The second chance project: A multi-level examination of secondary prevention practices for Saudi people following a recent cardiac event

The study examined the health-related behaviours of Saudi people following a recent cardiac event and identified the factors that influence these behaviours using McLeroy et al.'s (1988) Ecological Model of Health Behaviours as a guiding framework. The study was one of the first in Saudi Arabia to examine the health-related behaviours of Saudi people following a recent cardiac event. The study findings emphasise the importance of a program that integrates secondary prevention practices, educational approaches and targeted supportive services in cardiac care in Saudi Arabia.

Inadvertent hypothermia after procedural sedation and analgesia in a cardiac catheterisation laboratory: A prospective observational study

Objective To identify the prevalence of and risk factors for inadvertent hypothermia after procedures performed with procedural sedation and analgesia in a cardiac catheterisation laboratory. Design Single-centre, prospective observational study. Setting Tertiary care private hospital in Australia. Participants A convenience sample of 399 patients undergoing elective procedures with procedural sedation and analgesia were included. Propofol infusions were used when an anaesthetist was present. Otherwise, bolus doses of either midazolam or fentanyl or a combination of these medications was used. Interventions None Measurements and main results Hypothermia was defined as a temperature <36.0° Celsius. Multivariate logistic regression was used to identify risk factors. Hypothermia was present after 23.3% (n=93; 95% confidence interval [CI] 19.2%-27.4%) of 399 procedures. Sedative regimens with the highest prevalence of hypothermia were any regimen that included propofol (n=35; 40.2%; 95% CI 29.9%-50.5%) and the use of fentanyl combined with midazolam (n=23; 20.3%; 95% CI 12.9%-27.7%). Difference in mean temperature from pre to post-procedure was -0.27°C (Standard deviation [SD] 0.45). Receiving propofol (odds ratio [OR] OR 4.6 95% CI 2.5-8.6), percutaneous coronary intervention (OR 3.2 95% CI 1.7-5.9), body mass index <25 (OR 2.5 95% CI 1.4-4.4) and being hypothermic prior to the procedure (OR 4.9; 95% CI 2.3-10.8) were independent predictors of post-procedural hypothermia. Conclusions A moderate prevalence of hypothermia was observed. The small absolute change in temperature observed may not be a clinically important amount. More research is needed to increase confidence in our estimates of hypothermia in sedated patients and its impact on clinical outcomes.

South Asians' cardiac medication adherence

Aim This paper is a report of a narrative review examining the current state of knowledge regarding adherence with cardiac medication among South Asian cardiac patients. Background South Asians experience higher rates of cardiovascular disease than any other ethnic group. South Asians may be less adherent with a cardiac medication regimen than Caucasians. The factors contributing to adherence are important to discover to assist South Asians to optimize their cardiac health. Data sources CINAHL, Medline (Ovid), PsychINFO, EMB Reviews-(Cochrane), and EMBASE were accessed using the key words: 'South Asian', 'Asia', 'East India', 'India', 'Pakistan', 'Bangladesh', 'Sri Lanka', 'medication compliance', 'medication noncompliance' and 'medication adherence'. English language papers published from January 1980 to January 2013 were eligible for inclusion. Review methods Abstracts were reviewed for redundancy and eligibility by the primary author. Manuscripts were then retrieved and reviewed for eligibility and validity by the first and last authors. Content analysis strategies were used for the synthesis. Results Thirteen papers were in the final data set; most were conducted in India and Pakistan. Medication side-effects, cost, forgetfulness and higher frequency of dosing contributed to non-adherence. South Asian immigrants also faced language barriers, which contributed to non-adherence. Knowledge regarding the medications prescribed was a factor that increased adherence. Conclusion South Asians' non-adherence to cardiac medications is multifaceted. How South Asians who newly immigrate to Western countries make decisions regarding their cardiac medication adherence ought to be explored in greater detail.

Australian patients using a cardiac-diabetes web-based intervention program: Contributions to person-centered clinical practice

Rationale, aims and objectives: Patients with both cardiac disease and diabetes have poorer health outcomes than patients with only one chronic condition. While evidence indicates that internet based interventions may improve health outcomes for patients with a chronic disease, there is no literature on internet programs specific to cardiac patients with comorbid diabetes. Therefore this study aimed to develop a specific web-based program, then to explore patients’ perspectives on the usefulness of a new program. Methods: The interpretive approach using semi-structured interviews on a purposive sample of eligible patients with type 2 diabetes and a cardiac condition in a metropolitan hospital in Brisbane, Australia. Thematic analysis was undertaken to describe the perceived usefulness of a newly developed Heart2heart webpage. Results: Themes identified included confidence in hospital health professionals and reliance on doctors to manage conditions. Patients found the webpage useful for managing their conditions at home. Conclusions: The new Heart2heart webpage provided a positive and useful resource. Further research on to determine the potential influence of this resource on patients’ self-management behaviours is paramount. Implications for practice include using multimedia strategies for providing information to patients’ comorbidities of cardiac disease and type 2 diabetes, and further development on enhancement of such strategies

