Potential benefits of precision medicine in cardiovascular disease (CVD) include more accurate phenotyping of individual patients with the same condition or presentation, using multiple clinical, imaging, molecular and other variables to guide diagnosis and treatment. An approach to realising this potential is the digital twin concept, whereby a virtual representation of a patient is constructed and receives real-time updates of a range of data variables in order to predict disease and optimise treatment selection for the real-life patient. We explored the term digital twin, its defining concepts, the challenges as an emerging field, and potentially important applications in CVD. A mapping review was undertaken using a systematic search of peer-reviewed literature. Industry-based participants and patent applications were identified through web-based sources. Searches of Compendex, EMBASE, Medline, ProQuest and Scopus databases yielded 88 papers related to cardiovascular conditions (28%, n = 25), non-cardiovascular conditions (41%, n = 36), and general aspects of the health digital twin (31%, n = 27). Fifteen companies with a commercial interest in health digital twin or simulation modelling had products focused on CVD. The patent search identified 18 applications from 11 applicants, of which 73% were companies and 27% were universities. Three applicants had cardiac-related inventions. For CVD, digital twin research within industry and academia is recent, interdisciplinary, and established globally. Overall, the applications were numerical simulation models, although precursor models exist for the real-time cyber-physical system characteristic of a true digital twin. Implementation challenges include ethical constraints and clinical barriers to the adoption of decision tools derived from artificial intelligence systems.

Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy. Pharmacists performed pulse palpation and iECG recordings, with cardiologist iECG over-reading. General practitioner review/12-lead ECG was facilitated for suspected new AF. An automated AF algorithm was retrospectively applied to collected iECGs. Cost-effectiveness analysis incorporated costs of iECG screening, and treatment/outcome data from a United Kingdom cohort of 5,555 patients with incidentally detected asymptomatic AF. A total of 1,000 pharmacy customers aged ≥65 years (mean 76 ± 7 years; 44% male) were screened. Newly identified AF was found in 1.5% (95% CI, 0.8–2.5%); mean age 79 ± 6 years; all had CHA₂DS₂-VASc score ≥2. AF prevalence was 6.7% (67/1,000). The automated iECG algorithm showed 98.5% (CI, 92–100%) sensitivity for AF detection and 91.4% (CI, 89–93%) specificity. The incremental cost-effectiveness ratio of extending iECG screening into the community, based on 55% warfarin prescription adherence, would be $AUD5,988 (€3,142; $USD4,066) per Quality Adjusted Life Year gained and $AUD30,481 (€15,993; $USD20,695) for preventing one stroke. Sensitivity analysis indicated cost-effectiveness improved with increased treatment adherence. Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered. Previous Presentation: This study was presented in part as an oral presentation at the Cardiac Society of Australia and New Zealand Conference; 9 August 2013; Sydney, Australia, abstract published in Heart Lung Circulation 2013;22:S223. Trial registration: Australian New Zealand clinical trials registry: ACTRN12612000406808.

Background: Participation in cardiac rehabilitation (CR) benefits patients with coronary heart disease (CHD), yet worldwide only some 15–30% of those eligible attend. To improve understanding of the reasons for poor participation we undertook a systematic review and meta-synthesis of the qualitative literature. Methods: Qualitative studies identifying patient barriers and enablers to attendance at CR were identified by searching multiple electronic databases, reference lists, relevant conference lists, grey literature, and keyword searching of the internet (1990–2010). Studies were selected if they included patients with CHD and reviewed experience or understanding about CR. Meta-synthesis was used to review the papers and to synthesize the data. Results: From 1165 papers, 34 unique studies were included after screening. These included 1213 patients from eight countries. Study methodology included interviews (n = 25), focus groups (n = 5), and mixed-methods (n = 4). Key reasons for not attending CR were physical barriers, such as lack of transport, or financial cost, and personal barriers, such as embarrassment about participation, or misunderstanding the reasons for onset of CHD or the purpose of CR. Conclusions: There is a vast amount of qualitative research which investigates patients’ reasons for non-attendance at CR. Key issues include system-level and patient-level barriers, which are potentially modifiable. Future research would best be directed at investigating strategies to overcome these barriers.

