Intake of polyunsaturated fat in relation to mortality among statin users and non-users in the Southern Community Cohort Study

BACKGROUND AND AIMS

Consumption of polyunsaturated fatty acids (PUFA), especially the n3-series, may protect against cardiovascular disease (CVD), but recent randomized studies have failed to demonstrate these benefits. One of the prevailing hypotheses is that PUFA intake may not confer benefits beyond those provided by statins, but studies comparing statin users to non-users with regard to effects of PUFA are lacking.

METHODS AND RESULTS

Black and white men and women (n = 69,559) in the Southern Community Cohort Study were studied. Cox regression models adjusting for age, sex, race, BMI, recruitment site, education, income, smoking, diabetes, and dietary variables were used.

RESULTS

At baseline the mean ± SD age was 52 ± 9 years, 60% of participants were women, 54% had hypertension and 16% used statins. We observed modest inverse associations between n3-PUFA and n6-PUFA intake with mortality among non-statin users but not among statin users. In adjusted analyses, the HRs (95% CIs) for all-cause mortality (6,396 deaths over a median of 6.4 years) comparing the highest to the lowest quintile were 0.90 (0.82-1.00) for n3-PUFA and 0.80 (0.70-0.92) for n6-PUFA among non-statin users, whereas they were 1.06 (0.87-1.28) and 0.96 (0.78-1.19) for n3-PUFA and n6-PUFA, respectively, among statin users.

CONCLUSIONS

Our results suggest potential benefits of PUFA consumption on mortality which are only apparent in the absence of statin therapy. It seems prudent to consider the potential benefit of PUFA consumption in the primary prevention of CVD among patients who are not candidates for statin therapy but are at increased risk for CVD and mortality.

Antimicrobial residues in foods of animal origin in Africa: public health risks

The authors report on the current status of work on residues of veterinary medicinal products and, in particular, antimicrobial residues in foods of animal origin. This review focuses on residues of veterinary antimicrobials, antimicrobials used in livestock production, the concept of residues, and antimicrobial residues in foods of animal origin. Only one antimicrobial substance has been approved in the West African Economic and Monetary Union, compared with 16 substances in Benin and 56 in the European Union. The issue of antimicrobial residues in foods of animal origin has rarely been a serious concern in developing countries, in contrast to the situation in Europe. However, while the prevalence of veterinary drug residues in foods of animal origin is less than 1% in Europe, in some African countries it can be as high as 94%. Antimicrobial residues in foods of animal origin can cause allergies, cancer, alterations in the intestinal flora, bacterial resistance and the inhibition of fermentation in the dairy industry. The harmonisation of regulations in Africa could reduce the circulation of prohibited antimicrobials and lead to the implementation of a plan for the control and surveillance of residues from veterinary medicinal products in foods of animal origin.

A review on aflatoxin contamination and its implications in the developing world: a sub-Saharan African perspective

Mycotoxins contamination in some agricultural food commodities seriously impact human and animal health and reduce the commercial value of crops. Mycotoxins are toxic secondary metabolites produced by fungi that contaminate agricultural commodities pre- or postharvest. Africa is one of the continents where environmental, agricultural and storage conditions of food commodities are conducive of Aspergillus fungi infection and aflatoxin biosynthesis. This paper reviews the commodity-wise aetiology and contamination process of aflatoxins and evaluates the potential risk of exposure from common African foods. Possible ways of reducing risk for fungal infection and aflatoxin development that are relevant to the African context. The presented database would be useful as benchmark information for development and prioritization of future research. There is need for more investigations on food quality and safety by making available advanced advanced equipments and analytical methods as well as surveillance and awareness creation in the region.

Epidemiology of stroke and high blood pressure in Africa

Stroke and high blood pressure are major causes of death and disability worldwide. Although comprehensive stroke surveillance data for Africa are lacking, the available data show that age-standardised mortality, case fatality and prevalence of disabling stroke in Africa are similar to or higher than those measures in most high-income regions. In Africa, more than 90% of patients with haemorrhagic stroke and more than half with ischaemic stroke are found to have high blood pressure. However, awareness of hypertension and its prevention, treatment and control remain very low in Africa even though recent surveys show an increasing prevalence of the disease consistent with the nutritional and epidemiological transition in the region. Renewed emphasis on improved surveillance and the prevention and control of high blood pressure and stroke in Africa is needed.

The relation of obesity throughout life to carotid intima-media thickness in adulthood: the Bogalusa Heart Study

OBJECTIVE

Although obese children are at increased risk for coronary heart disease in later life, it is not clear if this association results from the persistence of childhood obesity into adulthood. We examined the relation of adiposity at various ages to the carotid intima-media thickness (IMT) at age 35 y.

DESIGN

Prior to the determination of IMT by B-mode ultrasound, subjects (203 men, 310 women) had, on average, six measurements of body mass index (BMI) and triceps skinfold thickness (TSF) between the ages of 4 and 35 y. Mixed regression models for longitudinal data were used to assess the relation of these characteristics to adult IMT.