Fractional diffusion models of cardiac electrical propagation: Role of structural heterogeneity in dispersion of repolarization

Impulse propagation in biological tissues is known to be modulated by structural heterogeneity. In cardiac muscle, improved understanding on how this heterogeneity influences electrical spread is key to advancing our interpretation of dispersion of repolarization. We propose fractional diffusion models as a novel mathematical description of structurally heterogeneous excitable media, as a means of representing the modulation of the total electric field by the secondary electrical sources associated with tissue inhomogeneities. Our results, analysed against in vivo human recordings and experimental data of different animal species, indicate that structural heterogeneity underlies relevant characteristics of cardiac electrical propagation at tissue level. These include conduction effects on action potential (AP) morphology, the shortening of AP duration along the activation pathway and the progressive modulation by premature beats of spatial patterns of dispersion of repolarization. The proposed approach may also have important implications in other research fields involving excitable complex media.

Use of observed within-person variation of cardiac troponin in emergency department patients for determination of biological variation and percentage and absolute reference change values

BACKGROUND Many patients presenting to the emergency department (ED) for assessment of possible acute coronary syndrome (ACS) have low cardiac troponin concentrations that change very little on repeat blood draw. It is unclear if a lack of change in cardiac troponin concentration can be used to identify acutely presenting patients at low risk of ACS. METHODS We used the hs-cTnI assay from Abbott Diagnostics, which can detect cTnI in the blood of nearly all people. We identified a population of ED patients being assessed for ACS with repeat cTnI measurement who ultimately were proven to have no acute cardiac disease at the time of presentation. We used data from the repeat sampling to calculate total within-person CV (CV(T)) and, knowing the assay analytical CV (CV(A)), we could calculate within-person biological variation (CV(i)), reference change values (RCVs), and absolute RCV delta cTnI concentrations. RESULTS We had data sets on 283 patients. Men and women had similar CV(i) values of approximately 14%, which was similar at all concentrations <40 ng/L. The biological variation was not dependent on the time interval between sample collections (t = 1.5-17 h). The absolute delta critical reference change value was similar no matter what the initial cTnI concentration was. More than 90% of subjects had a critical reference change value <5 ng/L, and 97% had values of <10 ng/L. CONCLUSIONS With this hs-cTnI assay, delta cTnI seems to be a useful tool for rapidly identifying ED patients at low risk for possible ACS.

A 2-hour diagnostic protocol for possible cardiac chest pain in the emergency department: A randomized clinical trial

IMPORTANCE Patients with chest pain represent a high health care burden, but it may be possible to identify a patient group with a low short-term risk of adverse cardiac events who are suitable for early discharge. OBJECTIVE To compare the effectiveness of a rapid diagnostic pathway with a standard-care diagnostic pathway for the assessment of patients with possible cardiac chest pain in a usual clinical practice setting. DESIGN, SETTING, AND PARTICIPANTS A single-center, randomized parallel-group trial with blinded outcome assessments was conducted in an academic general and tertiary hospital. Participants included adults with acute chest pain consistent with acute coronary syndrome for whom the attending physician planned further observation and troponin testing. Patient recruitment occurred from October 11, 2010, to July 4, 2012, with a 30-day follow-up. INTERVENTIONS An experimental pathway using an accelerated diagnostic protocol (Thrombolysis in Myocardial Infarction score, 0; electrocardiography; and 0- and 2-hour troponin tests) or a standard-care pathway (troponin test on arrival at hospital, prolonged observation, and a second troponin test 6-12 hours after onset of pain) serving as the control. MAIN OUTCOMES AND MEASURES Discharge from the hospital within 6 hours without a major adverse cardiac event occurring within 30 days. RESULTS Fifty-two of 270 patients in the experimental group were successfully discharged within 6 hours compared with 30 of 272 patients in the control group (19.3% vs 11.0%; odds ratio, 1.92; 95% CI, 1.18-3.13; P = .008). It required 20 hours to discharge the same proportion of patients from the control group as achieved in the experimental group within 6 hours. In the experimental group, 35 additional patients (12.9%) were classified as low risk but admitted to an inpatient ward for cardiac investigation. None of the 35 patients received a diagnosis of acute coronary syndrome after inpatient evaluation. CONCLUSIONS AND RELEVANCE Using the accelerated diagnostic protocol in the experimental pathway almost doubled the proportion of patients with chest pain discharged early. Clinicians could discharge approximately 1 of 5 patients with chest pain to outpatient follow-up monitoring in less than 6 hours. This diagnostic strategy could be easily replicated in other centers because no extra resources are required.