Summary: Atrial fibrillation (AF) is associated with a significantly increased stroke risk which is highly preventable with appropriate oral anticoagulant therapy (OAC). However, AF may be asymptomatic and unrecognised prior to stroke. We aimed to determine if single time-point screening for AF could identify sufficient numbers with previously undiagnosed AF, to be effective for stroke prevention. This is a systematic review of clinical trials, by searching electronic medical databases, reference lists and grey literature. Studies were included if they evaluated a general ambulant adult population, using electrocardiography or pulse palpation to identify AF. We identified 30 individual studies (n=122,571, mean age 64 years, 54% male) in nine countries. Participants were recruited either from general practitioner and outpatient clinics (12 studies) or population screening/community advertisements (18 studies). Prevalence of AF across all studies was 2.3% (95% CI, 2.2–2.4%), increasing to 4.4% (CI, 4.1–4.6%) in those ≥65 years (16 studies, n= 27,884). Overall incidence of previously unknown AF (14 studies, n=67,772) was 1.0% (CI, 0.89–1.04%), increasing to 1.4% (CI, 1.2–1.6%) in those ≥65 years (8 studies, n= 18,189) in whom screening setting did not influence incidence identified. Of those with previously unknown AF, 67% were at high risk of stroke. Screening can identify 1.4% of the population ≥65 years with previously undiagnosed AF. Many of those identified would be eligible for, and benefit from OAC to prevent stroke. Given this incidence, community AF screening strategies in at risk older age groups could potentially reduce the overall health burden associated with AF.

Background: Mobile technologies are innovative, scalable approaches to reducing risk of cardiovascular disease but evidence related to effectiveness and acceptability remains limited. We aimed to explore the effectiveness, acceptability and usefulness of mobile applications (apps) for cardiovascular disease self-management and risk factor control. Design: Systematic review with meta-synthesis of quantitative and qualitative data. Methods: Comprehensive search of multiple databases (Medline, Embase, CINAHL, SCOPUS and Cochrane CENTRAL) and grey literature. Studies were included if the intervention was primarily an app aimed at improving at least two lifestyle behaviours in adults with cardiovascular disease. Meta-synthesis of quantitative and qualitative data was performed to review and evaluate findings. Results: Ten studies of varying designs including 607 patients from five countries were included. Interventions targeted hypertension, heart failure, stroke and cardiac rehabilitation populations. Factors that improved among app users were rehospitalisation rates, disease-specific knowledge, quality of life, psychosocial well-being, blood pressure, body mass index, waist circumference, cholesterol and exercise capacity. Improved physical activity, medication adherence and smoking cessation were also characteristic of app users. Appealing app features included tracking healthy behaviours, self-monitoring, disease education and personalised, customisable content. Small samples, short duration and selection bias were noted limitations across some studies, as was the relatively low overall scientific quality of evidence. Conclusions: Multiple behaviours and cardiovascular disease risk factors appear modifiable in the shorter term with use of mobile apps. Evidence for effectiveness requires larger, controlled studies of longer duration, with emphasis on process evaluation data to better understand important system- and patient-level characteristics.

When implemented in practice, digital technologies have shown improvements in morbidity and mortality outcomes in patients with cardiovascular disease (CVD). For scholars, research into digital technologies in cardiovascular care has been relatively recent, thus it is important to understand the history of digital health technology in cardiovascular research—its emergence, rate of growth, hot topics, and its temporal evolution. The aim of this study was to analyse more than 16,000 articles in this domain based on their scientometric indicators. Web of Science (WoS) Core Collection was accessed and searched at several levels, including titles, abstracts, keywords, authors, sources and individual articles. Analysis examined the temporal shifts in research and scholarly focus based on keywords, networks of collaboration, topical divisions in relation to digital technologies, and influential publications. Findings showed this research area is growing exponentially. Co-citation analysis revealed twenty prominent research streams and identified variation in the magnitude of activities in each stream. A recent emergence of research activities in digital technology in cardiovascular rehabilitation (CR), out-of-hospital cardiac arrest (OHCA), and arrythmia research was also demonstrated. Conversely, wearable technologies, activity tracking and electronic medical records research are now past their peak of reported research activity. With increasing amounts of novel technologies becoming available and more patients taking part in remote health care monitoring, further evaluation and research into digital technologies, including their long-term effectiveness, is needed. Furthermore, emerging technologies, which are evaluated and/or validated should be considered for implementation into clinical practice as treatment and prevention modalities for CVD.