Applying evidence-based device care in cardiovascular patients: which patient with heart failure and what device?

In terms of engineering, clinical understanding and application, device therapy remains in its infancy. In clinical trials, implantable cardiac defibrillators (ICDs) have greatly reduced the rate of sudden death and had a modest impact on mortality in a relatively broad range of patients. They do not generally improve symptoms and may make them worse. Cardiac resynchronisation therapy (CRT) devices have been used more selectively - probably far too selectively - and have shown substantial improvement in symptoms and a large reduction in mortality both by reducing sudden death and death due to heart failure. These effects are not explained solely by improved ventricular function, and the clinical response to therapy has so far not been predicted well by any method of assessing cardiac function or dyssynchrony. Reduction in brady-arrhythmia-triggered sudden death may be an underestimated benefit of biventricular pacing. In recent trials, heart failure patients implanted with a device have had a remarkably low mortality. This forces the clinical community to contemplate universal device use for patients with heart failure, except in those who have irremediable, life-limiting, non-cardiac disease. For most patients this should be CRT or a combination of CRT and an ICD (CRT-D).

Telehealth – Future Directions in Cardiovascular Care

Over recent years, telehealth has increasingly demonstrated its value in supporting the delivery of cardiovascular healthcare. From teletriage services as a portal into healthcare through to telemonitoring of heart failure patients, technology is already increasing the ability of practitioners to provide care remotely, empower patients and improve clinical outcomes. In the future, telehealth services have the potential to have an even greater impact on the provision of cardiovascular care. Embedding telehealth services into mainstream cardiac care, the development of more sophisticated devices and the utilisation of technology in a wider range of clinical contexts will help to accelerate the adoption of telehealth throughout healthcare. This article evaluates the current state of the art in telehealth provision and explores some of the areas for future development in this fast-moving and exciting area of clinical practice.

Management strategies in unstable coronary artery disease--current problems and future directions. The UCAD Council

Unstable coronary artery disease continues to pose a major challenge to clinicians. The advent of new therapies, such as percutaneous transluminal coronary angioplasty, low-molecular-weight heparins, and glycoprotein IIb/IIIa inhibitors, provides new management options for this indication but also raises new questions with regard to optimal management. Prospective randomized trials with well-defined, long-term outcome measures and a means of identifying which patients will derive most benefit from each treatment, together with a means of rapid and clear dissemination of study results and implications, are required in order to advance the management of unstable coronary artery disease.

The control of adrenergic function in heart failure: therapeutic intervention

Chronic heart failure is characterised by excess adrenergic activity that augurs a poor prognosis. The reasons for increased adrenergic activity are complex and incompletely understood. The circumstantial evidence relating increased activity to adverse outcome is powerful, but not yet conclusive. In normal subjects, autonomic control of the circulation is predominantly under the control of sympatho-inhibitory inputs from the arterial and cardiopulmonary baroreceptors, with a small input from the excitatory ergo- and chemo-receptors. In heart failure, the situation is reversed, with loss of the restraining input from the baroreceptors and an increase in the excitatory inputs, resulting in excessive adrenergic activity. The circumstantial evidence linking neuroendocrine activation with poor outcome coupled with the clinical success of inhibition of the renin-angiotensin-aldosterone system has long suggested that inhibition of adrenergic activity might be beneficial in heart failure. There is a number of potential ways of achieving this. Improved treatment of heart failure itself may reduce sympathetic drive. There is an interplay between angiotensin II, aldosterone and the sympathetic nervous system, and thus RAAS antagonists, such as angiotensin converting enzyme inhibitors and spironolactone could directly reduce sympathetic activation. Exercise rehabilitation may similarly reduce sympathetic activity.Recently, beta-adrenergic receptor antagonists have been conclusively shown to improve symptoms, reduce hospitalisations and increase survival. However, the demonstration that central reduction of sympathetic activity with agents such as moxonidine increases morbidity and mortality suggests that we do not properly understand the role of sympathetic activation in the pathophysiology of heart failure.