RESULTS

Overall, adult IMT was associated with levels of both BMI and TSF (P<0.001), with the magnitudes of the associations with childhood adiposity comparable to those with adult levels of BMI and TSF. Furthermore, adult obesity modified the association between childhood adiposity and IMT: high IMT levels were seen only among overweight (BMI > or =95th percentile) children who became obese (BMI > or =30 kg/m2) adults (P<0.01 for linear trend). In contrast, IMT levels were not elevated among (1) overweight children who were not obese in adulthood, or among (2) thinner children who became obese adults.

CONCLUSIONS

These results emphasize the adverse, cumulative effects of childhood-onset obesity that persists into adulthood. Since many overweight children become obese adults, the prevention of childhood obesity should be emphasized.

Exercise in sickle cell anemia: effect on inflammatory and vasoactive mediators

The aim of this study was to determine the response of inflammatory and vasoactive mediators to 3 consecutive days of exercise in African-American women with and without sickle cell anemia (SCA). Circulating inflammatory mediators [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha)] were measured before, and vasoactive mediators [endothelin-1 (ET-1), nitric oxide metabolites (NOx)] before and after each exercise bout in ten subjects with SCA and ten controls. Exercise did not affect ET-1, IL-6 or CRP concentrations (p >.05). TNFalpha was higher in SCA than controls (p < or = .0005) at all times; however, the response pattern was similar for the groups: no change from day 1 to day 2, but a decrease from day 2 to day 3 (p < or = .05). NOx increased significantly after exercise (p < or = .0001) but returned to baseline by 24 h afterward. On the 3rd day, NOx increased after exercise in SCA but not in the controls (p < or = .05). In conclusion, exercise did not cause a harmful inflammatory response in these individuals with SCA. However, NOx increased after exercise on all 3 days in SCA but appeared attenuated after 2 days in controls.

Sudden cardiac death in the United States, 1989 to 1998

BACKGROUND

Sudden cardiac death (SCD) is a major clinical and public health problem.

METHODS AND RESULTS

United States (US) vital statistics mortality data from 1989 to 1998 were analyzed. SCD is defined as deaths occurring out of the hospital or in the emergency room or as "dead on arrival" with an underlying cause of death reported as a cardiac disease (ICD-9 code 390 to 398, 402, or 404 to 429). Death rates were calculated for residents of the US aged >/=35 years and standardized to the 2000 US population. Of 719 456 cardiac deaths among adults aged >/=35 years in 1998, 456 076 (63%) were defined as SCD. Among decedents aged 35 to 44 years, 74% of cardiac deaths were SCD. Of all SCDs in 1998, coronary heart disease (ICD-9 codes 410 to 414) was the underlying cause on 62% of death certificates. Death rates for SCD increased with age and were higher in men than women, although there was no difference at age >/=85 years. The black population had higher death rates for SCD than white, American Indian/Alaska Native, or Asian/Pacific Islander populations. The Hispanic population had lower death rates for SCD than the non-Hispanic population. From 1989 to 1998, SCD, as the proportion of all cardiac deaths, increased 12.4% (56.3% to 63.9%), and age-adjusted SCD rates declined 11.7% in men and 5.8% in women. During the same time, age-specific death rates for SCD increased 21% among women aged 35 to 44 years.

CONCLUSIONS

SCD remains an important public health problem in the US. The increase in death rates for SCD among younger women warrants additional investigation.

Body composition in women with sickle cell disease

INTRODUCTION

Adults with sickle cell disease (SCD) have increased morbidity and low perceived health status, similar to patients with other chronic conditions. These patients may be sedentary due to exercise intolerance, physical incapacity due to sickle cell-related complications or medical conservatism. Obesity is an indicator of low health status and overall well-being in the general population, and we hypothesize that adults with SCD will have a high total body fat (%BF). The purpose of this study was to assess body composition in women with SCD using dual-energy X-ray absorptiometry (DXA).

METHODS

Baseline medical examination, laboratory assessments, and seven-day activity recall to estimate energy expenditure (EE) were obtained for 22 women with SCD. BMI was calculated and whole body DXA was performed [fat mass (FM), fat-free soft tissue (FFST), and bone mineral content (BMC)]. Descriptive statistics were obtained and associations between body composition indices, total hemoglobin (Hb), treatment with hydroxyurea (HU), and EE were determined.

RESULTS

Patient age was 30.5+/-9.3 years and total Hb was 8.85+/-1.92 g/dL (mean+/-SD). Mean body mass index (BMI) (22.6 kg/m2) was in the 'acceptable' range, while DXA measurement of mean % fat (32.6%) indicated obesity. Fat-free mass (FFM) was 40.0+/-5.62 and bone mineral density (BMD) was 1.13+/-0.14 g/cm2 (mean+/-SD). There were no correlations between body composition indices and total Hb, HU, or EE.

CONCLUSIONS

This is the first report of high levels of adiposity, low FFM, and low BMD in normal weight women with SCD. The findings were not affected by total Hb, EE, HU. Further studies are needed to better define body composition, body composition determinants, and their impact on overall health status in adults with SCD.

Race, ethnicity, and geography: disparities in heart disease in women of color

Cardiovascular disease (CVD) is the leading cause of death in women. Misconceptions about the importance of CVD still persist. These myths affect awareness of CVD and the urgency with which women present for treatment after symptoms develop. Modifiable and nonmodifiable risk factors are more prevalent among ethnic minority women in concentrated geographical locations. The recent publication of the CDC women's atlas presents a unique opportunity for healthcare providers to use derived county-specific data in education, research, and delivery of health promotion and disease prevention services to women of color. Specific recommendations for the nursing profession are provided to assist in eliminating CVD disparities for all women.

