Evidence based drug therapy : are optimal doses and multiple medication therapies realistic in patients with chronic heart failure

Background: Chronic Heart Failure (CHF) has a high mortality and morbidity. Large scale randomised controlled trials have proven the benefits of beta blockade and ACE inhibitors in reducing mortality in patients with CHF and expert guidelines mandate their use. In spite of these recommendations, important therapies are under-prescribed and under-utilised.

Method: 1015 consecutive patients enrolled in CHF management programs across Australia were surveyed during 2005-2006 to determine prescribing patterns in heart failure medications. These patients were followed-up for a period of 6 months.

Results: The survey revealed that beta blockers were prescribed to 80% of patients (more than 85% were on sub-optimal doses) and 70% were prescribed Angiotensin converting enzyme (ACE) inhibitors (approximately 50% were on sub-optimal dose). 19% of patients were prescribed Angiotensin receptor blockers (ARBs). By 6 months <25% of the patients who were on sub-optimal dose beta blockers or ACE inhibitors at baseline, had been up-titrated to maximum dose (p<0.0001). In CHF programs, were nurses were able to titrate medications, 75% of patients reached optimal dose of beta blockers compared to those programs with no nurse-led medication titration, where only 25% of patients reached optimal dose (p<0.004). When examining optimal dosage for any two of these mandatory medications, less patients were on optimal therapy. Beta blockers and ACE inhibitors, were both prescribed in combination in 60% of patients. While beta blockers and ARBs were prescribed to 15% of patients.

Conclusion: Whilst prescribing rates for a single medication strategy of beta blockers, or ACE inhibitors were greater than 70%, an increase in dosage of these medications and utilisation of proven combination therapy of these medications was poor. It is suggested that clinical outcomes for this cohort of patients could be further improved by adherence to evidence-based practice, ESC guidelines, and optimisation of these medications by heart failure nurses in a CHF program. On the basis of these findings and in the absence of ready access to a polypill, focussing on evidence-based practice to increase utilisation and optimal dosage of combination medication therapy is critical.

Heterogeneity in service delivery and inequity in access are common characteristics of chronic heart failure management programs

Background: The prevalence of heart failure in Australia is similar to that of Europe. In Australia, chronic heart failure management programs (CHF-MPs) have become part of standard care for patients with Chronic Heart Failure (CHF). However, heterogeneity among programs is common which can result in variable patient outcomes.

Method: A national survey was undertaken of 59 post-discharge CHF-MPs identified from within the Australian health care system. Two had ceased operating and one centre declined to participate in the study. A 33-item investigator-developed questionnaire, examining the characteristics and interventions used within each CHF-MP, was sent to the remaining 56 CHF-MPs. A response rate of 100% was achieved.

Results: Our survey revealed a disproportional distribution of CHF-MPs across the Australian continent: the State of Victoria had 3.6 CHF-MPs/million population, New South Wales had 3.7 CHF-MPs/million population, Queensland had 1 program/million population, South Australia had 0.3 CHF-MPs/million population and Western Australia had 1 program/million population.Overall, 8000 postdischarge CHF pts (median: 126; IQR: 26-260) were managed via CHF-MPs. Approximately 40,000 CHF pts are discharged from metropolitan institutions nationally, this represents only 22% of the potential caseload for these cost-effective CHF-MPs. Only 8% of these programs were located within rural regions. The majority of CHF-MPs were located within an acute metropolitan hospital (52%) and 36% were community based (all associated with a hospital). Heterogeneity of CHF-MPs in applied models of care was evident with 75% of CHF-MPs offering CHF outpatient clinics and 77% conducting home visits. Of the programs offering home visits 78% were funded by regional government (p<0.048). There were no nurse-led CHF outpatient clinics. A hybrid approach to CHF-MPs was common with many CHF-MPs comprising an outpatient clinic, home visits and inpatient visits. Various medications were titrated by nurses in 43% of CHF-MPs. In the programs that allowed nurses to titrate medications 79% were located in an acute hospital (p<0.011).

