Ethnic differences in the prevalence and aetiology of left ventricular systolic dysfunction in the community: the Harrow heart failure watch

Highlighting the South Asian Heart Failure Epidemic

Heart failure (HF) remains a progressive syndrome with high morbidity and mortality, and accounts for many hospitalisations globally with a downstream impact of increasing healthcare costs. South Asian individuals account for most of the global burden of non-communicable diseases. In this systematic review, a literature search was performed for all studies focusing on South Asians and HF using PubMed as the primary research tool and citations were included from relevant MEDLINE-indexed journals. Upon identification of relevant studies, pertinent data points were extracted systematically from each eligible study. South Asians have an earlier age of onset of many non-communicable diseases compared to other ethnic groups worldwide, including cardiovascular disease (CVD). Given the large number of South Asians impacted by CVD and both traditional and non-traditional risk factors for CVD, HF has the potential to become an epidemic among South Asians across the world. Individuals of South Asian origin are at elevated risk for CVD compared to many other populations and should be followed closely for the potential development of HF. This review describes what is unique to South Asian individuals at risk for and with established HF, as well as management and prognostic considerations. Future directions and potential policy changes are highlighted that can reduce the HF burden among South Asians globally.

Prevalence and demographic variation of cardiovascular, renal, metabolic, and mental health conditions in 12 million english primary care records

BACKGROUND

Primary care electronic health records (EHR) are widely used to study long-term conditions in epidemiological and health services research. Therefore, it is important to understand how well the recorded prevalence of these conditions in EHRs, compares to other reliable sources overall, and varies by socio-demographic characteristics. We aimed to describe the prevalence and socio-demographic variation of cardiovascular, renal, and metabolic (CRM) and mental health (MH) conditions in a large, nationally representative, English primary care database and compare with prevalence estimates from other population-based studies.

METHODS

This was a cross-sectional study using the Clinical Practice Research Datalink (CPRD) Aurum primary care database. We calculated prevalence of 18 conditions and used logistic regression to assess how this varied by age, sex, ethnicity, and socio-economic status. We searched the literature for population prevalence estimates from other sources for comparison with the prevalences in CPRD Aurum.

RESULTS

Depression (16.0%, 95%CI 16.0-16.0%) and hypertension (15.3%, 95%CI 15.2-15.3%) were the most prevalent conditions among 12.4 million patients. Prevalence of most conditions increased with socio-economic deprivation and age. CRM conditions, schizophrenia and substance misuse were higher in men, whilst anxiety, depression, bipolar and eating disorders were more common in women. Cardiovascular risk factors (hypertension and diabetes) were more prevalent in black and Asian patients compared with white, but the trends in prevalence of cardiovascular diseases by ethnicity were more variable. The recorded prevalences of mental health conditions were typically twice as high in white patients compared with other ethnic groups. However, PTSD and schizophrenia were more prevalent in black patients. The prevalence of most conditions was similar or higher in the primary care database than diagnosed disease prevalence reported in national health surveys. However, screening studies typically reported higher prevalence estimates than primary care data, especially for PTSD, bipolar disorder and eating disorders.

CONCLUSIONS

The prevalence of many clinically diagnosed conditions in primary care records closely matched that of other sources. However, we found important variations by sex and ethnicity, which may reflect true variation in prevalence or systematic differences in clinical presentation and practice. Primary care data may underrepresent the prevalence of undiagnosed conditions, particularly in mental health.

Are there patients missing from community heart failure registers? An audit of clinical practice

BACKGROUND

General practitioners in the UK are financially incentivised, via the Quality Outcomes Framework, to maintain a record of all patients at their practice with heart failure and manage them appropriately. The prevalence of heart failure recorded in primary care registers (0.7-1.0%) is less than reported in epidemiological studies (3-5%). Using an audit of clinical practice, we set out to investigate if there are patients 'missing' from primary care heart failure registers and what the underlying mechanisms might be.

DESIGN

The design of this study was as an audit of clinical practice at a UK general practice ( n = 9390).

METHODS

Audit software (ENHANCE-HF) was used to identify patients who may have heart failure via a series of hierarchical searches of electronic records. Heart failure was then confirmed or excluded based on the electronic records by a heart failure specialist nurse and patients added to the register. Outcome data for patients without heart failure was collected after two years.