Prognostic implications of the compensatory nature of left ventricular mass in arterial hypertension

OBJECTIVE

To test whether inappropriate echocardiographic left ventricular (LV) mass (i.e. higher than predicted by individual body size, sex and cardiac load [delta%LVM]) is associated with an increased rate of cardiovascular events, and whether values of LV mass lower than appropriate confer protection.

DESIGN

Prospective, longitudinal.

SETTING

Institutional, hospital outpatient clinic.

PATIENTS

A total of 294 hypertensive patients, 84 with inappropriate and 21 with low LV mass (lower than appropriate).

MAIN OUTCOME MEASURES

Cardiovascular fatal and non-fatal events.

RESULTS

Baseline delta%LVM was higher in patients with follow-up total (n = 50) or fatal (n = 14) events than in event-free survivors (all P < 0.0001) and predicted events independently of age and systolic pressure (all P < 0.0001). Although the performance was not better than with use of more traditional definition of LV hypertrophy, delta%LVM remained a predictor even in the subgroup of 126 patients (32 total events, 13 deaths) with clear-cut LV hypertrophy (P < 0.009). Patients with low LV mass exhibited supranormal LV chamber and midwall function, slightly higher heart rate and higher cardiac index (all P< 0.01). These patients had the same rate of events as those with appropriate LV mass.

CONCLUSIONS

In hypertensive patients, increase in LV mass beyond values required to compensate cardiac workload at a given body size and sex predicts cardiovascular risk independently of age and blood pressure, in the whole population as well as in the subset of patients with LV hypertrophy. Hypertensive patients with levels of LV mass lower than needed to compensate cardiac workload exhibit hyperdynamic circulatory status and the same risk pattern as patients with higher values of LV mass, possibly due to activation of the sympathetic system.

Race, baseline characteristics, and clinical outcomes after coronary intervention: The New Approaches in Coronary Interventions (NACI) registry

BACKGROUND

The impact of race and sex on clinical outcomes after percutaneous coronary interventions remains incompletely understood. Specific data on patient demographics, lesion characteristics, and outcomes of black versus white patients are poorly described. To further evaluate these issues, we analyzed the New Approaches in Coronary Interventions (NACI) registry.

METHODS

Patients (200 black, 4279 white) undergoing coronary interventions in the NACI trial were compared. A Cox proportional hazards model was used to determine which baseline demographics were independent risk factors for the combined end point of death, Q-wave myocardial infarction, and coronary artery bypass grafting at 1 year.

RESULTS

Black patients were significantly younger (age 59 +/- 11 vs 63 +/- 11 years; P <.001), more often obese (29.6 +/- 6 vs 27.5 +/- 4.8 kg/m(2); P <.001), female (50% vs 34%; P <.001), diabetic (34% vs 21%; P <.001), and hypertensive (71% vs 52%; P <.001). Black patients were significantly more likely to have single-vessel disease (48% vs 40%; P <.05) and less likely to have undergone coronary artery bypass grafting (26% vs 34%; P <.05). Blacks were significantly more likely to have a discrete lesion (85% vs 62%; P <. 001) with less thrombus (7% vs 12%; P <.05), tortuosity (17% vs 25%; P <.05), and an ulcerated appearance (5% vs 10%; P <.05). Despite these significant baseline differences, no significant difference was seen in the procedural success (80% vs 82%) or major adverse events (death, Q-wave myocardial infarction, any revascularization) at 1 year (39% vs 34%). Predictors of adverse events for white patients included diabetes (relative risk [RR] = 1.24; confidence intervals [CI], 1.0-1.5) and high-risk status (RR = 1.58; CI, 1.26-1. 91). Predictive characteristics of adverse events for black patients included only sex (RR = 3.45; CI, 1.27-9.35; P =.02).

CONCLUSIONS

There are significant differences in baseline characteristics of black patients compared with white patients. Despite these differences in traditional risk factors, they do not affect procedural success or 1-year outcome. In black patients, only sex predicted adverse events. Additional investigation is required to understand the mechanisms for this difference.

Racial differences in endothelin-1 at rest and in response to acute stress in adolescent males

Blacks exhibit greater vasoconstriction-mediated blood pressure (BP) increases in response to stress than do whites. Endothelin-1 (ET-1), a potent vasoconstrictive peptide, has been proposed as having a role in racial differences in stress reactivity. We evaluated the hemodynamic and plasma ET-1 levels of 41 (23 whites, 18 blacks, mean age 18.6 years) normotensive adolescent males at rest and in response to a video game challenge and forehead cold stimulation. Measurements were performed at catheter insertion and before and immediately after the 2 stressors, which were separated by 20-minute rest periods. Blacks exhibited higher absolute levels of diastolic blood pressure, total peripheral resistance index, or both in response to catheter insertion and to the video game challenge and during recovery from video game challenge and cold stimulation (P<0. 05 for all). Blacks exhibited higher absolute levels of ET-1 at every evaluation point (P<0.05 for all) and greater increases in ET-1 in response to both stressors (ps<0.05). These findings suggest that altered endothelial function may be involved in racial differences in hemodynamic reactivity to stress and possibly in the development of essential hypertension.