Conclusion: Variability of service availability is of concern within the context of universal coverage. In addition, heterogeneity between programs and the diversity in models of care delivery highlights the inconsistency and questions the quality of health related outcomes. We are currently analysing health outcome data from the 1015 patients managed in these CHF-MPs to describe the relationship between quality of care and health outcomes.

Molecular cloning of natriuretic peptides from the heart of reptiles : loss of ANP in diapsid reptiles and birds

Atrial natriuretic peptide (ANP) and B-type NP (BNP) are hormones involved in homeostatic control of body fluid and cardiovascular regulation. Both ANP and BNP have been cloned from the heart of mammals, amphibians, and teleost fishes, while an additional cardiac peptide, ventricular NP, has been found in selected species of teleost fish. However, in chicken, BNP is the primary cardiac peptide identified thus far. In contrast, the types of NP/s present in the reptilian heart are unknown, representing a considerable gap in our understanding of NP evolution. In the present study, we cloned and sequenced a BNP cDNA from the atria of representative species of reptile, including crocodile, lizard, snake, and tortoise. In addition, we cloned BNP from the pigeon atria. The reptilian and pigeon BNP cDNAs had ATTTA repeats in the 3′ untranslated region, as observed in all vertebrate BNP mRNAs. A high sequence homology was evident when comparing reptile and pigeon preproBNP with the previously identified chicken preproBNP. In particular, the predicted mature BNP-29 was identical between crocodile, tortoise, and chicken, with pigeon having a single amino acid substitution; lizard and snake BNP had seven and nine substitutions, respectively. Furthermore, an ANP cDNA could only be cloned from the tortoise atria. Since ANP was not isolated from the heart of any non-chelonian reptile and appears to be absent in birds, we propose that the ANP gene has been lost after branching of the turtles in the amniote line. This data provides new avenues for research on NP function in reptiles.

Identifying the health and mental health information needs of people with coronary heart disease, with and without depression

Objective:
To identify the health and mental health information needs of people with coronary heart disease (CHD), with and without comorbid depression.

Design and setting:
A qualitative study conducted in Melbourne in 2006, using thematic analysis of semi-structured interviews on the types of health information that patients with CHD considered useful to assist with the management of their illness. Structured clinical interviews were used to assess current and prior depressive episodes in these patients.

Participants:
14 general practice patients (eight with current or prior history of major depression) who had experienced myocardial infarction, coronary artery bypass graft surgery, angioplasty or angina (confirmed via testing).

Results:
Four themes relating to information on how patients could manage their cardiovascular health and improve their psychosocial wellbeing emerged: psychosocial; physical activity; medical; and information for family. The most prominent information needs included identification and management of risk-related physical symptoms, and psychosocial information, most notably to enhance patients’ social support. Patients considered this information important for alleviating health anxiety and negative affect.

Conclusion:
This small patient sample endorsed the need for health and mental health information on a range of psychosocial and physical health topics. Participants desired specific types of information to assist with the self-management of their health and to assuage their health concerns.

Current developments and future challenges for the creation of aortic heart valve

The concept of tissue-engineered heart valves offers an alternative to current heart valve replacements that is capable of addressing shortcomings such as life-long administration of anticoagulants, inadequate durability, and inability to grow. Since tissue engineering is a multifaceted area, studies conducted have focused on different aspects such as hemodynamics, cellular interactions and mechanisms, scaffold designs, and mechanical characteristics in the form of both in vitro and in vivo investigations. This review concentrates on the advancements of scaffold materials and manufacturing processes, and on cell–scaffold interactions. Aside from the commonly used materials, polyglycolic acid and polylactic acid, novel polymers such as hydrogels and trimethylene carbonate-based polymers are being developed to simulate the natural mechanical characteristics of heart valves. Electrospinning has been examined as a new manufacturing technique that has the potential to facilitate tissue formation via increased surface area. The type of cells utilized for seeding onto the scaffolds is another factor to take into consideration; currently, stem cells are of great interest because of their potential to differentiate into various types of cells. Although extensive studies have been conducted, the creation of a fully functional heart valve that is clinically applicable still requires further investigation due to the complexity and intricacies of the heart valve.