RESULTS

Heart failure prevalence was 0.63% at baseline and 1.12% after the audit. Inaccurate coding accounted for the majority of missing patients. Amongst patients without heart failure who were taking a loop diuretic, the rate of incident heart failure was 13% and the rate of death or hospitalization with heart failure was 25% respectively during two-year follow-up.

CONCLUSION

There are many patients missing from community heart failure registers which may detriment patient outcome and practice income. Patients without heart failure who take loop diuretics are at high risk of heart failure-related events.

Serum N1-methylnicotinamide is Associated with Left Ventricular Systolic Dysfunction in Chinese

We previously reported that serum N¹-methylnicotinamide (me-NAM), an indicator of nicotinamide N-methyltransferase (NNMT) activity, was associated with obesity, diabetes, and coronary artery disease in Chinese patients. However, whether NNMT might play a role in the development of heart failure remains to be elucidated. In this study, the associations between levels of serum me-NAM and left ventricular structure and function were investigated in Chinese patients. Serum me-NAM was measured by liquid chromatography-mass spectrometry in 265 subjects. M-mode, 2-dimensional and Doppler echocardiography were performed with the GE Vivid E9 system to assess left ventricular structure and function. Of note, the participants in the top tertile of me-NAM had the lowest left ventricular ejection fraction (LVEF), preload recruitable stroke work (PRSW), and highest prevalence of left ventricular systolic dysfunction (LVSD). Serum me-NAM was negatively correlated with LVEF and PRSW before and after adjusted for potential confounding variables (P ≤ 0.02). In multiple logistic regression analyses, the subjects in the top tertile of me-NAM had highest risks for LVSD (OR 6.80; 95% CI 1.26–36.72; P = 0.026), which was also observed in continuous analyses (OR 9.48; 95% CI 1.41–63.48; P = 0.02). In conclusion, serum me-NAM is negatively associated with LVEF and PRSW and accordingly positively associated with the prevalence of LVSD in Chinese patients.

Epidemiology of heart failure: the prevalence of heart failure and ventricular dysfunction in older adults over time. A systematic review

The 'epidemic' of heart failure seems to be changing, but precise prevalence estimates of heart failure and left ventricular dysfunction (LVD) in older adults, based on adequate echocardiographic assessment, are scarce. Systematic reviews including recent studies on the prevalence of heart failure and LVD are lacking. We aimed to assess the trends in the prevalence of LVD, and heart failure with reduced (HFrEF) and preserved ejection fraction (HFpEF) in the older population at large. A systematic electronic search of the databases Medline and Embase was performed. Studies that reported prevalence estimates in community-dwelling people ≥60 years old were included if echocardiography was used to establish the diagnosis. In total, 28 articles from 25 different study populations were included. The median prevalence of systolic and 'isolated' diastolic LVD was 5.5% (range 3.3-9.2%) and 36.0% (range 15.8-52.8%), respectively. A peak in systolic dysfunction prevalence seems to have occurred between 1995 and 2000. 'All type' heart failure had a median prevalence rate of 11.8% (range 4.7-13.3%), with fairly stable rates in the last decade and with HFpEF being more common than HFrEF [median prevalence 4.9% (range 3.8-7.4%) and 3.3% (range 2.4-5.8%), respectively]. Both LVD and heart failure remain common in the older population at large. The prevalence of diastolic dysfunction is on the rise and currently higher than that of systolic dysfunction. The prevalence of the latter seems to have decreased in the 21st century.

Cardiovascular Disease in South Asian Migrants

Cardiovascular disease (CVD) represents a significant cause of global mortality and morbidity. South Asians (SAs) have a particularly high burden of coronary artery disease (CAD). This review describes current literature regarding the prevalence, incidence, etiology, and prognosis of CVD in SA migrants to high-income nations. We conducted a narrative review of CVD in the SA diaspora through a search of MEDLINE and PubMed. We included observational studies, randomized clinical trials, nonsystematic reviews, systematic reviews, and meta-analyses written in English. Of 15,231 articles identified, 827 articles were screened and 124 formed the basis for review. SA migrants have a 1.5-2 times greater prevalence of CAD than age- and sex-adjusted Europids. Increased abdominal obesity and body fat and increased burden of type 2 diabetes mellitus and dyslipidemia appear to be primary drivers of the excess CAD burden in SAs. Sedentary lifestyle and changes in diet after immigration are important contributors to weight gain and adiposity. Early life factors, physical activity patterns and, in some cases, reduced adherence to medical therapy may contribute to increased CVD risks in SAs. Novel biomarkers like leptin and adipokines may show distinct patterns in SAs and provide insights into cardiometabolic risk determinants. In conclusion, SAs have distinct CVD risk predispositions, with a complex relationship to cultural, innate, and acquired factors. Although CVD risk factor management and treatment among SAs is improving, opportunities exist for further advances.