Comparative genomic analysis of human Chlamydia pneumoniae isolates from respiratory, brain and cardiac tissues

Chlamydia pneumoniae is an obligate intracellular bacterium implicated in a wide range of human diseases including atherosclerosis and Alzheimer's disease. Efforts to understand the relationships between C. pneumoniae detected in these diseases have been hindered by the availability of sequence data for non-respiratory strains. In this study, we sequenced the whole genomes for C. pneumoniae isolates from atherosclerosis and Alzheimer's disease, and compared these to previously published C. pneumoniae genomes. Phylogenetic analyses of these new C. pneumoniae strains indicate two sub-groups within human C. pneumoniae, and suggest that both recombination and mutation events have driven the evolution of human C. pneumoniae. Further fine-detailed analyses of these new C. pneumoniae sequences show several genetically variable loci. This suggests that similar strains of C. pneumoniae are found in the brain, lungs and cardiovascular system and that only minor genetic differences may contribute to the adaptation of particular strains in human disease.

PW376 A pilot study of a post-discharge nurse-led, educational intervention on cardiac self-efficacy and anxiety in post-PCI patients

Introduction Hospitalisation for percutaneous coronary intervention (PCI) is often short, with limited nurse-teaching time and poor information absorption. Currently, patients are discharged home only to wait up to 4-8 weeks to commence a secondary prevention program and visit their cardiologist. This wait is an anxious time for patients and confidence or self-efficacy (SE) to self-manage may be low. Objectives To determine the effects of a nurse-led, educational intervention on participant SE and anxiety in the early post-discharge period. Methods A pilot study was undertaken as a randomised controlled clinical trial. Thirty-three participants were recruited, with n=13 randomised to the intervention group. A face-to-face, nurse-led, educational intervention was undertaken within the first 5-7 days post-discharge. Intervention group participants received standard post-discharge education, physical assessment, with a strong focus on the emotional impact of cardiovascular events and PCI. Early reiteration of post-discharge education was offered, along with health professional support with the aim to increase patients’ SE and to effectively manage their post-discharge health and well being, as well as anxieties. Self-efficacy to return to normal activities was measured to gauge participants’ abilities to manage post-PCI after attending the intervention using the cardiac self-efficacy (CSE) scale. State and trait anxiety was also measured using the State-Trait Anxiety Inventory (STAI) to determine if an increase in SE would influence participant anxiety. Results There were some increases in mean CSE scores in the intervention group participants over time. Areas of increase included return to normal social activities and confidence to change diet. Although reductions were observed in mean state and trait anxiety scores in both groups, an overall larger reduction in intervention group participants was observed over time. Conclusion It is essential that patients are given the education, support, and skills to self-manage in the early post-discharge period so that they have greater SE and are less anxious. This study provides some initial evidence that nurse-led support and education during this period, particularly the first week following PCI, is beneficial and could be trialled using alternate modes of communication to support remote and rural PCI patients and extend to other cardiovascular patients.

Can nurses do more for patients to reduce vascular access and cardiac complications following PCI?

Percutaneous coronary interventions have increased 50% in Australia, yet vascular and cardiac complications remain ongoing outcome issues for patients. Managing complications is confounded by reduced length of patient stay, yet is an integral component of a cardiac nurses’ scope of practice. The aim of this study was to highlight in and out of hospital vascular and cardiac complications, for twelve months post patient discharge after PCI. Prospective data was collected from the hospital angioplasty database from 1089 consecutive patients who had PCI procedures from 1 January 2005 to 31 December 2006. In hospital vascular complications were reported by 391 (35%) of the 1089 patients, following PCI. Of these, 22.4% had haemorrhage only, 7.1% haematoma only. Cardiac complications in hospital were, one death (0.09%) following PCI, three deaths (0.27%) during the same admission and no incidence of myocardial infarction or bypass surgery. Patients who had PCI in 2005 (525) were telephone followed up after discharge at one and twelve months. Surprisingly, ongoing vascular outcomes were noted, with a 2.5% incidence at one month and 4% at 12 months. Cardiac complications were also identified, 51 (9.7%) patients requiring readmission for repeat angiogram, 19 (3.6%) a repeat PCI and 7 (1.3%) patients undergoing bypass surgery. This review highlights that vascular and cardiac problems are ongoing issues for PCI patients both in and out of hospital. The results suggest that cardiac nurses focus more on improving the monitoring and discharge care of patients and families for recovery after PCI.

