Ethnic variability in mortality from ischaemic heart disease/cardiomegaly in Malaysia.

The prevalence of ischaemic heart disease with associated cardiomegaly and other chronic diseases such as diabetes mellitus has increased in Malaysia in recent years. As the contribution to mortality from ischaemic heart disease/cardiomegaly in different ethnic populations is unclear, a three year (January 2013-December 2015) retrospective study of autopsy cases was undertaken at the Department of Forensic Pathology, University Malaya Medical Centre. There were 80 cases with lethal ischaemic heart diseases/cardiomegaly. The age range was 30-69 years (mean 50.19 years) with a male to female ratio of 39:01. The most vulnerable age was 50-59 years accounting for 38.75% of cases. Malays accounted for 15% of cases, Indians for 32.5% and Chinese for 36.25%. Although in 35 cases (43.75%) there was a history suggestive of ischaemic heart disease, the remaining 45 cases (56.25%) were apparently healthy until the terminal collapse. It appears that Indian males in the 50-59 year age range are most at risk for lethal cardiac events in this population, most often with no preceding symptoms or signs. The study demonstrates the value of studying subpopulations for disease risk rather than relying on accrued general population data.

Factors Associated With Left Atrial Remodeling in the General Population.

BACKGROUND: Although contributors to remodeling of the left ventricle (LV) have been well studied in general population cohorts, few data are available describing factors influencing changes in left atrial (LA) structure. METHODS AND RESULTS: Maximum LA volume was determined by cardiac magnetic resonance imaging among 748 participants in the Dallas Heart Study at 2 visits a mean of 8 years apart. Associations of changes in LA volume (ΔLAV) with traditional risk factors, biomarkers, LV geometry, and remodeling by cardiac magnetic resonance imaging and detailed measurements of global and regional adiposity (by magnetic resonance imaging and dual-energy x ray absorptiometry) were assessed using multivariable linear regression. Greater ΔLAV was independently associated with black and Hispanic race/ethnicity, change in systolic blood pressure, LV mass and ΔLV mass, N-terminal probrain natriuretic peptide and change in N-terminal probrain natriuretic peptide, and body mass index (P<0.05 for each). In subanalyses, the associations of ΔLAV with LV mass parameters were driven by associations with baseline and ΔLV end diastolic volume (P<0.0001 for each) and not wall thickness (P=0.21). Associations of ΔLAV with body mass index were explained exclusively by associations with visceral fat mass (P=0.002), with no association seen between ΔLAV and subcutaneous abdominal fat (P=0.47) or lower body fat (P=0.30). CONCLUSIONS: Left atrial dilatation in the population is more common in black and Hispanic than in white individuals and is associated with parallel changes in the LV. LA dilatation may be mediated by blood pressure control and the development of visceral adiposity.

Salt-sensitive hypertension and cardiac hypertrophy in transgenic mice expressing a corin variant identified in blacks.

Blacks represent a high-risk population for salt-sensitive hypertension and heart disease, but the underlying mechanism remains unclear. Corin is a cardiac protease that regulates blood pressure by activating natriuretic peptides. A corin gene variant (T555I/Q568P) was identified in blacks with hypertension and cardiac hypertrophy. In this study, we tested the hypothesis that the corin variant contributes to the hypertensive and cardiac hypertrophic phenotype in vivo. Transgenic mice were generated to express wild-type (WT) or T555I/Q568P variant corin in the heart under the control of α-myosin heavy chain promoter. The mice were crossed into a corin knockout (KO) background to create KO/TgWT and KO/TgV mice that expressed WT or variant corin, respectively, in the heart. Functional studies showed that KO/TgV mice had significantly higher levels of proatrial natriuretic peptide in the heart compared with that in control KO/TgWT mice, indicating that the corin variant was defective in processing natriuretic peptides in vivo. By radiotelemetry, corin KO/TgV mice were found to have hypertension that was sensitive to dietary salt loading. The mice also developed cardiac hypertrophy at 12 to 14 months of age when fed a normal salt diet or at a younger age when fed a high-salt diet. The phenotype of salt-sensitive hypertension and cardiac hypertrophy in KO/TgV mice closely resembles the pathological findings in blacks who carry the corin variant. The results indicate that corin defects may represent an important mechanism in salt-sensitive hypertension and cardiac hypertrophy in blacks.

Cardiac adaptation in athletes of black ethnicity: differentiating pathology from physiology.

Cardiac adaptation to intense physical exercise is determined by factors including age, gender, body size, sporting discipline and ethnicity. Differentiating physiology from pathological conditions such as hypertrophic cardiomyopathy (HCM) is challenging, but relevant, as HCM remains the commonest cause of sudden death in young athletes. Marked electrocardiographic repolarisation changes and echocardiographic left ventricular hypertrophy have been demonstrated in athletes of black ethnicity. Such changes highlight the overlap between 'athlete's heart' and morphologically mild HCM with potential for false-positive diagnoses and disqualification from competitive sport. The focus of this article is to provide practical considerations in differentiating physiological adaptation to exercise from cardiac pathology in athletes of black ethnicity.