Refining strategies for the prevention and control of hypertension and related complications

Hypertension is the leading preventable cause of premature morbidity and mortality from coronary heart disease, chronic heart failure, stroke and kidney failure. Despite the remarkable advances made in the design, development, and distribution of antihypertensive drugs and the plethora of published guidelines for hypertension treatment over the last two decades, blood pressure control rates remain rather disappointing. In the United States, Canada, and the United Kingdom, as well as in countries with far less resources devoted to health care, fewer than one in four hypertensives are controlled. This observation remains a major source of frustration for clinicians and health policy makers alike and serves as a constant reminder for more refined strategies for hypertension treatment and control. The 14th International Interdisciplinary Conference on Hypertension in Blacks (ISHIB99), held in Toronto, Canada on July 10-14, 1999 provided a unique forum for the discussion of this issue. The recommendations discussed are summarized herein under 10 specific headings that include: (1) Renewed emphasis on health education for patients and their families; (2) Increased involvement of non-physician health care providers; (3) Aggressive detection, evaluation and control of attendant cardiovascular risk factors; (4) Renewed determination for clinicians to set and achieve blood pressure targets; (5) Increased patient involvement in management decisions; (6) Improved access to quality care for the "working poor" and indigent; (7) Renewed commitment to community participation; (8) Partnership with managed care and professional organizations; (9) Renewed emphasis on the importance of psychosocial factors; (10) Enhanced communication and networking among hypertension care providers and between providers and patients.

Hemodynamic function at rest, during acute stress, and in the field: predictors of cardiac structure and function 2 years later in youth

Left ventricular hypertrophy is an independent predictor of cardiovascular morbidity and mortality. However, predictors of cardiac structure and function in youth are not completely understood. On 2 occasions (2.3 years apart), we examined 146 youth aged initially 10 to 19 years (mean age, 14.2+/-1.8 years). On the initial visit, hemodynamic function was assessed at rest, during laboratory stress (ie, orthostasis, car-driving simulation, video game, and forehead cold), and in the field (ie, ambulatory blood pressure). Quantitative M-mode echocardiograms were obtained on both visits. On both visits, black compared with white youth had higher resting laboratory systolic blood pressure (P<0.02), greater relative wall thickness (P<0.003), greater left ventricular mass indexed by either body surface area or height(2.7) (P<0.01 for both), and lower midwall fractional shortening ratio (P<0.05). Hierarchical stepwise regression analysis indicated that significant independent predictors of follow-up left ventricular mass/height(2. 7) were the initial evaluation of left ventricular mass/height(2.7), body mass index, gender (males more than females), and supine resting total peripheral resistance (final model R(2)=0.53). Left ventricular mass/body surface area was predicted by initial left ventricular mass/body surface area, weight, gender, mean supine resting total peripheral resistance, and systolic pressure response to car-driving simulation (final model R(2)=0.48). Midwall fractional shortening was predicted by initial midwall fractional shortening, race (white more than black), and lower mean supine total peripheral resistance (final model R(2)=0.13). The clinical significance of these findings and their implications for improved prevention of cardiovascular diseases are yet to be determined.

Patterns of body fat deposition in youth and their relation to left ventricular markers of adverse cardiovascular prognosis

The patterns of body fat deposition in healthy youth and their relation to future development of cardiovascular disease remain incompletely understood. To further evaluate these patterns, we measured indirect indexes of central and general fat deposition in healthy adolescents (mean age 15.4+/-2.3 years) with family histories of hypertension. We examined the relation between these indexes and echocardiographic markers of adverse prognosis as well as the effect of gender and ethnicity. All 225 subjects (64% black and 48% female) had > or =1 biologic parent and 1 grandparent with hypertension. Skinfold thicknesses, waist-to-hip girth ratio, Quetelet index, Ponderal index, conicity, and Z score weight - Z score height were measured. Left ventricular (LV) mass, indexed LV mass, relative wall thickness (RWT), and midwall fractional shortening (MFS) were determined using echocardiography. In both black and white subjects, the adiposity indexes were significantly correlated with posterior wall thickness, total LV mass, and indexed LV mass (p <0.05 for all). Additionally, in black subjects, central adiposity was inversely related to MFS and directly related to RWT and septal thickness. General adiposity independently predicted indexed and nonindexed LV mass, whereas central adiposity predicted MFS and RWT. Compared with subjects with normal LV geometry, those with abnormal geometry were heavier and fatter based on every index of obesity (p <0.03 for all). Thus, indexes of fat deposition are significantly correlated with LV markers of adverse prognosis in healthy youth.