Pain location, distribution and intensity after cardiac surgery

Research Review on: Mueller X, Tinguely F, Tevaearai H, Revelly J, Chiolero R & Von Segess L. Pain location, distribution and intensity after cardiac surgery. Chest 2000; 118(2):391.396.

Sampling Methods for Exploring Between Subject Variability in Cardiac Electrophysiology Experiments

Between-subject and within-subject variability is ubiquitous in biology and physiology and understanding and dealing with this is one of the biggest challenges in medicine. At the same time it is difficult to investigate this variability by experiments alone. A recent modelling and simulation approach, known as population of models (POM), allows this exploration to take place by building a mathematical model consisting of multiple parameter sets calibrated against experimental data. However, finding such sets within a high-dimensional parameter space of complex electrophysiological models is computationally challenging. By placing the POM approach within a statistical framework, we develop a novel and efficient algorithm based on sequential Monte Carlo (SMC). We compare the SMC approach with Latin hypercube sampling (LHS), a method commonly adopted in the literature for obtaining the POM, in terms of efficiency and output variability in the presence of a drug block through an in-depth investigation via the Beeler-Reuter cardiac electrophysiological model. We show improved efficiency via SMC and that it produces similar responses to LHS when making out-of-sample predictions in the presence of a simulated drug block.

The impact of inter-fraction set-up errors on the probability of pulmonary and cardiac complication in left-sided breast cancer patients

Purpose This study evaluated the impact of patient set-up errors on the probability of pulmonary and cardiac complications in the irradiation of left-sided breast cancer. Methods and Materials Using the CMS XiO Version 4.6 (CMS Inc., St Louis, MO) radiotherapy planning system's NTCP algorithm and the Lyman -Kutcher-Burman (LKB) model, we calculated the DVH indices for the ipsilateral lung and heart and the resultant normal tissue complication probabilities (NTCP) for radiation-induced pneumonitis and excess cardiac mortality in 12 left-sided breast cancer patients. Results Isocenter shifts in the posterior direction had the greatest effect on the lung V20, heart V25, mean and maximum doses to the lung and the heart. Dose volume histograms (DVH) results show that the ipsilateral lung V20 tolerance was exceeded in 58% of the patients after 1cm posterior shifts. Similarly, the heart V25 tolerance was exceeded after 1cm antero-posterior and left-right isocentric shifts in 70% of the patients. The baseline NTCPs for radiation-induced pneumonitis ranged from 0.73% - 3.4% with a mean value of 1.7%. The maximum reported NTCP for radiation-induced pneumonitis was 5.8% (mean 2.6%) after 1cm posterior isocentric shift. The NTCP for excess cardiac mortality were 0 % in 100% of the patients (n=12) before and after setup error simulations. Conclusions Set-up errors in left sided breast cancer patients have a statistically significant impact on the Lung NTCPs and DVH indices. However, with a central lung distance of 3cm or less (CLD <3cm), and a maximum heart distance of 1.5cm or less (MHD<1.5cm), the treatment plans could tolerate set-up errors of up to 1cm without any change in the NTCP to the heart.

On the order of the fractional Laplacian in determining the spatio-temporal evolution of a space-fractional model of cardiac electrophysiology

Space-fractional operators have been used with success in a variety of practical applications to describe transport processes in media characterised by spatial connectivity properties and high structural heterogeneity altering the classical laws of diffusion. This study provides a systematic investigation of the spatio-temporal effects of a space-fractional model in cardiac electrophysiology. We consider a simplified model of electrical pulse propagation through cardiac tissue, namely the monodomain formulation of the Beeler-Reuter cell model on insulated tissue fibres, and obtain a space-fractional modification of the model by using the spectral definition of the one-dimensional continuous fractional Laplacian. The spectral decomposition of the fractional operator allows us to develop an efficient numerical method for the space-fractional problem. Particular attention is paid to the role played by the fractional operator in determining the solution behaviour and to the identification of crucial differences between the non-fractional and the fractional cases. We find a positive linear dependence of the depolarization peak height and a power law decay of notch and dome peak amplitudes for decreasing orders of the fractional operator. Furthermore, we establish a quadratic relationship in conduction velocity, and quantify the increasingly wider action potential foot and more pronounced dispersion of action potential duration, as the fractional order is decreased. A discussion of the physiological interpretation of the presented findings is made.