performed. A panel of three cardiologists reviewed all the data and determined whether the definition of heart failure had been met. Patients were subsequently managed by the general practitioner in consultation with the local cardiologist or admitting physician.

MAIN OUTCOME MEASURES

Death, overall and from cardiovascular causes.

RESULTS

There were 90 deaths (83 cardiovascular deaths) in the cohort of 220 patients with incident heart failure over a median follow up of 16 months. Survival was 81% at one month, 75% at three months, 70% at six months, 62% at 12 months, and 57% at 18 months. Lower systolic blood pressure, higher serum creatinine concentration, and greater extent of crackles on auscultation of the lungs were independently predictive of cardiovascular mortality (all p < 0.001).

CONCLUSIONS

In patients with new heart failure, mortality is high in the first few weeks after diagnosis. Simple clinical features can identify a group of patients at especially high risk of death.

Non-invasive assessment of vascular function; paradoxical vascular response to intravenous glucose in coronary heart disease

BACKGROUND

In healthy individuals, insulin administration causes an increase in forearm blood flow which is dependent on the effects of insulin on the vascular endothelium. Glucose, administered as an intravenous bolus, produces a transient hyperinsulinaemic response. We hypothesized that the insulin response to an intravenous glucose challenge during the intravenous glucose tolerance test might lead to increases in forearm blood flow in healthy individuals, and that such a response might be altered in patients with coronary heart disease.

METHODS AND RESULTS

Healthy individuals (n=10, aged 41.6+/-3. 0 years, mean+/-SEM) and patients with angiographically proven coronary heart disease (n=13, aged 65.5+/-2.4 years) underwent an intravenous glucose tolerance test with simultaneous measurement of right forearm blood flow at 28 time points, using mercury-in-silastic venous occlusion plethysmography. In controls, forearm blood flow increased to a mean of 31.7% above baseline values at 7 min and remained above baseline up to 180 min after intravenous glucose. In contrast, patients with coronary heart disease exhibited an opposite response, with forearm blood flow decreasing to a mean of -16.2% below baseline values at 7 min and -25.8% at 180 min. Marked group differences emerged in net changes from baseline in forearm blood flow throughout the intravenous glucose tolerance test, expressed as incremental areas under the forearm blood flow profiles (controls: +351.3+/-121.7; coronary heart disease patients: -244.3+/-72.4 min ml(-1). 100 ml(-1), P=0. 001).

CONCLUSIONS

We have demonstrated for the first time that in healthy individuals forearm blood flow increases after an intravenous bolus of glucose, and that paradoxically, this response is reduced below baseline forearm blood flow in patients with coronary heart disease. Further studies are needed to determine whether plethysmographic measurement of forearm blood flow after an intravenous bolus of glucose could provide a clinically useful non-invasive test for the diagnosis of occult coronary heart disease.

Oscillatory breathing patterns during wakefulness in patients with chronic heart failure: clinical implications and role of augmented peripheral chemosensitivity

BACKGROUND

Oscillatory breathing patterns characterized by rises and falls in ventilation with apnea (Cheyne-Stokes respiration [CSR]) or without apnea (periodic breathing [PB]) commonly occur during the daytime in chronic heart failure (CHF). We have prospectively characterized patients with cyclical breathing in terms of clinical characteristics, indices of autonomic control, prognosis, and the role of peripheral chemosensitivity.

METHODS AND RESULTS

To determine cyclical breathing pattern, power spectral analysis was applied to 30-minute recordings of respiration in 74 stable CHF patients. Analyses of heart rate variability and baroreflex sensitivity were used to assess autonomic balance. Peripheral chemosensitivity was assessed with the transient hypoxia method. We also determined whether the suppression of peripheral chemoreceptor activity (hyperoxia or dihydrocodeine) would influence the respiratory pattern. Cyclical respiration was found in 49 (66%) patients (22 [30%] CSR, 27 [36%] PB) and was associated with more advanced CHF symptoms, impaired autonomic balance, and increased chemosensitivity (0.80 and 0.75 versus 0.34 L. min(-1). %SaO(2)(-1), P<0.001, for CSR and PB versus normal breathing, respectively). Transient hyperoxia abolished oscillatory breathing in 7 of 8 patients. Dihydrocodeine administration decreased chemosensitivity by 42% (P=0.05), which correlated with improvement in respiratory pattern. Cyclical breathing predicted poor 2-year survival (relative risk 9.41, P<0.01, by Cox proportional hazards analysis), independent of peak oxygen consumption (P=0.04).

CONCLUSIONS

An oscillatory breathing pattern during the daytime is a marker of impaired autonomic regulation and poor outcome. Augmented activity of peripheral chemoreceptors may be involved in the genesis of this respiratory pattern. Modulation of peripheral chemosensitivity can reduce or abolish abnormal respiratory patterns and may be an option in the management of CHF patients with oscillatory breathing.

Comparative effects of low and high doses of the angiotensin-converting enzyme inhibitor, lisinopril, on morbidity and mortality in chronic heart failure. ATLAS Study Group

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors are generally prescribed by physicians in doses lower than the large doses that have been shown to reduce morbidity and mortality in patients with heart failure. It is unclear, however, if low doses and high doses of ACE inhibitors have similar benefits.

METHODS AND RESULTS

We randomly assigned 3164 patients with New York Heart Association class II to IV heart failure and an ejection fraction < or = 30% to double-blind treatment with either low doses (2.5 to 5.0 mg daily, n=1596) or high doses (32.5 to 35 mg daily, n=1568) of the ACE inhibitor, lisinopril, for 39 to 58 months, while background therapy for heart failure was continued. When compared with the low-dose group, patients in the high-dose group had a nonsignificant 8% lower risk of death (P=0.128) but a significant 12% lower risk of death or hospitalization for any reason (P=0.002) and 24% fewer hospitalizations for heart failure (P=0.002). Dizziness and renal insufficiency was observed more frequently in the high-dose group, but the 2 groups were similar in the number of patients requiring discontinuation of the study medication. Conclusions-These findings indicate that patients with heart failure should not generally be maintained on very low doses of an ACE inhibitor (unless these are the only doses that can be tolerated) and suggest that the difference in efficacy between intermediate and high doses of an ACE inhibitor (if any) is likely to be very small.