Hyperglycemia has a greater impact on left ventricle function in South Asians than in Europeans

OBJECTIVE Diabetes is associated with left ventricular (LV) diastolic and systolic dysfunction. South Asians may be at particular risk of developing LV dysfunction owing to a high prevalence of diabetes. We investigated the role of diabetes and hyperglycemia in LV dysfunction in a community-based cohort of older South Asians and white Europeans. RESEARCH DESIGN AND METHODS Conventional and Doppler echocardiography was performed in 999 participants (542 Europeans and 457 South Asians aged 58-86 years) in a population-based study. Anthropometry, fasting bloods, coronary artery calcification scoring, blood pressure, and renal function were measured. RESULTS Diabetes and hyperglycemia across the spectrum of HbA1c had a greater adverse effect on LV function in South Asians than Europeans (N-terminal-probrain natriuretic peptide β ± SE 0.09 ± 0.04, P = 0.01, vs. -0.04 ± 0.05, P = 0.4, P for HbA1c/ethnicity interaction 0.02), diastolic function (E/e' 0.69 ± 0.12, P < 0.0001, vs. 0.09 ± 0.2, P = 0.6, P for interaction 0.005), and systolic function (s' -0.11 ± 0.06, P = 0.04, vs. 0.14 ± 0.09, P = 0.1, P for interaction 0.2). Multivariable adjustment for hypertension, microvascular disease, LV mass, coronary disease, and dyslipidemia only partially accounted for the ethnic differences. Adverse LV function in diabetic South Asians could not be accounted for by poorer glycemic control or longer diabetes duration. CONCLUSIONS Diabetes and hyperglycemia have a greater adverse effect on LV function in South Asians than Europeans, incompletely explained by adverse risk factors. South Asians may require earlier and more aggressive treatment of their cardiometabolic risk factors to reduce risks of LV dysfunction.

Heart failure in South Asia

South Asia (SA) is both the most populous and the most densely populated geographical region in the world. The countries in this region are undergoing epidemiological transition and are facing the double burden of infectious and non-communicable diseases.

Heart failure (HF) is a major and increasing burden all over the world. In this review, we discuss the epidemiology of HF in SA today and its impact in the health system of the countries in the region. There are no reliable estimates of incidence and prevalence of HF (heart failure) from this region.

The prevalence of HF which is predominantly a disease of the elderly is likely to rise in this region due to the growing age of the population. Patients admitted with HF in the SA region are relatively younger than their western counterparts. The etiology of HF in this region is also different from the western world. Untreated congenital heart disease and rheumatic heart disease still contribute significantly to the burden of HF in this region. Due to epidemiological transition, the prevalence of hypertension, diabetes mellitus, obesity and smoking is on the rise in this region. This is likely to escalate the prevalence of HF in South Asia.

We also discuss potential developments in the field of HF management likely to occur in the nations in South Asia. Finally, we discuss the interventions for prevention of HF in this region

Multiscale modeling and data integration in the virtual physiological rat project

It has become increasingly evident that the descriptions of many complex diseases are only possible by taking into account multiple influences at different physiological scales. To do this with computational models often requires the integration of several models that have overlapping scales (genes to molecules, molecules to cells, cells to tissues). The Virtual Physiological Rat (VPR) Project, a National Institute of General Medical Sciences (NIGMS) funded National Center of Systems Biology, is tasked with mechanistically describing several complex diseases and is therefore identifying methods to facilitate the process of model integration across physiological scales. In addition, the VPR has a considerable experimental component and the resultant data must be integrated into these composite multiscale models and made available to the research community. A perspective of the current state of the art in model integration and sharing along with archiving of experimental data will be presented here in the context of multiscale physiological models. It was found that current ontological, model and data repository resources and integrative software tools are sufficient to create composite models from separate existing models and the example composite model developed here exhibits emergent behavior not predicted by the separate models.