Polypharmacy (or polytherapy) in the treatment of heart failure

There is now conclusive evidence that most patients with heart failure due to left ventricular systolic dysfunction should be treated with angiotensin converting enzyme (ACE) inhibitors and beta-blockers. They will also need diuretics for the control of fluid retention. There is also a powerful case for adding spironolactone to the treatment of patients with more severe symptoms. Many doctors would also use digoxin and, especially if coronary disease is present, aspirin or warfarin. Most patients also have other chronic diseases, such as diabetes, arthritis, depression and dyspepsia, and each of these may provoke the prescription of yet another agent. Many patients will receive prescriptions to treat the side-effects of their therapy. Finding a sure path through the morass of pharmacotherapy is a daunting task. Polypharmacy is having a negative impact on new drug research in an area where there are in fact remarkably few really effective treatments and the therapeutic problem is only partially solved. This paper discusses some of the issues surrounding polypharmacy in heart failure and how to resolve them, using an illustrative case history. It highlights the potential benefits of polypharmacy with effective drugs and the gross over-use of ineffective treatments in heart failure. The major problem with polypharmacy in heart failure is not the heart failure treatment itself, but the drugs for other concomitant conditions, the effectiveness of which is often not supported by an appropriate evidence base and for which alternative, less noxious management strategies often exist. Polypharmacy may be deleterious not only because of the increased potential for side-effects and drug interactions but also because taking unnecessary therapy reduces compliance with effective drugs.

Analysis of failure time hierarchical data in the presence of competing risks with application to oral contraceptive pill use in Egypt

Problems of practical interest in the analysis of data on contraceptive use, from Demographic and Health Surveys (DHS), include the estimation of the cause-specific probability of discontinuation by time t (the cumulative incidence function), in the presence of other competing causes and the evaluation of the effect of covariates on the cause-specific hazards of discontinuation. Methods of analysis of failure time data with competing risks are by now fairly well developed in the case of a simple random sample. However, the data from the DHS are clustered by geographical areas and include multiple episodes per woman. For a marginal (population average) approach, we propose using methods developed for simple random samples with standard errors calculated using a double bootstrap to take account of the clustered hierarchical nature of the data. In the conditional approach, the cause-specific hazards are modelled as log-linear functions of the covariates conditional on random effects of clusters and women, using a three-level multinomial discrete-time logit model. The methods are applied to data from Egypt 1992 DHS on the oral contraceptive pill use.

Clinical trials update: highlights of the scientific sessions of the XXIII Congress of the European Society of Cardiology--WARIS II, ESCAMI, PAFAC, RITZ-1 and TIME

This article continues a series of reports updating recent research developments of particular interest to personnel involved in the treatment and management of patients with heart failure. This is a summary of selected presentations made at the Scientific Sessions of the XXIII Annual Congress of the European Society of Cardiology. Summaries of the following clinical studies are included: WARIS-II, ESCAMI, PAFAC, RITZ-I and TIME.

Validation of an echocardiographic wall motion index in heart failure due to ischaemic heart disease

AIMS

The echocardiographic assessment of left ventricular ejection fraction (LVEF) by geometric methods is limited in many patients because of inadequate views and also in the presence of regional wall motion abnormalities due to ischaemic heart disease (IHD). This study aimed to examine the application of a wall motion index (WMI) method, using a nine-segment LV model in patients with chronic heart failure (CHF) due to IHD.

METHODS AND RESULTS

Echocardiography was performed in 71 consecutive subjects with CHF due to IHD. WMI could be derived in 70 subjects (99%). The inter-observer variability (repeatability coefficient) of WMI was 0.66, i.e. LVEF+/-20%. In 66 subjects, LVEF was measured, within 4 weeks, using radionuclide ventriculography (RNV-EF). The inter-observer variability of RNV-EF was +/-3.1%. Using the mean of two observations for each method, the Bland-Altman range of agreement for LVEF was 26% (+/-13%).

CONCLUSION

WMI is a widely applicable echocardiographic method for assessing LV systolic function and has moderate agreement with RNV-EF. Unlike RNV-EF, however, WMI is not likely to be a suitable method for the measurement of small, but prognostically important, changes in LV function that may occur in CHF.

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.

Does aspirin attenuate the effect of angiotensin-converting enzyme inhibitors in hypertension or heart failure?

There is a wealth of data that suggests an important interaction between aspirin and angiotensin-converting enzyme inhibitors in patients with chronic stable cardiovascular disease. The interaction is less obvious in the postinfarction setting, possibly reflecting the fact that many patients stop their aspirin therapy within a few months of such an event. An interaction is biologically plausible, because there is considerable evidence that angiotensin-converting enzyme inhibitors exert important effects through increasing the production of vasodilator prostaglandins, whereas aspirin blocks their production through inhibition of cyclooxygenase, even at low doses. There is some evidence that low-dose aspirin may raise systolic and diastolic blood pressure. There is also considerable evidence that aspirin may entirely neutralize the clinical benefits of angiotensin-converting enzyme inhibitors in patients with heart failure. In addition, aspirin may have an adverse effect on outcome in patients with heart failure that is independent of any interaction with angiotensin-converting enzyme inhibitors, possibly by blocking endogenous vasodilator prostaglandin production and enhancing the vasoconstrictor potential of endothelin. The evidence is not sufficient to justify advising long-term aspirin therapy for patients with cardiovascular disease in general, and for those with heart failure in particular. Thus, the lack of evidence of benefit with aspirin in patients with heart failure and coronary disease, along with growing evidence that aspirin is directly harmful in patients with heart failure and that aspirin may negate the benefits of angiotensin-converting enzyme inhibitors suggest that, unless there is an opportunity to randomize the patient into a study of antithrombotic strategies, then aspirin should be withdrawn or possibly substituted with an anticoagulant or an antiplatelet agent that does not block cyclooxygenase. In contrast, there is fairly robust evidence for a benefit of both aspirin and angiotensin-converting enzyme inhibitors during the first 5 weeks after a myocardial infarction, with little evidence of an interaction. The combination of aspirin and angiotensin-converting enzyme inhibitors is warranted during this period, after which discontinuation or substitution of aspirin with another agent should be considered.