Stroke volume/pulse pressure ratio and cardiovascular risk in arterial hypertension

Ratio of stroke volume (SV, M-mode echocardiography) to pulse pressure (PP) has been proposed as an estimate of total arterial compliance and has been shown to be related to body size, age, and heart rate in normal adults. SV/PP was estimated in 294 hypertensive patients (98 women) as a raw value by use of SV/body surface area (SVi) and by the ratio of SV/PP to the value predicted by a previously developed equation (%SV/PP). At baseline, the 50 patients who had cardiovascular events over the following 10 years exhibited higher PP and lower SV/PP, SVi/PP, and %SV/PP (all P<0.008) than patients without events. Crude risk of follow-up total and fatal cardiovascular events increased with increasing level of PP and decreasing SV/PP, SVi/PP, and %SV/PP (all P<0.002). In multivariate logistic regression models with continuous covariates, the risk of total cardiovascular events was independently related to increasing age (P<0.0001) and left ventricular (LV) mass index (P<0.003) and decreasing values of %SV/PP (P<0.006) but not to increasing systolic, pulse, or mean blood pressure or gender. Similar although less strong results were obtained with the use of SVi/PP (P<0.02), whereas SV/PP did not enter the model as an independent predictor. Risk of cardiovascular death was only predicted by age and LV mass index. The %SV/PP was also an independent predictor of total cardiovascular events in Cox proportional hazards analysis (exp[b]: 2.49, P<0.001) independent of age (exp[b]: 1.05, P<0.003) and LV mass index (exp[b]: 1.02, P<0.0003), whereas no effect was detected for height. Thus, in patients with arterial hypertension, a reduced ratio of M-mode echocardiographic SV/PP as a percentage of the value predicted by demographic variables is a predictor of cardiovascular morbid events independent of age and LV mass index.

Relations of body composition to left ventricular geometry and function in children

OBJECTIVE

To determine whether body composition and fasting insulin levels explained variation in left ventricular (LV) function and geometry.

PARTICIPANTS

Sixty-two children, 7 to 13 years of age.

RESULTS

For LV mass/height the partial correlation (age controlled) with percentage of fat was r = 0.34 (p = 0.008) and the correlation with (Ln)insulin was r = 0.25 (p = 0.051); multiple regression showed that independent proportions of the variance were explained by gender (boys > girls), ethnicity (black > white subjects), and percentage of fat (p = 0.015). Nonnormalized LV mass was correlated (age controlled) with fat-free mass (r = 0.76; p < 0.001), fat mass (r = 0.58; p < 0.001), and (Ln) insulin (r = 0.27; p = 0.0359); multiple regression showed that fat-free mass and fat mass explained independent proportions of the variance. Percentage of fat was correlated (age controlled) with greater relative wall thickness (r = 0.34; p = 0.008) and lower midwall fractional shortening (-0.37; p = 0.004).

CONCLUSION

Body fatness was cross-sectionally associated with levels of LV function and geometry that in adults have been found to lead to morbidity and death. The relationship of fatness to LV mass may be due to the higher insulin concentrations in the fatter children. These cross-sectional results are consistent with the hypothesis that excess fatness may adversely influence cardiovascular health early in life.

Prediction of mortality risk by different methods of indexation for left ventricular mass

OBJECTIVES

We sought to compare the predictive value of echocardiographically determined left ventricular hypertrophy on death from all causes and cardiac mortality using various methods of indexation for left ventricular mass.

BACKGROUND

Considerable controversy exists regarding the optimal method for indexing left ventricular mass to body size in the clinical setting.

METHODS

The study included 988 consecutive patients who had both coronary angiograms and echocardiographic examinations in an inner-city public hospital in Chicago, Illinois. Patients were followed up for a mean of 7 years (range 2 to 11).

RESULTS

Various left ventricular mass indexes (e.g., mass indexed for height, height2, height2.13, height2.7, body surface area and body surface area1.5 were highly correlated (r = 0.90 to 0.99). Used as a continuous measure, an increase in any left ventricular mass index was associated with similar risk of death from all causes and cardiac diseases. Although left ventricular hypertrophy assessed by mass indexed for body surface area using the published conventional partition values provided somewhat better prediction, the adjusted relative risk was in general not significantly different from hypertrophy based on other indexes. Patients with left ventricular hypertrophy defined concordantly by indexes based on both body surface area and height (or height2.7) had, by definition, the highest average mass indexes among all groups and experienced as much as a threefold greater risk of death than those without hypertrophy. A small proportion of patients (12%) who were classified into the hypertrophy group by height-based indexes alone, but not by body surface area, had a moderate increase in mass and showed no increase in risk, even though being overweight was extremely prevalent in this group.

CONCLUSIONS

Because of the high correlation among various body size indexes, left ventricular hypertrophy, defined by different indexes for left ventricular mass, similarly confers increased risk of mortality in patients with or without coronary artery disease.

Functional mitral stenosis resulting from a large mitral valve prosthesis vegetation

Obstruction of a prosthetic valve by an infective vegetation is a rare and life-threatening complication of endocarditis that demands emergent surgical intervention. In our patient's case, transthoracic echocardiography showed the large vegetation, transthoracic Doppler imaging showed severe obstruction of diastolic flow through the bioprosthetic valve, and transesophageal echocardiography showed that no perivalvular abscess was present. Rapid diagnosis of prosthetic valve infection and obstruction demanded application of all three major echocardiographic modalities and proved critical to the patient's recovery.