Differences in the incidence of congestive heart failure by ethnicity: the multi-ethnic study of atherosclerosis.

BACKGROUND: The relationship between incident congestive heart failure (CHF) and ethnicity as well as racial/ethnic differences in the mechanisms leading to CHF have not been demonstrated in a multiracial, population-based study. Our objective was to evaluate the relationship between race/ethnicity and incident CHF. METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) is a cohort study of 6814 participants of 4 ethnicities: white (38.5%), African American (27.8%), Hispanic (21.9%), and Chinese American (11.8%). Participants with a history of cardiovascular disease at baseline were excluded. Cox proportional hazards models were used for data analysis. RESULTS: During a median follow-up of 4.0 years, 79 participants developed CHF (incidence rate: 3.1 per 1000 person-years). African Americans had the highest incidence rate of CHF, followed by Hispanic, white, and Chinese American participants (incidence rates: 4.6, 3.5, 2.4, and 1.0 per 1000 person-years, respectively). Although risk of developing CHF was higher among African American compared with white participants (hazard ratio, 1.8; 95% confidence interval, 1.1-3.1), adding hypertension and/or diabetes mellitus to models including ethnicity eliminated statistical ethnic differences in incident CHF. Moreover, African Americans had the highest proportion of incident CHF not preceded by clinical myocardial infarction (75%) compared with other ethnic groups (P = .06). CONCLUSIONS: The higher risk of incident CHF among African Americans was related to differences in the prevalence of hypertension and diabetes mellitus as well as socioeconomic status. The mechanisms of CHF also differed by ethnicity; interim myocardial infarction had the least influence among African Americans, and left ventricular mass increase had the greatest effect among Hispanic and white participants.

Determinants and prognostic importance of cardiomegaly among new ESRD patients in the United States.

PURPOSE: Cardiomegaly is a radiographic abnormality of major prognostic importance in the general population. We explored the clinical correlations and mortality impact of cardiomegaly in new end-stage renal disease (ESRD) patients from the Dialysis Morbidity and Mortality Study Wave 2. METHODS: Radiographic data denoting the presence or absence of cardiomegaly were available for 97% (n=3908) of the entire cohort. Multivariate logistic regression explored relationships between potential uremic factors and known traditional cardiovascular disease (CVD) factors with cardiomegaly and Cox regression estimated the mortality risk associations over 2 years. RESULTS: The prevalence of cardiomegaly was 26%. Multivariate analysis identified: age (adjusted odds ratio [OR]=1.30 per 10 years older), black race (OR=1.33) diabetes (OR=1.26), hypertension (OR=1.28), tobacco use (OR=1.17), serum albumin (OR=1.36 per 1 g/dL lower), and extremes of body mass index (BMI) (OR=1.24 for BMI<21.1 and OR=1.10 for BMI>30.0 compared with referent [21.1-23.3 Kg/m2]) as significant correlates. The impact of cardiomegaly on mortality was greatest in the first 12 months (RR=1.56; CI, 1.33-1.83) and persisted for up to 2 years (RR=1.44; CI, 1.27-1.62). Interestingly, the likelihood of cardiomegaly was significantly lower for patients who received regular care during the pre-ESRD period (erythropoietin use [OR=0.79] and nephrology visits [OR=0.80 for > or =2 vs. less]). CONCLUSIONS: Traditional CVD risk factors were the predominant correlates of cardiomegaly in new ESRD patients. Vigorous CVD risk factor reduction strategies and frequent specialist care during the pre-ESRD period may be beneficial in reducing the prevalence of cardiomegaly and attenuating its impact on survival.

Left ventricular hypertrophy in black and white hypertensives. Standard electrocardiographic criteria overestimate racial differences in prevalence.

OBJECTIVE: To assess racial differences in the accuracy of standard electrocardiographic (ECG) criteria in the diagnosis of left ventricular hypertrophy (LVH). DESIGN: The sensitivity and specificity of standard ECG criteria were compared in blacks and whites using echocardiographic LVH as the reference standard. SETTING: Eight worksite-based hypertension clinics in New York, NY. PATIENTS: A sample of 122 black and 148 white hypertensive patients. RESULTS: The prevalence of ECG-LVH was two to six times higher in blacks than in whites, depending on the criteria used (range, 6% to 24% in blacks vs 1% to 7% in whites; P = .0005 to .19 for black-white comparisons). The difference in prevalence of echocardiographic LVH [corrected], however, was less striking and did not attain statistical significance (26% in blacks and 20% in whites; P greater than .2). The sensitivity of the ECG was low (range, 3% to 17%) and did not differ significantly between the two races for any of the conventional criteria; specificity, however, was lower in blacks for all criteria (range, 73% to 94% vs 95% to 100% for whites; P = .0001 to .09). The predictive value of a positive ECG was consistently, although not significantly, lower in the black subjects. Black race was the strongest independent predictor of decreased ECG specificity in multiple logistic regression analysis that also considered age, gender, body mass index, left ventricular mass index, and smoking. CONCLUSIONS: Commonly used ECG criteria for the detection of LVH have a poor sensitivity in both black and white hypertensives and a lower specificity in blacks than in whites; this may lead to a greater number of false-positive diagnoses in black patients, as well as to an overestimation of black-white difference in LVH prevalence.