The link between postnatal abstinence and extramarital sex in Côte d'Ivoire

Whether the link, found in Benin, between postnatal abstinence and husbands' extramarital contacts can be generalized to other West African countries is assessed in this study. Data from the 1994 Demographic and Health Survey, Côte d'Ivoire, obtained from monogamous husbands concerning their extramarital sexual behavior in the two months preceding the survey were linked to data reported by wives concerning postnatal abstinence over the same time period. Logistic regression was applied to assess the link between these two factors, net of the effects of possible confounders. A significant effect of postnatal abstinence on the probability that the husband reported at least one extramarital partner was found. Unprotected extramarital sex was two times more common among men who observed conjugal abstinence than it was among other men. Other predictors of extramarital sex were urban-rural residence, region, education, and whether or not husband and wife had the same religious affiliation. Because condom use is low in this population, the protective effect of marital abstinence is offset by an increased probability that husbands will seek extramarital partners during the postpartum period. The results confirm the earlier findings for Benin and can likely be generalized to most of West Africa.

Reproductive health needs of young persons in markets and motor parks in south west Nigeria

The aim of the study was to assess the reproductive health needs of out-of-school males and females aged 12-26 years working in markets and motor parks in Ibadan using Focus Group Discussions (FGD) and a survey questionnaire. Result revealed that sexual experience was higher among males (80%) compared to females (66%). Multiple concurrent sexual partnerships were found to be common among unmarried young men (71%) than women (51%) but means to prevent pregnancy or sexually transmitted disease (STD) were rarely employed. The knowledge of HIV was high (70%) though very few (12%) were aware that an infected individual would remain asymtomatic. Moreover, 36.5% thought that condoms make sex less enjoyable. Between 6 and 9% used a method for disease prevention within marriage or regular partnerships compared to 16% in casual contacts. Despite high exposure to risk, the prevalence of STDs was low as only 4% of the sexually experienced males and 9% of females were infected with Candida Albicans, Chlamydia trachomatis and Trichomonas vaginitis or Neisseria gonorrhea. The ready availability of antibiotics may account for this apparent discrepancy. These findings suggest that out of school adolescents working in motor parks needs sexuality education and counseling backed up with clinical services.

Clinical Trials Update: CAPRICORN, COPERNICUS, MIRACLE, STAF, RITZ-2, RECOVER and RENAISSANCE and cachexia and cholesterol in heart failure. Highlights of the Scientific Sessions of the American College of Cardiology, 2001

This is a synopsis of presentations made at the American College of Cardiology (ACC) in 2001 summarising recent research developments relating to heart failure. Clinical studies of particular interest to physicians with an interest in heart failure and its prevention are reviewed. The COPERNICUS trial lends further support to the use of the beta-blocker, carvedilol, in severe heart failure and the CAPRICORN trial to its use in patients with post-infarction left ventricular systolic dysfunction. The MIRACLE study reinforces the evidence from three smaller trials that cardiac resynchronisation therapy is an effective treatment for the relief of symptoms in patients with severe heart failure and cardiac dyssynchrony. The STAF trial casts further doubt on the wisdom of cardioversion as a routine strategy for the management of chronic atrial fibrillation. The RITZ-2 trial suggests that an intravenous, non-selective endothelin antagonist is effective in improving haemodynamics and symptoms and possibly in reducing morbidity in severe heart failure. Observational studies in heart failure suggest that a moderate excess of body fat and elevated blood cholesterol may be desirable in patients with heart failure, challenging the current non-evidenced-based vogue for cholesterol lowering therapy in heart failure. The RENAISSANCE and RECOVER outcome studies of etanercept, a tumour necrosis factor (TNF) receptor analogue that blocks the effect of TNF, were stopped because of lack of evidence of benefit shortly after the ACC.