Heart failure among South Asians: a narrative review of risk, nature, outcomes and management

Individuals of South Asian descent have a high prevalence of comorbidities that are risk factors for the development of heart failure (HF), including diabetes mellitus and metabolic syndrome. However, little is known about the prevalence of HF, its management and prognosis for this population compared to Caucasians. Therefore, a literature review relating to the nature, outcome and treatment of HF in South Asian patients compared to Caucasians was conducted. It was anticipated that collating existing studies in this manner would be useful for guiding professionals in managing HF within this ethnic group, given that to achieve optimal care, regimens need to take into account cultural differences that may impact on adherence. Reviewed literature showed that South Asians with HF were more likely to be younger and have diabetes and hypertension. These papers also implied that outcomes for South Asians with HF were similar or even better than for Caucasians. The review highlighted the under-representation of South Asians in HF trials, meaning that evidence-based recommendations tailored to this specific population are limited. This is an important consideration because ethnic differences in response to medication have been reported; it cannot be assumed that treatments shown to work for Caucasians will be efficacious for those from minority ethnic groups.

Systolic heart failure in South Asians

Heart failure (HF) is a common condition leading to an unfavourable prognosis and impaired quality of life. In this review, we provide an overview of published literature on possible epidemiological and pathophysiological differences between patients with systolic HF of South Asian origin and those from other ethnic groups (mainly White). Systolic HF tends to manifest earlier among South Asians and with frequent hospital admissions. However, survival for such patients appears to be significantly better compared with the White group, which might be associated with different patterns of HF. For example, this could be attributed to a lower prevalence of left ventricular systolic dysfunction in South Asian subjects. Indeed, the high prevalence of hypertension and diabetes among South Asians may predispose to diastolic HF with preserved systolic function. In addition, because of underrepresentation of South Asians in clinical trials, there are little data on optimal management of this ethnic group.

Prevalence of heart failure and atrial fibrillation in minority ethnic subjects: the Ethnic-Echocardiographic Heart of England Screening Study (E-ECHOES)

BACKGROUND

Limited data exists on the prevalence of heart failure amongst minority groups in the UK. To document the community prevalence and severity of left ventricular systolic dysfunction, heart failure, and atrial fibrillation, amongst the South Asian and Black African-Caribbean groups in the UK.

METHODS AND RESULTS

We conducted a cross-sectional study recruiting from September 2006 to July 2009 from 20 primary care centres in Birmingham, UK. 10,902 eligible subjects invited, 5,408 participated (49.6%) and 5,354 had complete data (49.1%). Subjects had median age 58.2 years (interquartile range 51.0 to 70.0), and 2544 (47.5%) were male. Of these, 1933 (36.3%) had BMI>30 kg/m(2), 1,563 (29.2%) had diabetes, 2676 (50.0%) had hypertension, 307 (5.7%) had a history of myocardial infarction, and 104 (1.9%) had history of arrhythmia. Overall, 59 (1.1%) had an Ejection Fraction<40%, and of these 40 (0.75%) were NYHA class ≥2; 51 subjects (0.95%) had atrial fibrillation. Of the remaining 19 patients with an EF<40%, only 4 patients were treated with furosemide. A further 54 subjects had heart failure with preserved ejection fraction.

CONCLUSIONS

This is the largest study of the prevalence of left ventricular systolic dysfunction, heart failure and atrial fibrillation in under-researched minority communities in the UK. The prevalence of heart failure in these minority communities appears comparable to that of the general population but less than anticipated given the high rates of cardiovascular disease in these groups. Heart failure continues to be a major cause of morbidity in all ethnic groups and preventive strategies need to be identified and implemented.

Association of 25 bp deletion in MYBPC3 gene with left ventricle dysfunction in coronary artery disease patients

Rationale

Mutations in MYBPC3 encoding cardiac myosin binding protein C are common genetic cause of hereditary cardiac myopathies. An intronic 25-bp deletion in MYBPC3 at 3′ region is associated with dilated (DCM) and hypertrophic (HCM) cardiomyopathies in Southeast Asia. However, the frequency of MYBPC3 25 bp deletion and associated clinical presentation has not been established in an unrelated cohort of left ventricular dysfunction (LVD) secondary to coronary artery disease (CAD) patients.

Objective

We sought to determine the role of MYBPC3 25 bp polymorphism on LVD in two cohorts of CAD patients.