Use of beta-adrenergic receptor blockers in blacks

Beta adrenergic receptor blockers (beta-blockers) are an important class of drugs in the management of patients with cardiovascular diseases. These drugs have been shown to reduce mortality in hypertension and prolong survival in patients with coronary heart disease. Although hypertension and coronary heart disease account for the majority of excess cardiovascular morbidity and mortality in blocks, beta-blockers continue to be underprescribed in this ethnic group. The magnitude of blood pressure reduction in black patients with hypertension has been consistently less during monotherapy with nonselective beta-blockers than with diuretics. However, the highly selective beta-blocker bisoprolol has been shown to be as effective as diuretics and is equally effective in black and nonblack patients with hypertension. In general, no racial differences in efficacy are noted when beta-blockers are used with diuretics as combination therapy for hypertension. Black patients should not be denied beta-blocker therapy because of an anticipated suboptimal response, especially when there are clear indications for treatment (e.g., for migraine, hyperthyroidism, arrhythmia control, and after myocardial infarction).

Midwall left ventricular mechanics. An independent predictor of cardiovascular risk in arterial hypertension

BACKGROUND

An appreciable proportion of asymptomatic hypertensive patients have depressed left ventricular (LV) performance that is identified by midwall shortening/endsystolic stress relations but not by indexes that use endocardial shortening. It has not been established, however, whether depressed midwall ventricular performance has prognostic implications.

METHODS AND RESULTS

Echocardiographic endocardial and midwall LV fractional shortening/circumferential end-systolic stress relations in 294 hypertensive patients were analyzed as predictors of the occurrence of cardiovascular morbid events that occurred in 50 patients (including 14 deaths) during a 10-year mean follow-up. Patients with initially lower midwall but not endocardial shortening, either in absolute terms or as a percentage of predicted from observed end-systolic stress, were more likely to suffer morbid events than those with initially normal values (P < .004). Cardiovascular events occurred in 29 of 100 patients (29%) and death in 10 of 100 patients (10%) among those who were in both the two highest quartiles of LV mass index and the two lowest quartiles of midwall shortening, as opposed to 21 of 194 (11%) and 4 of 194 (2.1%) of the remaining patients (odds ratio, 3.4; 95% CI, 1.8 to 6.3; P < .0001; and odds ratio, 5.3; 95% CI, 1.6 to 17.3; P < .006, respectively). In logistic analysis, increasing age, high LV mass, high systolic blood pressure, and low values for an interaction term between LV mass index and midwall shortening independently predicted cardiovascular events (.04 < P < .001); increasing age, low midwall LV shortening as a percentage of predicted, and high value of the interaction term predicted the occurrence of cardiac death (.004 < P < .0002). Survival analysis controlling for age confirmed that low midwall shortening independently predicted cardiac morbidity or death, especially in the subgroup of patients with LV hypertrophy.

CONCLUSIONS

Depressed midwall shortening is a predictor of adverse outcome in arterial hypertension; the combination of higher LV mass and lower midwall shortening identifies individuals at markedly increased risk.

Pulmonary vein Doppler flow patterns specific for elevated left ventricular filling pressures in older cardiac patients are common in healthy adults < 40 years old

In older cardiac patients, elevated left-sided heart filling pressures are predicted by both a systolic PV flow fraction < 40% and a greater duration during atrial systole of reversal flow into the PVs than forward flow through the mitral valve. However, this study shows that these Doppler findings are not uncommon in younger subjects without cardiac disease. Use of these PV Doppler flow parameters to assess LV filling pressures should be limited to older patients.

Left ventricular hypertrophy has a greater impact on survival in women than in men

BACKGROUND

Echocardiographically determined left ventricular hypertrophy (LVH) has a well-demonstrated association with cardiovascular morbidity and mortality. However, whether or not there is a sex differential in the impact of LVH on mortality has never been systematically explored.

METHODS AND RESULTS

This study enrolled 436 consecutive black patients (163 men and 273 women) free of angiographic coronary artery disease from a hospital registry. LVH (left ventricular [LV] mass/body surface area > or = 117 g/m2 in men and > or = 104 g/m2 in women) was present in 84 men (52%) and 119 women (44%). During a mean of 5 years' follow-up (range, 0 to 9), 49 patients (26 men and 23 women) died. The mortality rate was 5.40 per 100 patient-years in men with LVH and 2.58 in men without LVH (crude relative risk [RR] = 2.09) and 3.21 and 0.66, respectively, in women (RR = 4.87). In Cox regression analysis, adjusting for age, hypertension, and ejection fraction, the RR of total death for LVH versus non-LVH was 2.0 (95% confidence interval [CI], 0.8 to 5.0) in men and 14.3 (95% CI, 1.6 to 11.7) in women. For cardiac death, RR was 1.3 (95% CI, 0.4 to 3.7) and 7.5 (95% CI, 1.6 to 33.8) in men and women, respectively. Analyses using LV mass indexed by height or height with the use of different LVH cut points, comparing patients in the highest sex-specific tertile of mass index to those in the lower two tertiles, and the use of LV mass indexes as continuous variables similarly demonstrated a greater increase in risk of either fatal end point among women than men.

CONCLUSIONS

These findings indicate a sex difference in the contribution of LV mass and hypertrophy to mortality in the absence of coronary artery disease.

The relative effects of left ventricular hypertrophy, coronary artery disease, and ventricular dysfunction on survival among black adults

OBJECTIVE

To evaluate the effect of echocardiographically determined left ventricular hypertrophy (LVH) on survival in comparison with number of stenosed vessels and left ventricular systolic dysfunction.