Hypertensive heart disease in African-Americans.

Hypertensive heart disease is a frequent complication in hypertensive African-Americans because of inadequate high blood pressure control. Moreover, African-Americans may be predisposed to develop LVH earlier in life and more readily than Caucasians, and it may be more malignant. The appearance of both LVH and congestive heart failure are ominous developments in individual patients, and early detection of LVH is mandatory for adequate management and reversal of this complication, if possible. Additional research is needed, and new, sensitive tools for detecting LVH will accelerate such studies. Further investigations are also needed on the reversibility of LVH, preferred antihypertensive agents for accomplishing reversal, and whether expected benefits result.

Congestive heart failure, coronary events and atherothrombotic brain infarction in elderly blacks and whites with systemic hypertension and with and without echocardiographic and electrocardiographic evidence of left ventricular hypertrophy.

Hypertension was present in 50% of 196 blacks and in 36% of 382 whites (p less than 0.001). A prospective study of 84 elderly blacks (70% women) and 326 elderly whites (73% women) with hypertension correlated echocardiographic and electrocardiographic left ventricular (LV) hypertrophy with incidences of congestive heart failure (CHF), coronary events and atherothrombotic brain infarction (ABI). Echocardiographic LV hypertrophy (p less than 0.02) and concentric LV hypertrophy (p less than 0.001) were more prevalent in hypertensive blacks than in hypertensive whites. Hypertensive blacks were younger (78 +/- 9 years) than hypertensive whites (82 +/- 7 years) (p less than 0.001). Other coronary risk factors were similar, except for higher serum triglycerides in whites than in blacks (p less than 0.02). Follow-up was 37 +/- 18 months in blacks and 43 +/- 18 months in whites (p less than 0.01). Incidences of CHF and coronary events were not significantly different in blacks and whites. ABI incidence was 38% in blacks and 21% in whites (p less than 0.005). Multiple logistic regression analysis showed that prior CHF (p = 0.000), concentric LV hypertrophy (p = 0.018) and echocardiographic LV hypertrophy (p = 0.022) were independent risk factors for CHF. Echocardiographic LV hypertrophy (p = 0.001), serum total cholesterol (p = 0.002), concentric LV hypertrophy (p = 0.005) and prior coronary artery disease (p = 0.042) were independent risk factors for coronary events. Prior ABI (p = 0.001), echocardiographic LV hypertrophy (p = 0.001) and electrocardiographic LV hypertrophy (p = 0.034) were independent risk factors for ABI.

Socioeconomic status and morbidity and mortality in hypertensive blacks.

Despite an overall limited range of social and economic opportunities in the recent past, blacks of lower socioeconomic status have experienced marked excesses in hypertension-related burdens compared with their more advantaged peers: the incidence, prevalence, and severity of hypertension and its end-organ sequelae increased with decreasing educational achievement and the 5-year mortality was two times higher for black hypertensives of lower than higher educational achievement under conditions of usual care in U.S. communities in the 1970s. The Stepped Care program of antihypertensive pharmacologic therapy of the HDFP reduced all-cause mortality by 19% for black hypertensive men and 28% for black women. The HDFP also eliminated the association of mortality with educational achievement; the favorable impact of the program was greatest in the group at highest risk, blacks of lowest socioeconomic status.

[Fatty acids of the omega-3 line in the erythrocytes of Chukchi with myocardial hypertrophy]. / Zhirnye kisloty omega-3 riada v eritrotsitakh Chukchei pri gipertrofii miokarda.

A study was made of the fatty acid composition of erythrocytes in the Chukchi aged 30 to 59 with myocardial hypertrophy and in controls. In erythrocytes of the Chukchi the percentage of polyunsaturated fatty acids of omega-3 series including eicosapentaenoic acid was increased (C 20:5), and the percentage of linoleic acid and arachidonic acid was decreased (C 18:2 and C 20:4, respectively) as compared to similar indices of erythrocytes in Muscovites. Myocardial hypertrophy was diagnosed in the Chukchi in whom the percentage C 20:5 in erythrocytes was higher and exceeded that in PL. It was assumed that changes in the fatty acid composition of cell membranes played certain part in disorder of their function and the development of myocardial hypertrophy in the Chukchi.

Echocardiography, hypertension, and left ventricular mass.

The greater sensitivity of echocardiography than electrocardiography has revealed left ventricular hypertrophy (LVH) to be present in 20% or more of patients with systemic hypertension, with the exact prevalence dependent both on how a population is selected and on the sex, race, and possibly age composition of its members. LVH is more closely related to blood pressure recorded in the patient's natural setting during normal activity or exercise-whether measured by portable recorder or home manometer-than to blood pressure measured by the physician. A subgroup of patients with mild essential hypertension exhibit high cardiac output and evidence of supernormal myocardial contractility in the absence of LVH, whereas among patients with more sustained hypertension, high ejection fractions may be associated with marked concentric LVH. Recent data indicate that echocardiographic detection of LVH identifies mildly hypertensive patients at significant risk, a finding that may aid identification of patients for drug treatment.