Methods and Results

The study included 265 consecutive patients with angiographically confirmed CAD and 220 controls. MYBPC3 25 bp polymorphism was determined by polymerase chain reaction. Our results showed that carrier status of MYBPC3 25 bp deletion was associated with significant compromised left ventricle ejection fraction (LVEF ≤45) in CAD patients (p value  =  <0.001; OR = 4.49). To validate our results, we performed a replication study in additional 140 cases with similar clinical characteristics and results again confirmed consistent findings (p = 0.029; OR = 3.3). Also, presence of the gene deletion did not have significant association in CAD patients with preserved ejection fraction (LVEF>45) (p value  = 0.1; OR  = 2.3).

Conclusion

The frequency of MYBPC3 DW genotype and D allele was associated with compromised LVEF implying that genetic variants of MYBPC3 encoding mutant structural sarcomere protein could increase susceptibility to left ventricular dysfunction. Therefore, 25 bp deletion in MYBPC3 may represent a genetic marker for cardiac failure in CAD patients from Southeast Asia.

Cost‐Effective Strategies to Screen for Left Ventricular Systolic Dysfunction in the Community—A Concept

Early detection of heart failure caused by left ventricular systolic dysfunction (LVSD) is important, since early treatment has been shown to retard the progression of heart failure. While traditional echocardiography remains the standard for the detection of LVSD, electrocardiography and serum brain natriuretic peptide have also been shown to predict LVSD. Recently, hand-held echocardiography systems have been shown to have high predictive accuracy for assessment of LVSD. With the availability of the above bedside and relatively less-costly techniques, compared with traditional echocardiography, the major question now is what is the most cost-effective strategy for screening subjects for LVSD. To date, no studies have systematically addressed this issue, but preliminary data are becoming available. This review article discusses the pros and cons of various investigative strategies and likely cost-effectiveness of each strategy to screen for LVSD.

Nuclear Cardiology: Present and Future

Nuclear cardiology has made significant advances since the first reports of planar scintigraphy for the evaluation of left ventricular perfusion and function. While the current "state of the art" of gated myocardial perfusion single-photon emission computed tomographic (SPECT) imaging offers invaluable diagnostic and prognostic information for the evaluation of patients with suspected or known coronary artery disease (CAD), advances in the cellular and molecular biology of the cardiovascular system have helped to usher in a new modality in nuclear cardiology, namely, molecular imaging. In this review, we will discuss the current state of the art in nuclear cardiology, which includes SPECT and positron emission tomographic evaluation of myocardial perfusion, evaluation of left ventricular function by gated myocardial perfusion SPECT and gated blood pool SPECT, and the evaluation of myocardial viability with PET and SPECT methods. In addition, we will discuss the future of nuclear cardiology and the role that molecular imaging will play in the early detection of CAD at the level of the vulnerable plaque, the evaluation of cardiac remodeling, and monitoring of important new therapies including gene therapy and stem cell therapy.

What is the most cost-effective strategy to screen for left ventricular systolic dysfunction: natriuretic peptides, the electrocardiogram, hand-held echocardiography, traditional echocardiography, or their combination?

AIMS

To assess the screening characteristics and cost-effectiveness of screening for left ventricular systolic dysfunction (LVSD) in community subjects.

METHODS AND RESULTS

A total of 1392 members of the general public and 928 higher risk subjects were randomly selected from seven community practices. Attending subjects underwent an ECG, N-terminal pro-brain natriuretic peptide (NTproBNP) serum levels, and traditional echocardiography (TE). A total of 533 consecutive subjects underwent hand-held echocardiography (HE). The screening characteristics and cost-effectiveness (cost per case of LVSD diagnosed) of eight strategies to predict LVSD (LVSD <45% on TE) were compared. A total of 1205 subjects attended. Ninety six per cent of subjects with LVSD in the general population had identifiable risk factors. All screening strategies gave excellent negative predictive value. Screening high-risk subjects was most cost-effective, screening low-risk subjects least cost-effective. TE screening was the least cost-effective strategy. NTproBNP screening gave similar cost savings to ECG screening; HE screening greater cost-savings, and HE screening following NTproBNP or ECG pre-screening the greatest cost-savings, costing approximately 650 Euros per case of LVSD diagnosed in high-risk subjects (63% cost-savings vs.TE).

CONCLUSION

Thus several different modalities allow cost-effective community-based screening for LVSD, especially in high-risk subjects. Such programmes would be cost-effective and miss few cases of LVSD in the community.