DESIGN

Cohort study based on a consecutive sample from a hospital registry, with a mean follow-up of 5 years.

SETTING

An inner-city public hospital in Chicago, Ill.

PATIENTS

The study included 1089 consecutive black patients who underwent both coronary angiography and M-mode echocardiography as part of a diagnostic evaluation.

RESULTS

Nonstenosed coronary arteries, single-vessel disease, and multivessel disease were found in 48%, 16%, and 36% of patients, respectively; LVH (left ventricular mass index > 131 g/m2 in men and > 100 g/m2 in women) was detected in 50% of patients. Hypertrophy without coexistent obstructive coronary disease was associated with a lower survival rate than that observed for single-vessel disease and was similar to multivessel disease. When LVH, number of diseases vessels, and left ventricular dysfunction were subjected to multivariate analysis, hypertrophy conferred a relative risk (RR) of 2.4 (95% confidence interval [CI], 1.7 to 3.2). By comparison, the presence of a single stenosed vessel did not increase the risk of death. Multivessel disease and ejection fraction less than 45% were associated with an RR of 1.6 (95% CI, 1.1 to 2.2) and 2.0 (95% CI, 1.4 to 2.7), respectively. Calculation of the attributable risk fraction demonstrated that for every 100 deaths in this cohort, LVH independently accounted for 37. The corresponding attributable risk fractions were 1%, 22%, and 9% for single-vessel disease, multivessel disease, and ventricular dysfunction, respectively.

CONCLUSIONS

Left ventricular hypertrophy was associated with a greater RR and attributable risk than the traditional measures of coronary disease severity. The high prevalence and powerful risk of LVH make an important contribution to the adverse survival rates among black patients with heart disease and may account for much of the black-white differential.

Spectrum of hypertensive target organ damage in Africa: a review of published studies

This paper reviews the evidence of hypertensive target organ damage (HTOD) in Africa, and the difficulties of its assessment, with a focus on implications for further research and prevention. Specific examples of HTOD reviewed include left ventricular hypertrophy, heart failure, ischaemic heart disease, arrhythmias and sudden death, kidney failure, cerebrovascular accidents, retinopathy and central as well as peripheral vascular disease. There is evidence that the prevalence of hypertension is increasing in some parts of Africa, thus increasing the number of people who suffer from fatal and nonfatal complications. Analysis of the type, frequency and distribution of HTOD is critical to the design of interventions to prevent and manage hypertension, and in the design of future clinical research. As would be expected, the frequency of atherosclerotic complications, particularly involving the heart, is lower in Africa than in developed countries. Stroke, renal failure and heart failure appear to be the principal adverse outcomes and are likely to be associated with a high case fatality rate. Community-based data on these issues are limited, however, and hospital series cannot estimate the population burden and may be unreliable in describing the case mix. Improved data on HTOD will more accurately reflect the health impact of hypertension, provide the basis for aggressive efforts at prevention, detection and control of high BP and establish their relevance in the overall scheme of resource allocation during fiscal austerity and limited healthcare spending. Additionally, knowledge of the prevalence and relative frequencies of HTOD has direct and important implications for clinical outcomes research in hypertension.

Comparison of classification of the severity of hypertension by blood pressure level and by World Health Organization criteria in the prediction of concurrent cardiac abnormalities and subsequent complications in essential hypertension

OBJECTIVE

To determine whether classification of the severity of hypertension according to the World Health Organization (WHO) system, which utilizes additional clinical and laboratory findings, is superior to classification by blood pressure level alone in predicting prognostically important cardiac structural abnormalities and the risk of subsequent complications in asymptomatic subjects.

DESIGN

Two-hundred and twenty adults with uncomplicated essential hypertension underwent baseline clinical evaluation and echocardiography; 88% were subsequently followed for a mean of 11.6 years.

SETTING

University hospital.

RESULTS

Left ventricular mass index and relative wall thickness were slightly greater in patients in the highest diastolic or systolic blood pressure stratum than in WHO stage II hypertensives, but these results were statistically non-significant. High peripheral resistance index was best identified by diastolic blood pressure level. Receiver operating characteristic curve analysis showed that all three methods had similar test performance in predicting abnormal left ventricular mass index, left ventricular geometry, relative wall thickness and peripheral resistance. During follow-up the proportion of patients who had a clinical event or died increased with increasing severity stratum in all three clinical classification systems, but the trends were statistically non-significant. Risk stratification by echocardiographic left ventricular mass index was most successful in identifying patients at very high and very low risk of subsequent morbid events and all-cause mortality.

CONCLUSION

Classification of hypertension severity by blood pressure level has similar, although limited, effectiveness at a lower cost than the WHO criteria in identifying patients with adverse cardiac changes and an impaired long-term prognosis. Echocardiographic measurement of left ventricular mass index was more successful than other classifications in predicting subsequent morbid events.

Left ventricular hypertrophy and hypertension

The level of left ventricular (LV) mass as measured by echocardiography or other techniques in hypertensive patients reflects the integrated effects of the level of arterial pressure, the concomitant volume load imposed on the heart, and of alterations in arterial waveform morphology as well as of body size and non-hemodynamic variables. The LV may respond to these stimuli by concentric or eccentric hypertrophy or by the recently-described pattern of concentric remodeling, in which LV mass is normal but relative wall thickness is increased. The are strong parallelisms between increases in cardiac and systemic arterial wall thicknesses, and patients with discrete atheromas detectable by carotid ultrasound have elevated LV masses. Patients with eccentric and concentric LV hypertrophy have two to four-fold increases in the incidence of cardiovascular morbid events compared to hypertensive patients with normal LV geometry, and the change in LV mass during treatment has been associated with the risk of subsequent morbidity in initial studies. In contrast to the strong predictive power of LV geometric assessment, use of indirect measures of target organ status in the WHO system for classification of the severity of hypertension does not improve on the prediction of prognosis that can be obtained by consideration of the level of arterial pressure. Current evidence suggests that evaluation of LV geometry may contribute to improved clinical decision-making in situations where more precise stratification of risk would clarify whether or not to institute treatment, or whether it should be with drugs or non-pharmacologic measures.

Comparison of left ventricular mass and geometry in black and white patients with essential hypertension

To assess racial difference in cardiac responses to elevated blood pressure, we compared echocardiographic measurements of left ventricular (LV) mass and the wall thickness to chamber dimension ratio (relative wall thickness) in 380 white and 47 black patients with uncomplicated essential hypertension consecutively enrolled in echocardiographic research studies at The New York Hospital Hypertension Center. Diastolic blood pressure and weight were slightly greater in black as compared with white subjects (104 +/- 18 v 98 +/- 11 mm Hg; P = .014 and 82 +/- 17 v 77 +/- 15 kg; P = .037, respectively), however the groups were similar with respect to age, duration of hypertension, cholesterol level, cigarette smoking, past use of antihypertensive therapy, family history of heart disease, and height. On average, LV mass indexed for body surface area and relative wall thickness were significantly greater in blacks than whites (119 v 105 g/m2; P = .02 and 0.46 v 0.39; P = .003) and blacks had twice the prevalence of LV hypertrophy (41% v 19%; P < .001) or concentric remodeling (21% v 12%; P < .05). The magnitude of increased LV mass and relative wall thickness in blacks was similar in men (132 v 110 g/m2; P = .01 and 0.44 v 0.39; P = .04) and in women (107 v 94 g/m2; P = .11 and 0.48 v 0.39; P = .02). In multivariate analyses, systolic blood pressure, age, and race were consistently predictors of increased LV mass and abnormal cardiac geometry. Cholesterol level was not independently associated with increased LV mass but was weakly associated with increased relative wall thickness.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute purulent mediastinitis and sternal osteomyelitis after closed chest cardiopulmonary resuscitation: a case report and review of the literature

Numerous complications have been associated with cardiopulmonary resuscitation. Acute purulent staphylococcal mediastinitis and sternal osteomyelitis are, however, unusual and do not appear to have been reported previously in association with closed chest resuscitation. Sternal fracture during chest compressions and subsequent hematogenous seeding of the resultant retrosternal hematoma with Staphylococcus aureus led to purulent mediastinitis and sternal osteomyelitis in our patient. The source of bacteremia may have been a resolving phlebitis at an intravenous catheter insertion site. Early diagnosis, aggressive surgical debridement, and antibiotic therapy were key to a successful outcome.

Comparative toxicology of the respiratory tract

It is difficult to extrapolate observations and results from one species to another and from animals to humans because of interspecies differences. A complete and systematic description of such differences among commonly used laboratory animals is lacking. We have reviewed the relevance of deposition, clearance, and the type and magnitude of biological response to inhaled aerosols. Current predictions on the probability of deposition of inhaled aerosols differ, but the fraction of aerosol that is actually deposited in the respiratory tract appears independent of body size. Different species of animals breathing the same aerosol do not receive identical lung doses, and thus exposure concentration is not an adequate description of lung dose. Parameters that affect the magnitude of local doses include changes in ventilation, collection efficiency, lung anatomy, and clearance mechanisms. Apart from these variations, the interspecies differences in substance metabolism and innate biological responsiveness make it unlikely that the extent of lung damage will be identical even in cases where lung doses are equal. We need a comprehensive view of species differences with predictive power.

Deposition and clearance of inhaled aerosol in the respiratory tract of chickens

Sixteen unanesthetized adult White Leghorn chickens (Gallus domesticus) were exposed to an aerosol of 99mTc-labeled submicrometric particles and killed 0, 1, 12, or 36 h later. The amount and distribution of radioactive particles retained in the lungs and skeletal system were measured to describe regional deposition and clearance. Particles were present in the lungs, air sacs, and skeletal system immediately after exposure. Reduction in activity with time suggested clearance of aerosol from the lungs and pneumatized bones. Aerosol particles were not distributed uniformly within the lungs; there was greater retention in the caudal regions. No dorsoventral gradients were observed. Of the initial lung deposition, 54 +/- 13.9% (SD) remained 1 h postexposure and 35.6 +/- 20.9% remained 36 h later. These data suggest an early fast phase of lung clearance followed by a slower phase. Detailed morphological studies are needed to understand the underlying clearance mechanisms and the bases for the differences in regional deposition.